From: S-T Morrissey Subject: thermal convection in LP sensors Date: Thu, 31 Dec 1998 14:58:45 -0600 (CST) Regarding thermal convection in LP instruments: This has long been a problem with high gain observatory instruments, even in large secure vaults. The earths' heat flow out of the ground is always present, even when a large pier is in the way. If the environment above the pier is cooler, problems result. In a cavern or mine, the temperature difference is minimal if the area is closed off, but it can still be present. Within an instrument enclosure, the base will warm up a boundary layer of air, which will eventually peel away and invert with the cool air in the top of the case, usually at periods of 10 to 100 seconds. Insulation inside, on top of the baseplate, as well as baffles within the case, will help, but more often just make the problem more interesting. The most common system with the problem came with the WWNSSS (Worldwide network of standard seismograph stations) in the 1950s, where a set of 30-second long period sensors was connected to 90-second galvanometers. The steel cases of the LP sensors were equipped with small 10-watt cartridge heaters in the very top of the case, and a small variac transformer was used to adjust the heat so that the convective noise just disappeared from the (photographic) record. Too much heat would set up its own noise. Thermostatic arrangements only added another cycle to the problem, not only to the thermal convection but to radiant heating of the sensor. To minimize the heat required, as much fiberglass insulation as possible was installed under the seismometer baseplate, which was usually about 2cm above the pier. In a small underground vault in the Ozarks, the LPs are on 10cm high piers on the rock floor, but the vault is a heavy aluminum streem culvert and a big heat sink, so more heat was needed. I use 220-volt, 50 watt band-style air-conditioner case heaters running on 110v for 25 watts and an indefinite life, and resting on the outside of the steel case, where the mice loved them. For lower wattage and indefinite life, regular 10 watt bulbs can be used in series; we want the heat, not the light, and a burned out bulb can make a very mysterious transient in the data. Strip heaters can be found in surplus stores, and when used in series they don't burn out or burn your hand. Regarding insulation: fiberglass matting gives much greater protection than lighweight styrofoam panels because it has significant thermal mass along with its insulation properties. As Meredith notes, large R-values can be realized with a lightweight plywood box with 4" of fiberglass (or other heavy closed-cell panels) on each side. The more mass in the thermal barrier, the longer the time constant is. To remove the daily thermal noise in 3m deep tiltmeter pits in the Aleutians, we bagged up the volcanic soil and packed it around the sensors, and it reduced the diurnal thermal noise by a factor of 100. So if you can sand-bag your vault ..... or go deeper underground ...! Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: new year Date: Fri, 1 Jan 1999 10:00:12 +1300 Happy new year to all from new zealand i trust that 1999 will bring new challenges and great advances for the PSN and for all in their family lives cheers Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: macsmith Subject: Re: thermal convection in LP sensors Date: Thu, 31 Dec 1998 11:28:39 -1000 For the professionals with budgets, I would have thought that enclosing instruments in a vacuum would eliminate all of theses problems. Has anyone use such things? Happy New Year Ian Smith _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: JIm Hannon Subject: Re: thermal convection in LP sensors Date: Thu, 31 Dec 1998 18:25:07 -0600 macsmith wrote: > For the professionals with budgets, I would have thought that enclosing > instruments in a vacuum would eliminate all of theses problems. > > Has anyone use such things? > > Happy New Year > > Ian Smith > I am busy working on a vacuum enclosed seismograph. There is not too much expense except for the pump to pull the vacuum. But eventhough a vacuum eliminates a lot of problems with convection currents and barometric pressure changes. I suspect that it will have its own set of problems starting with leaks and case flexture. We shall see. Happy New Year -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: KACAMACHO@....... Subject: Re: new year Date: Thu, 31 Dec 1998 20:09:47 EST HAPPY NEW YEAR TO YOU TOO! _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Fred Subject: Re: thermal convection in LP sensors Date: Thu, 31 Dec 1998 17:11:41 -0800 That would be an ideal housing but a fairly expensive undertaking. That would have to be a pretty strong box. If anyone in the bay area wants to try this, I own a pretty good pump that I could loan out. I wonder if the amp's would have to be outside if the tank as the thermal dissapation will be much different. Happy New Year all Fred -- How much choice did God have in constructing the Universe? If the no boundary proposal is correct, he had no freedom at all to choose initial conditions. He would have only had the freedom to choose the laws the universe obeyed. Albert Einstein _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: macsmith Subject: Re: thermal convection in LP sensors Date: Thu, 31 Dec 1998 16:51:05 -1000 I should urge a little caution about using a vacuum. Firstly, one wouldn't use a "box", but a "vacuum vessel", these are usually aluminium, whose walls are 0.25 to 0.5 of an inch thick. Otherwise there is a risk of implosion. Secondly, some vacuum pumps have an exhaust port which has to be vented to the outside, the fumes (evapourated vacuum oil) are poisonous (I can't remember how to spell carsogenic!). One might also think of adding a vacuum guage, to see how good the vacuum is - more expense. All our instruments at the telescopes use these, and we have (working) amps inside, not just at vacuum, but close to Liquid Nitrogen temperature - now there's a thought, low noise amps. Happy New Year. Ian Smith _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Robert Avakian Subject: Re: thermal convection in LP sensors Date: Thu, 31 Dec 1998 21:38:24 -0800 Question. As long as thremal events had periods several times the period of the longest waves, I would think they could be filtered out quite effectively after the fact. So all one would need would be a box which slowed or damped the enviornmental changes effectively. Might a water jacket with a circulating pump be a cheaper and easier alternative to the vacuum scheme? I assume the circulating water could cause a problem, but the pump would not need to run continuously, perhaps several seconds every few minutes? Bob A. macsmith wrote: > > I should urge a little caution about using a vacuum. > > Firstly, one wouldn't use a "box", but a "vacuum vessel", these are usually > aluminium, whose walls are 0.25 to 0.5 of an inch thick. Otherwise there is > a risk of implosion. > > Secondly, some vacuum pumps have an exhaust port which has to be vented to > the outside, the fumes (evapourated vacuum oil) are poisonous (I can't > remember how to spell carsogenic!). > > One might also think of adding a vacuum guage, to see how good the vacuum is > - more expense. > > All our instruments at the telescopes use these, and we have (working) amps > inside, not just at vacuum, but close to Liquid Nitrogen temperature - now > there's a thought, low noise amps. > > Happy New Year. > > Ian Smith > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: evacuated containments Date: Fri, 1 Jan 1999 01:34:00 -0600 (CST) Re vacuum contaiment for seismometers: They have been used since the 50's for high gain long-period sensors, but because these sensors were large (50 cm or more), they were large and dangerous (30" steel tanks), and had serious problems with flexure of the interface between the seis and the pier. But a pressure contaiment for the vertical is necessary to reduce the barometric buoyancy noise by a factor greater than 100. So the current long-period configurations of the major commercial VBB sensors are much smaller, with dimensions within 10 cm, and have isolated bases of Stainless steel or aluminum that are 1 to 2 cm thick, and the covers are coupled to the base with large, often double, O-rings so that flexing of the covers is not transmitted to the base. For barometric noise control, the cover does not have to be evacuated, just vacuum tight. THis however, does not provide thermal control. Most commercial VBB sensors are not evacuated. Even the 1965 gravimeter we are operating to record earth tides is simply sealed in a cylinder of 1/2" plexiglass with double active heaters for stability. (and remote control centering, etc.) The major exception is the STS-1, the cadillac of VBB seismometers, which operates at 360 seconds with a noise level below the low noise earth model. This sensor has a thick Pyrex baseplate that is vacuum-grouted to the pier itself, and a 30cm dia glass bell jar over the sensor for the vacuum. All three components are evacuated, so both barometric and thermal (as well as humidity) control are provided. The vacuum needs to be good, but not "high", like better than 29" of Hg. Recently, the Albuquerque lab has been making a "warpless" baseplate for field re-installation of the STS-1 without the grouted pyrex plates. Photos of such can be found at: http://www.eas.slu.edu/People/STMorrissey/ stmmisc.html PSN INFO ... SLU Seismic Network and a photo of the STS-1s installed on a pier at CCM can be found through: stmiris.html St. Louis Univ. IRIS Broadband Stations I recently re-installed a set of STS-1 at a station near Nashville using the warpless baseplates; I will post the photos when I get them. OTher notes: (repeating some observations by others) 1. Evacuating any container has to be done with great care and a certaity that it will not implode: it should probably be designed for such. Atmospheric pressure on the end of a 12" diameter surface is a total force of 1700 pounds. The container should hold the vacuum indefinitely, since the pump makes vibrations, and a dial vacuum gauge is needed. For the short run of the pump, the vapors are not a problem, no more than automotive oil. While I was working on the cyclotron, we had pumps coating oil vapor on everything, which maybe helped our electrical arcing problems; however, I'm sure that any chance of oil vapor deposition around a telescope is a no-no. 2: Enclosing the seismometer means that the container base has to be rigid enough that it doesn't significantly flex with external pressure changes. To get a feel for the rigidity required, consider a barometric pressure change of 1/2" on the Hg scale of 30" = 1 atmosphere = 15 lbs/square inch. The 1/2" change is about 1/4 lb/sq.in. So if the area is 1 square foot, this is a total change of force of 36 pounds. Suppose (for the discussion), that 1/4 of this is applied just at the center of the side of the box, just like putting a gallon jug of water on it. It should not measurably deflect within the tilt sensitivity of the sensor, usually less than a micron. 3. Once you have your seis in a suitable container, you will need some method to remotely center it, like a small toy motor geared down to a fine threaded rod arranged to move a trim mass along the boom. (The motor itself could be designed to be part of the effective mass; power would have to be minimal to be able to be connected through the fine wires across the hinges). If you even partially evacuate a suitable container, the mass will float down, so remote centering would be a must. 4. You will also need to arrange a vacuum tight method of getting the electrical signals through the wall of the container. A good electronics surplus store might help with connectors. Also, a practical note: If one uses a steel container, like the domed end of a steel tank that I use for vacuum grouting, I have found that a plexiglass porthole or two to allow lighting and viewing the inside of the container can be quite handy. Especially if your "remote centering" consists of a rod through a tight feedthrough that reaches over the boom and allows manual positioning of the centering trim weights. 5. So what am I considering for the next STM design? I need to make it shorter than 11" to get it to fit into a large pressure canner. The canner is all cast aluminum, seals tight, etc. In the mean time, I'm looking at a 20 gallon aquarium with a 1/2" acrilic cover. At the 20 gallon size, some are available with 3/8" thick glass sides and bottoms for lt. $50. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RLLaney@....... Subject: Lehmans and cold weather/thermal convection Date: Fri, 1 Jan 1999 14:52:31 EST Meredith, Greg and Sean-Thomas: I appreciated the notes on your experiences and the suggestions concerning thermal interference. I would love to have a vault and have even considered devoting some garden space to one. But, I have a hunch that I would generate a whole new set of problems for myself. So, I think I will keep the sensors on the garage floor, but will try additional insulation and baffles. Thanks. Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Arie Verveer Subject: Station near you. AutoDRM Date: Sat, 02 Jan 1999 18:56:28 +0800 Hi All, I've just finished writing a "DOS" program that converts the "AutoDRM" waveform files to a file compatible with Winquake. This means you [YOU] have access to over 1,200 professional seismograph channels, World wide. You can request Waveform data from these instruments. If you need to check out that small local event, you now can, via email. Or if you are interested in an event on the other side of the plant and would like to see the original data, you can. See http://www.iinet.net.au/~ajbv/ The test data from Alaska should be "FFT" filtered with a 1.5Hz high pass filter, (Winquake) before you can see the event. I did this to demonstrate that the data from professional seismographs suffer from all the noise problems the PSN community does. Anyhow, this is essentially my first "C" program, so if you find a major bug, please let me know. I hope to eventually locate my local events All the best Arie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Update on Dominica Date: Sat, 02 Jan 1999 12:47:54 -0700 John- Happy Holidays & New Year! We're ... back in the USSA ... Do you have the reference for Dave Hill's paper? -Edward John Lahr wrote: > Hi Wayne, > > One possible source of the noise is the P-phase itself. I was > in the Imperial Valley of California during a swarm of earthquakes > that were shallow and not far away. I could hear them before > I felt them. Some microphones were added to one channel of the > seismic recorders and it was determined that we were hearing the > P-phase and then feeling the S-phase. Dave Hill wrote a paper on > this and showed that the earth was acting like a drum head and > amplifying the vertical motion of the P-phase. > > The earthquakes sounded like thunder in the distance. > > If people are hearing events now, but they did not hear them > in the past, this could be due to a change in earthquake location, > magnitude, or focal mechanism. > > JCLahr > ################################## John C. Lahr > ################################# Seismologist > ################################ U.S. Geological Survey > ############################### Geologic Hazards Team, MS966 > ############################## PO Box 25046 > #############################/############################## > ############################/############################### > Denver, Colorado 80225-0046 ################################ > Phone: (303) 273-8596 ################################## > Fax: (303) 273-8600 ################################### > lahr@........ ##################################### > http://giseis.alaska.edu/lahr > http://lahr.org/john-jan > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Station near you. AutoDRM Date: Sat, 02 Jan 1999 18:12:03 -0700 (MST) On Sat, 2 Jan 1999, Arie Verveer wrote: > Hi All, I've just finished writing a "DOS" program that converts the "AutoDRM" > waveform files to a file compatible with Winquake. Arie, What is the difference between AutoDRM files and SAC files? I usually use the latter, so I haven't come across this file type. Who is using it? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Arie Verveer Subject: Re: Station near you. AutoDRM Date: Sun, 03 Jan 1999 10:48:48 +0800 Hi John John Hernlund wrote: > > What is the difference between AutoDRM files and SAC files? I usually use > the latter, so I haven't come across this file type. Who is using it? > It appears that "AutoDRM" outputs are given in plain text while SAC outputs are in binary(?). I assume that the plain text is given, so as to cover all possible types of data transfer. There is a good smattering of countries around the world that use AutoDRM and each of these have many professional stations connected to them. Most likely they give there outputs in SAC and AutoDRM and whatever form, the profession geophysical community needs. The good thing for a PSN user is that we can get very, nearly real time waveform data from all over the world. In Western Australia this sort of data access is marvellous, I can now confirm any possible local events. Normally I had to wait until the middle of the next month before the states Geophysical Centre would publish there findings. But since that centre is going to close down in about a year, that will be it, no more data. The seismic stations are going to be controlled from the eastern side of the country. The AutoDRM site. All the best Arie See http://www.iinet.net.au/~ajbv/ if you are interested. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Arie Verveer Subject: Update: Station near you. AutoDRM Date: Sun, 03 Jan 1999 13:32:25 +0800 Hi All, Sorry about this, but it turns out that if you have multiple requests in a AutoDrm request and the station name stays the same then the program "GSEtoPSN.exe" will overnight file name with next decoded data block. I've now fixed this, by making the extension the same as the channel name. I've latest software is at. http://www.iinet.net.au/~ajbv/ Oh well.......... Arie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Mark Robinson" Subject: New Zealand event and links to IGNS Date: Sun, 3 Jan 1999 21:20:50 +1300 Hi folks A couple of related events near Wellington today. 4.2 and 5.1. see http://www.gns.cri.nz/news/earthquakes/latest_drum.html http://www.gns.cri.nz/news/earthquakes/recent_quakes.html regards Mark G Robinson | ZL2TOD | other@............... Box 8770, Auckland 1035, New Zealand Phone +64-9-846-3296 | Fax +64-9-849-7408 ------------------------------------------------ 03 Jan 1867 Te Whiti released from prison in the South island. 03 Jan 1959 Alaska becomes the 49th state of the U.S.A. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: Capacitors Date: Sun, 03 Jan 1999 09:51:24 -0800 Brett & Fred Thanks for your capacitor input. I haven't checked your links yet Brett. I have been using Don Lancaster's Active filter cookbook to design my instrument filtering. I just went from a 4 pole Butterworth lowpass(10 hz) to a 6 pole. I now seem to be getting more periods of 10 hz oscillations. I guess they are triggered by transient input or/and low damping? They are configured similar to Larry's board but with different values. Currently all the caps are equal (0.15u) . To all: Would decreasing the feedback cap slightly reduce the oscillations? Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: macsmith Subject: Pacific Rim Quakes Date: Sun, 03 Jan 1999 08:12:02 -1000 here's an interesting news report on the recent Pacific rim quakes: http://www.news.bbc.co.uk/hi/english/world/asia-pacific/newsid_247000/247363.stm _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: VBB and filters Date: Sun, 3 Jan 1999 14:04:57 -0600 (CST) Barry, I am uncertain where you are using the filter, why, or why you seem to have an undamped response. As I recall, you are using the latest triple feedback VBB configuration, as used for the STS-1, the Guralps, and the STM-8. I justed looked at the transfer function I have here for your 6" design, based on some of the parameters you sent some time ago. It has an r = 234 000 V/m/sec. G=12.65 N/A; M=0.35kg; Cp=24uf; Rp=1 meg ohm; RI=0.107 meg ohm, and Ti= 80 seconds. and To = 1.7 seconds. ... and looks like it should be quite stable, with Tn = 90 seconds. (most of the numbers are defaults from the STM-8; you can update them). It is important to know the sensitivity of your displacement transducer to properly use the Mathcad model of the transfer function. The resulting response quite accurately reflects what you get, as I have previously shown in the calibration data. The transfer function will indicate an oscillator if either end of the flat velocity response has an inflection in it. If the damping term zeta is much less than 0.6, the oscillation will be at the effective period, like 20 to 100 seconds, depending on your configuration. If the response has a bump at the short period end, several instabilities are possible due to "out of range" selection of the feedback components, like the value of Cp is too large or r is too small or too large. The response should be quite flat. The usual cause of oscillation or ringing is because r is too large. As Brett's effort shows, there is little in the loop to damp the high-end oscillation if the loop has the gain to oscillate there. To determine the actual value of r, the gain(s) of the displacement amplifier(s) need to be known; this is readily determined from the elements in their feedback per your schematic. Like for one of the VBBs here, the transducer is 58mv/micron, the first amp is x3, the second is x10, so the value used in the Mathcad function (which uses MKS units) is 1 740 000 volts/meter. (1.74 million V/m sounds hugh, but it is a reality of the VBB). My old transfer function response indicates an oscillation at 300-400hz, which I can hear, but I killed it with appropriate low-pass filtering (a larger feedback capacitor) in the 2nd X10 displacement amp. To control (= live with) local cultural noise (= the street) I use 2-pole filters at 2 hz (or so) in the line driver amplifier, which is a high-pass (1000 second) output of the VBB signal. These are outside the loop, so only affect the "cosmetic" appearance of the data, reducing the local noise so I can see microseisms and teleseisms. So determining their parameters is mostly a trial and error activity. Lancaster's book is a good resource; it shows different damping options for the filters on pages 75-77; you might want to use what he calls the "compromise" between best delay and flattest response, which is (referring to the NASA Active filter Design Handbook (SP-5104; 1977), a "Legendre" response, somewhat between a Bessel and a Butterworth response. Anything with ripple in the passband (the Chebyshev filter) will have a sharper cutoff, but will ring in response to an impulse. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: VBB and filters Date: Sun, 03 Jan 1999 13:24:23 -0800 Hi Sean Thomas Thanks for your response. I'll spend some time reviewing the content. I'm not having a problem with the VBB, it's with the Lehman when it comes into the house. The sensor is in the garage (~50 ' away) and when it comes in on a shielded cable I filter it with a 6 pole low pass. The circuit inside was a 30k load resistor followed by a noninverting 10X preamp, 6 pole butterworth, 1 pole 0.008 hz highpass, 18X amp, and 10 hz single pole lowpass, and computer. I put a single pole 10hz low pass just as the cable comes into the house and it seems to help. I have more problems during the day, probably traffic. On a separate subject, I finally ordered some parts from digikey to take my VBB off the solderless bread board. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Marchal van Lare Subject: TEST - please IGNORE Date: Sun, 3 Jan 1999 17:07:18 -0500 TEST= _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RADIOTEL@....... Subject: LEHMAN RESPONSE Date: Sun, 3 Jan 1999 23:22:42 EST Any List members I have just finished a Lehman seismograph, placed it in a plywood enclosure with form insulation on sides and top and a 10 watt light bulb. The seis is sitting on a cement slab that about 6 X 3 Feet and 4 inches deep. I am temporarily using a tupper-ware bowl filled with brake fluid to dampen the boom. I have the seis connected to an amp with about 1800 gain and a 15Hz filter. Watching the trace on the screen, there is a slow undulation wave pattern (almost straight across the screen). My problem (at least I assume it is a problem) is when I walk on the ground around the seis it generates a very large undulating wave pattern going off the screen and slowly returning until it finally returns to the wave pattern where it was before detection. I have tried minimum damping and maximum damping. Based on a geophone that I installed recently I assume this wave pattern is not normal. The geophone has essentially a straight wave pattern until detection and then the wave is closely spaced in the traditional pattern routinely seen from other. Thanks Jim Allen _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: meredith lamb Subject: Re: LEHMAN RESPONSE Date: Sun, 03 Jan 1999 23:14:10 -0700 RADIOTEL@....... wrote: > My problem (at least I assume it is a problem) is when I walk on the ground > around the seis it generates a very large undulating wave pattern going off > the screen and slowly returning until it finally returns to the wave pattern > where it was before detection. I have tried minimum damping and maximum > damping. Based on a geophone that I installed recently I assume this wave > pattern is not normal. The geophone has essentially a straight wave pattern > until detection and then the wave is closely spaced in the traditional pattern > routinely seen from other. > Thanks > Jim Allen > Jim, What is the period of the undulations? Could be long period microseisms....mine in Denver are running roughly 6-8 seconds. Regardless......congratulations on building the seismo......hope future adjustments improve it to your satisfaction. Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: meredith lamb Subject: Re: LEHMAN RESPONSE Date: Sun, 03 Jan 1999 23:29:01 -0700 Jim, Forgot to add.....of course walking around a seismo will make it tilt.....that is normal. With time you will recognize all the floor and car and etc., tilting "noise" as such. What you get out of the total system without inducing tilt is what counts. You should see activity all the time with the gain high enough....adjust it to the least gain, but, enough to see some activity most of the time on the computer screen. Then......you can adjust the damping oil levels. Damping with oil I've never done, but I suppose the only way is alot of experimentation....filling, lowering. It could be that you may need alot more fluid than you've already tried. Again.....Congratulations. Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: 2 M5+ New Zealand events Date: Mon, 4 Jan 1999 22:12:57 +1300 for those of u not on the PSN events list some info on the 2 recent NZ events........ M5.7 Near Rotorua upper central Nth Is NZ 144 km deep on the subducting slab under the volcanic zone M5.4 NW of Wellington City Sthrn end of the Nth Island (epic in Cook Strait) this 54 km deep event is also part of the subduction zone but at its southern end this region around cook strait has very complex tectonics as its the boundary between the subduction zone under and to the north of the Nth Island and the oblique slip zone in the south island that has thrust up the southern alps. the oblique slip Alpine Fault has a 3:1 ratio for every 3 metres of horizontal movement there is 1 metre of vertical movement. The subduction under the North Island is ~ 40 mm (4 cm 2 odd inches / yr) the convergence of the pacific plate against the indo-australian plate along the South Is's Alpine Fault is ~ 30 mm (3 cm 1.25 " / yr) Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: robert barns <75612.2635@..............> Subject: LEHMAN RESPONSE Date: Mon, 4 Jan 1999 10:36:16 -0500 Jim Allen, My Lehman behaves pretty much as you describe. It sits on the concrete= floor of my basement. If I walk within 5 feet of it, I see a fairly larg= e signal. Within 2 feet, it goes off scale. A Lehman is very sensitive to tilt and these signals are undoubtedly du= e to bending of the concrete floor. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Norman Davis WB6SHI Subject: Re: LEHMAN RESPONSE Date: Mon, 04 Jan 1999 08:03:55 .. > A Lehman is very sensitive to tilt and these signals are undoubtedly due >to bending of the concrete floor. >Bob Barns I'll drink to that. I had mine in the back of the garage. On the outside is sat on a slab that had been poured around the outside like a sidewalk. Whenever the ground got wet and swelled the slab would tilt and eather bottom out the lehman or run it out of the coil. I moved it into the garage and that stoped that. Next project... Slab buy it self away from the whole house and garage. Norman Davis WB6SHI Shingle Springs, Ca normd@............. http://www.directcon.net/normd/index.htm _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Lahr Subject: Re: Update on Dominica Date: Mon, 4 Jan 1999 12:58:27 -0700 (MST) Hi Ed, Welcome back! The Hill reference is: BSSA, August 1976, v 66, pg 1159-1172. John _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: Lehman tilt sensitivity Date: Mon, 4 Jan 1999 14:31:55 -0600 (CST) Jim, Congratulations! Some thoughts on your Lehman horizontal seismometer: (I have edited together some previously posted information; you may already have seen this) The Lehman is a "real-world-boys'" version of the Columbia-Sprengnether S5000 long-period, of which there are over 1000 in use; Meredith has a set; but I think there are others out there in the PSN. I have scanned a pictorial drawing of it to my web site on the psn info page. http://www.eas.slu.edu/People/STMorrissey/ stmmisc.html Some formulae of interest for the horizontal pendulum: (assuming that the restoring force by the hinges and/or pivot are minimal): The natural period: Tn = 2*pi*sqrt(l/(g*sine i)) where l is the boom length in cm, g=980cm/sec^2, i is the angle that the boom makes wrt the horizontal, measured in radians, (where sine i = i). For example, a 40 cm boom hanging vertically as a simple pendulum ( an angle of 90 degrees) has a period of 1.3 seconds, likr a SG. (a one second clock pendulum is 24.8 cm). When tilted horizontally to about 4 degrees, the period is 5 seconds. At about a 1 degree angle (sine i = 360deg/(2*pi) ), it is 10 seconds, and at about 0.23 deg. it is 20 seconds. So the period is changing with inverse of the square root of the angle, which is why long periods are so unstable. But unstable also means sensitive to smaller ground motions, which is why geophones fall short for LP sensitivity. So the stability question for a horizontal seismometer depends mostly on the mechanical period and the working range of the velocity coil; ie how far it can drift before touching. The old S5000s that I operate at 15 seconds in vaults rarely need to be recentered. (the working range is +,- 5mm for these horizontals). Years ago we ran them at 30 seconds, and had to center them about every other month. I understand that most Lehmans operate at 10 seconds give or take, but that some can be workable at 20 seconds with more frequent adjustment. Of course, the quality of the base, the rigidity of the boom support, and the stability of the pier then become a major concerns. Also, thermal effects on the base and frame of the instrument can cause major drifting. I don't have any information on the actual sensitivity of the Lehman designs that are in use. But for comparison to the S5000s I am operating at 15 seconds, which have a 32 tpi (turns per inch) leveling screw, about 1/100th turn (the leveling knob happens to have about a 100 mm circumference) is about 16 microradians, and moves the mass about 1mm. One can calculate how much the mass should move when tilted at a given period. This is a useful calculation for the tilt sensitivity of the horizontal pendulum (which can be used to calibrate the displacement detector) z = (g * Tn^2 / 4 * pi^2) * phi where z is the horizontal displacement of the mass, Tn is the natural period, and phi is the tilt of the base at right angles to the boom, again measured in radians. From my example above about the S5100: the base is 500 mm, so the tilt from 1/100 turn of the screw ( which is 0.008 mm) is 0.008/500 = 0.000016 radian. If Tn = 15 seconds, the mass will move 0.88 mm, which is close to my approximation. Evaluating this on my STM-8 horizontal, with l = 40 cm, and Tn = 10 seconds, 1/12 turn of the 28 tpi leveling screw is 0.9mm/12 = 0.075mm; the base width is 130mm, so the tilt is 0.075/130 = 0.00058 radians. This calculates to an offset of the mass of 1.43 cm, which is about what I measure. At 20 seconds, the offset is about 4 times, or 5.7 cm. Two points are clear: the stability is inversely proportional to the square of the period, or conversely, the sensitivity increases with square of the period. And the amount of the mass is not a consideration for the period or the displacement sensitivity. As long as it is significantly greater (like 10x) than the weight of the boom, it will work. And a final thought: I would forgo the hydraulic damping and simply use resistive damping with the main coil by shunting it with an appropriate resistor, which is what is done in modern seismology. The value of the resistor can be readily calculated; the voltage loss of the resistive damping is easily made up for with additional gain of the preamplifier. You can also add a separate moving coil/ magnet to accomplish the damping. Some LP high-gain sensors have a 100 000 ohm signal coil, which won't pass enough current to damp the seis, and a standard 500 ohm coil, for which the damping is calculated. For your fconvenience, I will re-post the formulas for calculating damping with a moving coil. One last note: since the LP horizontal IS so tilt sensitive, and will wander off scale at most "practical" sites, one could consider using a single high-pass filter at the input to the recording amplifier, like 1000 uf with 1 megohm, which will remove the long period drift that even a moving (velocity) coil will produce, and allow higher gains in the 1 to 20 second range. regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: Lehman damping Date: Mon, 4 Jan 1999 14:33:14 -0600 (CST) Here is an edited repeat of a previous mote about damping seismometers: Re electromagnetic damping: Most moving coil seismometers only use resistive damping. If properly calculated, no other damping is needed or should be used. Damping is generally expressed in relation to what is needed for "critical" damping, which means that after a step input, the output returns to a zero output voltage as rapidly as possible without overshooting. This damping has a value of 1. But it has a price, namely significant loss of the signal in the damping resistor. So generally damping is set at 0.8 of critical, which cuts the loss by about half, but the overshoot to an impulse input is minimal. Much less than 0.8, the natural period of the seismometer will dominate the response. On the other hand, if a fairly broad response is desired, and the seis and the amplifier have enough output and/or gain, damping as high as 2 can be used. Note that actually calculating the proper resistor depends on how much you know about the geophone or seismometer. The manufacturers data will sometimes even give the value for critical damping. But if the geophone is a mystery device, a generally good approximation is to measure the resistance of the coil and use that value for the damping resistor. To calculate the value of the damping resistor to be used, one first has to know or determine the open circuit damping, called Bo. It is the mechanical air-dashpot function of the coil movement, and is often listed in the specifications for the seismometer. For most seismometers, it ranges from 0.2 to 0.4, where a value of 0.8 is for critical damping. It can also be determined from the logrithmic decrement of the free oscillations of the undamped seismometer. (write for details on logrithmic decrement; you need a recorder or oscilloscope to do it. It involves measuring the successive amplitudes of undamped oscillations). Then the motor constant and resistance of the main coil have to be determined or found in the specifications. The electromagnetic damping Bem needed is determined by subtracting the Bo from the required total Bt. Bem = Bt - Bo (If you don't know your Bo, use a value of 0.3) Then the damping resistor is calculated by: Bem = G^2 / (2*omega*M*(Rs + Rd), or Rd = [G^2 / (Bem*2*omega*m)] - Rs Where Bem is the electromagnetic damping, G is the main coil constant, omega is the angular frequency, equivalent to 2*pi/Tn, where Tn is the natural period, and M is the mass. For an L4-C, with a 5500 ohm coil, with G = 270 V/m/sec, Bo = 0.27, we want Bt to be 0.77, so Bem = 0.5, M = 1 kgm, omega = 2*pi, we calculate a damping resistor Rd of 6102 ohms for critical damping. For an S5000 Long Period Seis, with a 500 ohm coil, G = 100 V/m/sec, Bo = 0.1, we want a flatter response with Bt = 1, so Bem = 0.9, omega = 2*pi/15 (seconds), M = 11 kg, we calculate a resistor of 705 ohms for Bt = 1 (the LP is over damped for a broader response). For an HS-1 4.5 hz geophone with a 1250 ohm coil, G = 41 V/m/sec, and Bo = 0.28; we want critical damping with Bt = 0.8, so Bem = 0.52, omega = 2*pi*4.5 (hz), M = 0.022kg, we calculate Rd = 1348 ohms. This method of damping is the only method currently being used on velocity sensors. The method is so exact that often the resistor for Rd is installed inside the smaller geophones at the factory. Metal-film resistors are used for lower noise. When one is connecting a seismometer to an amplifier with a low input impedance Ra, that value is in parallel with the seismometer, so must be taken into account. So if Ra = 10k ohms, and Rd is to be 5k ohms, the actual resistor to be used is Rs = Rd*Ra/(Ra-Rd), or in this case Rs = 10k ohms. Generally very high input impedance amplifiers are not used because of noise considerations, so this detail is often overlooked. Unfortunately I have no idea what the constants for a Lehman might be. I note that the coil is 1/4 pound of # 34 wire which has 8310 feet per pound and 2168 ohms per pound at 20 deg.C. So assuming the coil is about 500 ohms, I would try a damping resistor of about 1000 ohms, unless you already know the constant G of the main coil and can calculate the value. With this type of damping, the response should be flat to velocity from roughly the natural period to whatever low-pass filter you have in your amplifier. (BTW another place to check to see if the shorter p-wave phases are being filtered out). The drawback of resistive damping, other than the loss of part of the signal from the coil (made up for with less attenuation in the recording circuitry) is that it is dissipative, and makes noise. This is the reason it is not used in the VBB configuration, where the damping is a dynamic process in the feedback loop. The noise from the damping resistor is primarily Johnson or thermal noise, which can be estimated, as well as 1/f noise. A low noise metal film resistor does help. This noise is generally not a problem for most seismometer sites. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RADIOTEL@....... Subject: Re: Lehman tilt sensitivity Date: Mon, 4 Jan 1999 23:29:25 EST Meredith, Norman,Bob and Sean-Thomas Your suggestions and experiences that you shared were very helpful. I had not realized that the lehman would be so sensitive (even showing those microseisms). Next weekend I will connect a varible resistor (10 turn 0 -30k variable wire-wound resistor) across the coil which is 9.7k. That certainly should dampen it adequately (if I am reading the formulas given in Sean- Thomas' response, right? I will also follow the recommendation by Sean-Thamas to use a high pass filter to help remove the long period drift. Jim Allen radiotel@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Francesco" Subject: R: Station near you. AutoDRM Date: Tue, 5 Jan 1999 12:37:09 +0100 Hello Arie. I had download your C programm for AUTODRM, but I'haven't understand a = thing. I have required a file to PIDC ORG for example. I have received the = mail, with inserted the file in GSE2.0 format, but not attached. =20 This way, I have a file of mail (uencode, ecc.ecc.) but not a named file = available to convert with your program. =20 How do I have to do? =20 Regards Francesco Nucera - I.ES.N. PSN ITALY
Hello Arie.
I had download your C programm for = AUTODRM, but=20 I'haven't understand  a thing.
 
I have required a file to PIDC ORG = for example.=20 I have received the mail, with inserted the file in GSE2.0 format, but = not=20 attached. 
This way, I have a file of mail (uencode, ecc.ecc.) = but not=20 a named file available to convert with your program. 
How do I = have to=20 do? 
Regards
 
Francesco Nucera -  = I.ES.N.  PSN=20 ITALY
From: Arie Verveer Subject: Re: R: Station near you. AutoDRM Date: Tue, 05 Jan 1999 21:23:02 +0800 Hi Francesco > I had download your C programm for AUTODRM, but I'haven't understand a thing.I have required > a file to PIDC ORG for example. I have received the mail, with inserted the file in GSE2.0 > format, but not attached. > This way, I have a file of mail (uencode, ecc.ecc.) but not a named file available to convert > with your program. > How do I have to do? If your mail program has an edit feature then you could open the AutoDRM message, mark the text, and then go to your edit menu and press the copy option. Then go to a text editor and paste the document. Then you should be able to save the data as a file. This may be one solution. Are you running Eudora lite ? I do understand its a strange way to get data but once you master the technique its really worth it. This is especially true when you are in an area where data is hard to get. If you have any more troubles please let me know. Its worth persevering with the AutoDRM, especially the method of getting the data. All the best, a please let me know how it worked out. Arie Today I used the AutoDRM to confirm a small event as coming from a mining area 140km from my station. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RADIOTEL@....... Subject: LEHMAN RESPONSE Date: Tue, 5 Jan 1999 22:13:31 EST Meredith, Norman, Bob and Sean-Thomas My new lehman picked up its first earthquake today. Meridith,Norman and Bob's suggestions that the undulations and tilt were normal was correct. I did need more damping as Meridith suggested and I took Sean-Thomas' suggestion to get rid of the oil damping. The installation of resistive damping made a world of difference especially using a variable resistor which I can adjust from inside the house while the seismo is outside. When I dont get near the seismo I now find that the wave trace is essentially straight. Next weekend I plan to add a 1000 uf cap and 1 meg res. filter to the amp input to ensure that drift will be minimal. Your help and encouragement was invaluable. Jim Allen radiotel@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Arie Verveer Subject: Year 2000 Calendar Date: Wed, 06 Jan 1999 14:21:50 +0800 Hi All, I was looking up some information on the year 2000 calendar dates when I came across this interesting bit information. The years 1876, 1944, 1972, 2000, 2028 all have the identical calendar. The 1st of those years all start on a saturday and years following are in the calendar sequence. So just set your old computer clock to -28 years and all will be well? Just remember to add 28 years. Just an observation. - Arie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 07:51:35 -0400 Arie I thought the calendar repeated itself every 11 years. Wayne Arie Verveer wrote: > Hi All, > I was looking up some information on the year 2000 calendar dates > when I came across this interesting bit information. > > The years 1876, 1944, 1972, 2000, 2028 all have the identical calendar. > The 1st of those years all start on a saturday and years following are in the > calendar sequence. > So just set your old computer clock to -28 years and all will be well? > Just remember to add 28 years. > > Just an observation. - Arie > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 09:25:58 -0500 Arie, I may be way wrong, but I thought, unlike the other four years you mention, that 2000 is *not* going to be a leap year. Does anyone remember for sure? Brett At 02:21 PM 1/6/99 +0800, you wrote: >Hi All, >I was looking up some information on the year 2000 calendar dates >when I came across this interesting bit information. > >The years 1876, 1944, 1972, 2000, 2028 all have the identical calendar. >The 1st of those years all start on a saturday and years following are in the >calendar sequence. >So just set your old computer clock to -28 years and all will be well? >Just remember to add 28 years. > >Just an observation. - Arie > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: bc Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 09:49:42 -0500 At 09:25 AM 1/6/99 -0500, you wrote: >Arie, > >I may be way wrong, but I thought, unlike the other four years you mention, >that 2000 is *not* going to be a leap year. Does anyone remember for sure? > >Brett Typically century marks are not leap years. I'm not absolutely sure about 1000 year marks but i don't remember them being treated special so my best educated guess is that it is not a leap year. However, I'm not sure I'm actually following this thread? Is it the contention that by advancing one's date to the year 2028 that we will avoid a year 2000 problem? If that's the assumption than I'm afraid its incorrect. If not, my apologies for sticking my nose in where it doesn't belong (a bad habit I seem to have) bc > > >At 02:21 PM 1/6/99 +0800, you wrote: >>Hi All, >>I was looking up some information on the year 2000 calendar dates >>when I came across this interesting bit information. >> >>The years 1876, 1944, 1972, 2000, 2028 all have the identical calendar. >>The 1st of those years all start on a saturday and years following are in the >>calendar sequence. >>So just set your old computer clock to -28 years and all will be well? >>Just remember to add 28 years. >> >>Just an observation. - Arie >> >> >> >>_____________________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email listserver@.............. with the body of the >>message: leave PSN-L > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: bzimmerman@............ Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 09:59:03 -0500 (EST) The calender on my desk shows 29 days in February 2000. Brian Zimmerman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: bc Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 10:19:47 -0500 At 09:59 AM 1/6/99 -0500, you wrote: > >The calender on my desk shows 29 days in February 2000. > >Brian Zimmerman I stand corrected on 2 counts. First, I understand the thread now. Its to correct OLD calendar clock systems to just get the correct day of the week. Second, it is a leap year. The following is from Leap Year FAQ at http://aa.usno.navy.mil/AA/faq/docs/faq1.html The Rule According to the Gregorian calendar, which is the civil calendar in use today, years evenly divisible by 4 are leap years, with the exception of centurial years that are not evenly divisible by 400. Therefore, the years 1700, 1800, 1900 and 2100 are not leap years, but 1600, 2000, and 2400 are leap years bc _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Canie Brooks Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 08:29:22 -0800 At 09:25 AM 1/6/99 -0500, Brett Nordgren wrote: >Arie, > >I may be way wrong, but I thought, unlike the other four years you mention, >that 2000 is *not* going to be a leap year. Does anyone remember for sure? > >Brett I'll also add my 2 cents worth - I'm a programmer and this is one of the issues creating part of the 'millenium bug' ! The year 2000 IS a leap year and lots of programs, operating systems don't recognise it as such.. One of the big things to fix... Canie > > >At 02:21 PM 1/6/99 +0800, you wrote: >>Hi All, >>I was looking up some information on the year 2000 calendar dates >>when I came across this interesting bit information. >> >>The years 1876, 1944, 1972, 2000, 2028 all have the identical calendar. >>The 1st of those years all start on a saturday and years following are in the >>calendar sequence. >>So just set your old computer clock to -28 years and all will be well? >>Just remember to add 28 years. >> >>Just an observation. - Arie >> >> >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: [Fwd: MessageShip Response to MSG_ID=All] Date: Wed, 06 Jan 1999 15:46:54 -0400 Arie This is a message I received when I tried a request from autodrm. Just thought I would pass it on. Wayne From: John Hernlund Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 12:56:44 -0700 (MST) On Wed, 6 Jan 1999, bc wrote: > At 09:25 AM 1/6/99 -0500, you wrote: > >I may be way wrong, but I thought, unlike the other four years you mention, > >that 2000 is *not* going to be a leap year. Does anyone remember for sure? > >Brett > Typically century marks are not leap years. I'm not absolutely sure about > 1000 year marks but i don't remember them being treated special so my best > educated guess is that it is not a leap year. However, I'm not sure I'm > actually following this thread? Is it the contention that by advancing > one's date to the year 2028 that we will avoid a year 2000 problem? If > that's the assumption than I'm afraid its incorrect. If not, my apologies > for sticking my nose in where it doesn't belong (a bad habit I seem to > have) I think the only rule for leap years is an extra day in February (the 29th) every four years. This is because the year is approximately 365 and 1/4 days long. I think we also have leap seconds every year, but I am not sure if that is just rumor or truth... For those using WWV though, these leap seconds could be a hassle; that is, if they exist. Also, the only thing special anyone is doing for 2000 that I have heard about is going to Jerusalem and vowing to die in a violent fight to prepare the way for the second coming... I have a feeling that this type of thing will be a problem for governments worldwide this year... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: [Fwd: MessageShip Response to MSG_ID=All] Date: Wed, 06 Jan 1999 13:27:53 -0700 Wayne Abraham J73WA wrote: > This is a message I received when I tried a request from autodrm. Just > thought I would pass it on. I'm not Arie, but I'm guessing you wanted the binary file sent to you directly? If so it's possible you requested it wrong. It looks like the server put it on a FTP server for you to download. From what it says, try this: ftp into pidc.org username anonymous with an email address for the password cd to /pub get 5264365.msg.Z Then you gotta get tar for DOS unless you have Linux or Solaris or something. The Z means the file is compressed. Check out gnu.org if you need it. It's probably in lots of other places also. It is there. I just checked. Good luck, Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 13:34:48 -0700 John Hernlund wrote: > long. I think we also have leap seconds every year, but I am not sure if that > is just rumor or truth... For those using WWV though, these leap seconds > could be a hassle; that is, if they exist. I found this just now: http://www.dtic.mil/doctrine/jel/doddict/data/l/03463.html "Leap Second (DOD) A second of time that is added to or removed from Coordinated Universal Time (UTC) to keep UTC within 0.9 seconds of UT1 (see Universal Time). Leap Seconds are normally introduced at the end of June or December if required. The decision to introduce a Leap Second is announced by the International Time Bureau (Bureau International de l'Heure, or BIH) approximately eight to ten weeks in advance. See also Coordinated Universal Time." Neat little military biased dictionary. I remember hearing other people talking about adding them at one of my former jobs. I've never been involved myself. I would think that WWV would handle this pretty much automatically. Same for GPS. It might take a full minute or two for the computer to catch up to the signal time though. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Subject: Re: Year 2000 Calendar Date: Wed, 6 Jan 1999 14:49:38 -0600 (EST) See http://tycho.usno.navy.mil/leapsec.html for a detailed description of the leap second and how it affects GPS wwV etc. Jim Hannon http://soli.inav.net~jmhannon/ 42,11.90N,91,39.26W WB0TXL On Wed, 6 Jan 1999, Greg wrote: > John Hernlund wrote: > > > long. I think we also have leap seconds every year, but I am not sure if that > > is just rumor or truth... For those using WWV though, these leap seconds > > could be a hassle; that is, if they exist. > > I found this just now: > http://www.dtic.mil/doctrine/jel/doddict/data/l/03463.html > > "Leap Second > > (DOD) A second of time that is added to or removed from Coordinated > Universal Time (UTC) to keep UTC within 0.9 seconds of UT1 (see > Universal Time). Leap Seconds are normally introduced at the end of June > or December if required. The decision to introduce a Leap Second is > announced by the International Time Bureau (Bureau International de > l'Heure, or BIH) approximately eight to ten weeks in advance. See also > Coordinated Universal Time." > > Neat little military biased dictionary. I remember hearing other people > talking about adding them at one of my former jobs. I've never been > involved myself. > > I would think that WWV would handle this pretty much automatically. Same > for GPS. It might take a full minute or two for the computer to catch up > to the signal time though. > > ,Greg > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 14:14:31 -0700 jmhannon@............. wrote: > > See http://tycho.usno.navy.mil/leapsec.html for a detailed description of > the leap second and how it affects GPS wwV etc. That page mentions that GPS is not corrected for some reason, but it doesn't mention WWV. I did find that also. WWV is corrected (I hope that is correct) ;) GPS is off by about 13 seconds right now. http://www.bldrdoc.gov/timefreq/pubs/sp432/s_appa.htm What time is it? ;) ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Kevin J. Rowett" Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 13:32:45 -0800 >I would think that WWV would handle this pretty much automatically. Same >for GPS. It might take a full minute or two for the computer to catch up >to the signal time though. WWV distributes time on the UTC scale, which includes leap second insertions. GPS time is not on the UTC scale because it doesn't insert any (more) leap seconds. The GPS messages do contain both an indication that a leap second will be inserted into the UTC scale at the end of the month, and how many have been inserted so far. This allows a GPS receiver to produce a pretty accurate estimate of UTC directly. I noted any more leap seconds because when GPS time was first synchronized in 1980, 19 leap seconds were already inserted, and GPS included those. So GPS time is now 13 seconds ahead of UTC. KR _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 14:40:06 -0700 "Kevin J. Rowett" wrote: > So GPS time is now 13 seconds ahead of UTC. Larry C., is SDR using the offset in it's time with your GPS reciever? It would probably be pretty obvious if it's not. It would be kinda fun to watch it handle the leap second as it happens, if it does look at that. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Kevin J. Rowett" Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 14:04:37 -0800 At 01:40 PM 1/6/99 , you wrote: >"Kevin J. Rowett" wrote: > >> So GPS time is now 13 seconds ahead of UTC. > >Larry C., is SDR using the offset in it's time with your GPS reciever? >It would probably be pretty obvious if it's not. It would be kinda fun >to watch it handle the leap second as it happens, if it does look at >that. It was fun, especially since the USNO clock 'tick.usno.navy.mil' didn't update properly (tick did, clepsydra.dec.com didn't). BTW, the proscribed insertion method is to duplicate the last second of the month, hence the leap second was in 1998, *not* 1999. Some clocks will display 23:59:59 23:59:59 24:00:00. Some display the dup :59 as :60. You'll have to wait 17 months and a few days now to see the next one mostly likely. Check with IERS in July. KR _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 14:05:22 -0800 At 02:40 PM 1/6/99 -0700, you wrote: >"Kevin J. Rowett" wrote: > >> So GPS time is now 13 seconds ahead of UTC. > >Larry C., is SDR using the offset in it's time with your GPS reciever? >It would probably be pretty obvious if it's not. It would be kinda fun >to watch it handle the leap second as it happens, if it does look at >that. > >,Greg When I added the GPS support too SDR I didn't notice a 13 second offset problem, so the ONCORE GPS receiver must be handling this.... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Kevin J. Rowett" Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 15:23:48 -0800 >>> So GPS time is now 13 seconds ahead of UTC. >> >>Larry C., is SDR using the offset in it's time with your GPS reciever? >>It would probably be pretty obvious if it's not. It would be kinda fun >>to watch it handle the leap second as it happens, if it does look at >>that. >> >>,Greg > >When I added the GPS support too SDR I didn't notice a 13 second offset >problem, so the ONCORE GPS receiver must be handling this.... It does, as long as it has satt lock, and the ephemeris acquired during the leap second event. Most GPS receivers output time (the PVT message) on the UTC scale. You have to fiddle with them in propietary ways to get them to output the true GPS time. KR _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 16:47:05 -0700 (MST) On Wed, 6 Jan 1999, Kevin J. Rowett wrote: > So GPS time is now 13 seconds ahead of UTC. I wonder what happens to files that are archived from seismograph stations receiving GPS time correction then, are they all normalized to UTC after retrieving the data??? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Kevin J. Rowett" Subject: Re: Year 2000 Calendar Date: Wed, 06 Jan 1999 16:05:56 -0800 At 03:47 PM 1/6/99 , you wrote: >On Wed, 6 Jan 1999, Kevin J. Rowett wrote: >> So GPS time is now 13 seconds ahead of UTC. > > I wonder what happens to files that are archived from seismograph stations >receiving GPS time correction then, are they all normalized to UTC after >retrieving the data??? I think some confusion exists here. GPS receivers normally issue time messages (the PVT message) using the UTC scale, which includes leap seconds. The time "flowing down" from the satt is on the GPS time scale which doesn't include leap seconds past 1980. The receiver "subtracts" the number of leap seconds (it's a lot more complicated than this, read the GPS spec!) presently indicated in the difference between UTC and GPS time. As Larry noted, his use of the Moto oncore GPS receiver is the normal one -> UTC time scale. The original point was WWV and GPS run on different time scales. The subsequent point is that GPS receivers normally are the devices that apply the correction. Now, if you want to talk about being able to set an alarm clock for a future event, that's an interesting discussion. What interval should I set the timer for? :-). KR _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Walt Williams " Subject: PSN-L: Solar Super Flares Date: Wed, 6 Jan 1999 17:20:43 -0800 All, Little off-topic post, but very interesting. FYI. Cross posted from the Search for ExtraTerrestrial Intelligence - League (SETI-L) open list. Walt Williams, 99.01.06 PSN Stn 63 dfheli@.............. ============================================ Date: Wed, 6 Jan 1999 22:39:40 GMT From: Ron Baalke To: astro@.................... Subject: Yale Astronomers Study Superflares on Stars Just Like Our Sun Sender: owner-astro@......................... Reply-To: Ron Baalke Subject: Re: Year 2000 Calendar Date: Thu, 07 Jan 1999 09:49:35 +0800 Hi All, The year 2000 is a LEAP year. Our passage through the seasons is called a "tropical" year of 365.24.. days long. This awkward fraction 0f 0.24... days is nearly a 1/4 of a day. So Pope Gregory on the advice of the astronomer Clavius adopted this solution. Every forth year we add a day (leap year). To correct for the errors in the fraction we make the century years that are divisible by 400 a leap year. (There is also a 4000 year correction). So 1900 was not a leap year but 2000 will be a leap year. Calendars that are the same: Look identical (other than festivals) 1) ..,1989, 1995, 2006, 2017 (not a leap year) 2) ..,1990, 2001, 2007, 2018 "" 3) ..,1991, 2002, 2013, 2019 "" 4) ..,1997, 2003, 2014, 2025 "" 5) ..,1998, 2009, 2015, 2026 "" 6) ..,1999, 2010, 2021, 2027 "" 7) ..,2005, 2011, 2022, 2033 "" 8) ..,1928,1984, 2012, 2040 (LEAP YEAR) 9) ..,1968,1996, 2024 L 10) ..,1952,1980, 2008,2036 L 11) ..,1908,1964, 2020,2048 L 12) ..,1948,1976, 2004,2032 L 13) ..,1904,1960, 2016,2044 L 14) ..,1944,1972, 2000,2028 L ******** Ragards Arie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Year 2000 Calendar: simple algorithm for leap yrs. Date: Wed, 06 Jan 1999 19:25:46 -0700 (MST) A simple algorithm for determining leap years would simply be to see if the year is divisible by four and the result be a whole number... eg. 2000/4 = 500 leap 2001/4 = 500.25 not 2002/4 = 500.5 not 2003/4 = 500.75 not 2004/4 = 501 leap 2005/4 = 501.25 not etc., as long as they keep doing it every four years... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Kevin J. Rowett" Subject: Re: Year 2000 Calendar: simple algorithm for leap yrs. Date: Wed, 06 Jan 1999 18:59:01 -0800 At 06:25 PM 1/6/99 , you wrote: >A simple algorithm for determining leap years would simply be to see if the >year is divisible by four and the result be a whole number... > >eg. 2000/4 = 500 leap > 2001/4 = 500.25 not > 2002/4 = 500.5 not > 2003/4 = 500.75 not > 2004/4 = 501 leap > 2005/4 = 501.25 not >etc., as long as they keep doing it every four years... Yet, 1900/4 = 475 "evenly divisible", 1900/400 = 4.75; 4 with a remainder of 75 (1900 wasn't a leap year). 2100 is similiar. KR _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Mark Robinson" Subject: Re: Year 2000 Calendar Date: Thu, 7 Jan 1999 16:39:31 +1300 Just a wee vote for Arie's leap year algorithm. What he states is what I was taught at univeristy while learning to program. Shame that certain more successful programmers didn't. Happy New Year Mark G Robinson | ZL2TOD | other@............... Box 8770, Auckland 1035, New Zealand Phone +64-9-846-3296 | Fax +64-9-849-7408 ------------------------------------------------ 07 Jan 1924 George Gershwin composes Rhapsody in Blue. 07 Jan 1952 Ike offers to accept GOP Presidential Nomination. ----- Original Message ----- From: Arie Verveer To: PSN-L Mailing List Sent: Thursday, 7 January 1999 14:49 Subject: Re: Year 2000 Calendar >Hi All, > >The year 2000 is a LEAP year. Our passage through the seasons is >called a "tropical" year of 365.24.. days long. This awkward fraction >0f 0.24... days is nearly a 1/4 of a day. So Pope Gregory on the advice of >the astronomer Clavius adopted this solution. Every forth year we add a >day (leap year). To correct for the errors in the fraction we make the century >years that are divisible by 400 a leap year. (There is also a 4000 year >correction). So 1900 was not a leap year but 2000 will be a leap year. > >Calendars that are the same: Look identical (other than festivals) > > 1) ..,1989, 1995, 2006, 2017 (not a leap year) > 2) ..,1990, 2001, 2007, 2018 "" > 3) ..,1991, 2002, 2013, 2019 "" > 4) ..,1997, 2003, 2014, 2025 "" > 5) ..,1998, 2009, 2015, 2026 "" > 6) ..,1999, 2010, 2021, 2027 "" > 7) ..,2005, 2011, 2022, 2033 "" > > 8) ..,1928,1984, 2012, 2040 (LEAP YEAR) > 9) ..,1968,1996, 2024 L >10) ..,1952,1980, 2008,2036 L >11) ..,1908,1964, 2020,2048 L >12) ..,1948,1976, 2004,2032 L >13) ..,1904,1960, 2016,2044 L >14) ..,1944,1972, 2000,2028 L ******** > >Ragards Arie > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Dewayne Hill Subject: Y2K Date: Thu, 07 Jan 1999 08:11:14 -0700 I'm not one that gets upset very easily but I think all of the E-Mails about Y2K problems would be better communicated on one of the Y2K user groups rather that filling up the PSN server and my mail box. Regards, A nagging old man Dewayne (n0ssy) & Linda (n0uqf) Hill Westminster, Colorado USA 39.83569n 105.06270w. Elev 5460ft. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Roger Griggs Subject: Re: Year 2000 Calendar Date: Thu, 07 Jan 1999 16:46:08 -0800 John, Our Electric Transmission Control system log showed a leap second added via GPS TIME at 16:00 PST, Dec 31, 1998. This would have been 00:00 Jan 01, 1999 GMT. And yes, in a realtime control system, these leap seconds are a hassle. Roger At 12:56 PM 1/6/99 -0700, you wrote: >On Wed, 6 Jan 1999, bc wrote: >> At 09:25 AM 1/6/99 -0500, you wrote: >I think the only rule for leap years is an extra day in February (the 29th) >every four years. This is because the year is approximately 365 and 1/4 days >long. I think we also have leap seconds every year, but I am not sure if that >is just rumor or truth... For those using WWV though, these leap seconds >could be a hassle; that is, if they exist. > >Also, the only thing special anyone is doing for 2000 that I have heard >about is going to Jerusalem and vowing to die in a violent fight to prepare >the way for the second coming... I have a feeling that this type of thing >will be a problem for governments worldwide this year... > >*************************************************************************** *** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > http://www.public.asu.edu/~hernlund/ > >*************************************************************************** *** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: peaches@............ (Donna Whitaker) Subject: USGS Geological Hazards Report Date: Thu, 7 Jan 1999 15:06:37 -1000 (HST) News Release U.S. Department of the Interior U.S. Geological Survey Office of the Eastern Regional Geologist 953 National Center Reston, VA 20192 Release: Upon Receipt (Jan. 7, 1999) Contact: Diane Noserale dnoseral@........ 703-648-4333 Fatalities Increase in 1998, but . . . Earthquake Death Toll Still Below Long-Term Average Note to editors: Because of the nature of earthquake data collection, information on these events should be considered preliminary. We will issue an update if necessary. At least 8,928 people were reported killed from earthquakes world wide in 1998, according to the U.S. Geological Survey National Earthquake Information Center (NEIC) in Golden, Colo. Although this is a three-fold increase over the 1997 toll of 2,907, and a twenty-fold increase over the 1996 total of 419 deaths, it is still under the long-term average of about 10,000 earthquake-related deaths in the world each year. "This is the 5th consecutive year in which the death toll has been below average world wide," said Waverly Person, Director of the USGS NEIC. "The border area of Afghanistan and Tajikistan bore the brunt of fatalities in two events (at least 6,323 fatalities), neither of which was the strongest earthquake for the year or even classified as a major earthquake," Person explained. The strongest earthquake in 1998, one of only two great earthquakes recorded in the world in 1998 (magnitude 8.0 or above), occurred on March 25 in the Balleny Islands region, between Australia and Antarctica. Its magnitude was 8.3. The other great earthquake occurred on Nov. 29 in the Ceram Sea, near Sulawesi, Indonesia. That earthquake's magnitude was 8.1 and at least 34 people were killed. Only ten earthquakes were classified as "major." Major earthquakes have a magnitude of 7.0-7.9. According to long-term records, an average of 20 major earthquakes occur in the world per year. "No fatalities occurred in the U.S. in 1998 from earthquakes; however two people were reported injured in the August 12, magnitude 5.3 earthquake in southern Santa Cruz County, California," said Person. Three earthquakes of magnitude 6.2 were the strongest recorded in the U.S. in 1998. All occurred in Alaska: July 9 in southern Alaska, Aug. 20 and Sept. 14 in the Aleutian Islands. "A magnitude 5.2 earthquake on the Ohio-Pennsylvania border on Sept. 25 generated the greatest number of inquiries to the NEIC. Although this earthquake did not cause very much damage, it was felt strongly throughout northern Ohio and most of Pennsylvania. It was also felt in Illinois, Indiana, Michigan, New Jersey, New York, and southern Ontario, Canada," said Person. "We continue to hear from many people throughout the world that earthquakes are on the increase. Although it may seem that we are having more earthquakes, this is not the case. In fact, earthquakes of magnitude 7.0 or higher have remained fairly constant throughout this century," Person noted. A partial explanation for the impression of increased earthquakes may be that in the last twenty years, we have definitely had an increase in the number of earthquakes USGS has been able to locate each year. This is because of the tremendous increase in the number of seismograph stations in the world and the many improvements in global communications. Besides enhancing public safety, this increase in the number of stations and the more timely receipt of data has allowed seismological centers to locate many small earthquakes which were undetected in earlier years, and we are able to locate earthquakes more rapidly. Also, because of the improvements in communications and the increased interest in natural disasters, the public now learns about more earthquakes. Also, the effect that earthquakes have when they strike is generally more pronounced. Although we have gained much knowledge in building safer structures, when earthquakes occur today, losses (both human and property) are greater in many areas of the world. This is not because the earthquakes are stronger; it is simply because the Earth's population is increasing and more property (much of it not built to withstand earthquakes) exists that can be destroyed in an earthquake. USGS estimates that several million earthquakes occur in the world each year. Many of these earthquakes go undetected because they occur in remote areas or have very small magnitudes. The USGS locates about 18,000 to 20,000 earthquakes each year (about 50 per day). Additional information on the year's earthquakes is available on the USGS NEIC Homepage at: http://wwwneic.cr.usgs.gov/ As the nation's largest water, earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 2000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, to contribute to the conservation and the sound economic and physical development of the nation's natural resources, and to enhance the quality of life by monitoring water, biological, energy, and mineral resources. ### USGS ### This press release and in-depth information about USGS programs may be found on the USGS home page: http://www.usgs.gov. To receive the latest USGS news releases automatically by email, send a request to . Specify the listserver(s) of interest from the following names: water-pr; geologic-hazards-pr; biological-pr; mapping-pr; products-pr; lecture-pr. In the body of the message write: subscribe (name of listserver) (your name). Example: subscribe water-pr joe smith. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Steve Jones Subject: Re: Year 2000 Calendar Date: Thu, 07 Jan 1999 19:30:51 -0800 Larry Cochrane wrote: > > At 02:40 PM 1/6/99 -0700, you wrote: > >"Kevin J. Rowett" wrote: > > > >> So GPS time is now 13 seconds ahead of UTC. > > > >Larry C., is SDR using the offset in it's time with your GPS reciever? > >It would probably be pretty obvious if it's not. It would be kinda fun > >to watch it handle the leap second as it happens, if it does look at > >that. > > > >,Greg > > When I added the GPS support too SDR I didn't notice a 13 second offset > problem, so the ONCORE GPS receiver must be handling this.... > > -Larry Cochrane > Redwood City, PSN > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L Just thought I'd add my .02 re: the "GPS offset". If you fire up a "cold" (non-initialized) Oncore (or any other, I suppose) GPS receiver, you can watch the offset correction from GPS time occur a few minutes after the receiver first acquires a complete time solution. It is simply a (currently) 13-second decrement in the seconds output message. From the Oncore tech manual: "...The UTC [GPS offset] parameters are broadcast by the satellites as a part of the almanac, which is repeated every 12.5 minutes...The value reported is the integer number of seconds between UTC and GPS time..." Steve Jones _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: CARRJJ@....... Subject: Assistance?? Date: Thu, 7 Jan 1999 21:45:06 EST Can anyone direct me to sources of information on seismic instruments, hardware and their application suitable for amateur or hobbyist level people? Joseph J. Carr POB 1099 Falls Church, VA 22041 CARRJJ@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Re: Assistance?? Date: Thu, 07 Jan 1999 23:07:03 -0400 Joseph Visit the PSN site at: http://psn.quake.net/ Wayne CARRJJ@....... wrote: > Can anyone direct me to sources of information on seismic instruments, > hardware and their application suitable for amateur or hobbyist level people? > > Joseph J. Carr > POB 1099 > Falls Church, VA 22041 > CARRJJ@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: JIm Hannon Subject: Re: Assistance?? Date: Thu, 07 Jan 1999 21:41:45 -0600 CARRJJ@....... wrote: > Can anyone direct me to sources of information on seismic instruments, > hardware and their application suitable for amateur or hobbyist level people? > > Joseph J. Carr > POB 1099 > Falls Church, VA 22041 > CARRJJ@....... > > Just start asking questions on this list. Also it is well worth the time to read the archives of the list at http://psn.quake.net/maillist.html#archives -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: Assistance?? Date: Thu, 07 Jan 1999 20:01:46 -0800 Hi Joe Scientific American - Amatuer scientist.( Older editions) Barry CARRJJ@....... wrote: > Can anyone direct me to sources of information on seismic instruments, > hardware and their application suitable for amateur or hobbyist level people? > > Joseph J. Carr > POB 1099 > Falls Church, VA 22041 > CARRJJ@....... > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: box to dominica Date: Thu, 07 Jan 1999 23:13:19 -0700 Meredith- I apologise for taking so long to get back to you on the subject, but now that I've been back from Dominica for a week, I figured I'd tell you just what happened to your box (I'll start with a short background for the blissfully innocent). [Meredith arrived at my USGS Golden, Colorado, office on Saturday afternoon, 19 Dec, the day before Jody and I departed for Dominica, with a large cardboard box, ~30x20x60 cm, i.e., 12x8x24 in, that was also quite heavy, ~10-15 kg, i.e., 20-30 lbs. When I saw how big his box was relative to the heavy-duty plastic shipping case I was planning to pack all the seismic equipment I was bringing to Dominica -- including a 3-channel amplifier board, an SDR board, a PC-LABS A/D board & manual from Larry Cochrane; a L-28 vertical geophone from Roger Vaught; an antenna mount from Rick Curtis; and a 3-component L-22 geophone on loan from USGS -- I suggested to Meredith that maybe I could leave the box itself and only pack the contents, but he did not look particularly enthusiastic about that idea.] It was only in my typically last-minute rush of packing the next morning a couple of hours before our departure that I looked in the box and realized that it contained many of the pieces in semi-kit form of a Lehman seismometer -- including what looked to my hasty inspection like a LARGE MAGNET -- and that all the components were carefully and securely packed in their respective bags and plastic jars. So I packed the whole box as it was in the shipping case and everything else fit in quite snugly as well, and I wrapped up the shipping case with meters of fiber tape so that it looked like a bandage-swathed plastic coffin holding a PVC Mummy from the petrochemical swamps of New Jersey industrial wasteland. However, as soon as we started to checkin at the Denver airport, the man at the counter wanted to know if the shipping case contained "any magnets". Since I have shipped literally tons of seismic equipment using the same shipping cases while chasing earthquakes with USGS and have never been questioned about their contents, I was, in terms of speaking the truth, caught with my pants down, and I answered that it contained one magnet weighing several pounds (i.e., half that many kilograms). That triggered several long telephone consultations with various airline experts and other officials during which I was questioned -- causing me to babble about working for the USGS even though all our other statements indicated that we were on a personal vacation -- and which included discussions of "compass checks". That made me think that perhaps Meredith's supermagnet might misnavigate us to Cuba rather than Dominica. And then of course, there were all the questions about whether anyone unknown had given us any items to carry (of course not, I know all these people on the PSN-L whom I have never met face-to-face and who have sent me these strange boxes better than I know my mother). Anyway, everything arrived safely, and shortly before I left Dominica when I explained to Wayne that he could use your pieces to build a Lehman to monitor teleseisms, he got enthusiastic about that project. Though the groundmotion theshhold detector you sent Wayne was described to me in Dominica, I never actually saw it because it and Jody & I were never quite in the same place at the same time as we made our respective journeys around the island, though I understand it is at residence at Andre'&Joyce's, which is a shaking kind of place. Anyway, I have a couple of items from Dominica* to give to you and Lee Ann (maybe Chipper might also like them?), and I am planning to ride my bicycle over to your home (I need the exercise after not being able to ride on Dominica because the roads were just as crazy for the naive American as I was told they would be by Wayne and Clem) this weekend and drop them off. What would be a good time for you? -Edward * I also have a couple of things for others who contributed equipment but I am not planning to ride my bicycle to Texas and California. meredith lamb wrote: > Hi Edward, > > Have box for Wayne in Dominica ready for pickup. We maybe in > and out over the next few days....maybe if I leave it out front just > in case, we miss meeting? Hope you remember address here.... > 715 S. Pecos St. Denver, Co. ph 303-936-6221 > > or......we can deliver to your place? > > Thanks, Meredith, Lee Ann and Chipper the dog. > > -- > Meredith Lamb > <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> > > Main Web site: http://www.users.uswest.net/~psnseismograph52/Index.html > > <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Baffled Date: Fri, 08 Jan 1999 00:22:31 -0700 Wayne- Four seconds of first motion of the seismogram you sent me 990101j.dm[1-3] is shown in the plot below (using my old VECTOR prog ram): ftp://groundmotion.cr.usgs.gov/PSN/Dominica/01jan1999/FIRSTMOT.GIF All three components are plotted at the same amplitude scale. Note that the Z- (Ch1) and N- (Ch2) components are similar and th at their first arrivals precede that of the E-component (Ch3) by 0.10-0.15 s but then the E is much larger and more impulsive. All the c omponents are very monochromatic, and you can see from the WinQuake FFT that the spectra peak at 4-6 Hz. In short, this is another weird seismogram, and I am not sure what is P & S and what is what (are all the channels connected 1, 2, 3? ... a rude question but I had to ask) . It maybe something idiosynchratically volcanic, but I am not very familiar with those seismograms. Have you recorded anything as simple as that first event on 27 Dec, i.e., large P on Z followed by large S on N&E? If you have, please send it to me. You should be able to use SDR as a voltmeter. Take a sinusoidal signal, e.g., Delores tapping the Z-component of the L-22 and i nput that directly into Ch1 of the SDR. Take the same signal in parallel and input it into the amplifier and then take the amplifier outp ut and input that into Ch2 of the SDR. Calculate the amplification by dividing the digital counts of Ch2 by those of Ch1. By controlli ng how hard she taps, Delores should be able to produce a signal that is on-scale in both straight and amplified versions. Save both record s and send them to me, and I will calculate the overall response of the amplifier using spectral ratios. -Edward Wayne Abraham J73WA wrote: > Ed, > > I will take up the direction finding subject with you again later because I am definitely going to have to use it alot and I want to > understand it properly. > > Larry told me how to change the frequency from 10 to 20hz which I did today. I also increased the sampling rate to 100. The m inute I > changed the frequency, my trace seemed to become at least 5 times wider than it was. I guess I will now have to reduce my gai n some > more. I have asked Larry how I can use my multimeter to know my gain. If he replies tomorrow, I will to back to Roseau to get it done. > > Seismic activity seems to have subsided somewhat. That's good because I want to be well calibrated when it decides to return. > > Take care, > > Wayne -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Al Allworth" Subject: Test Date: Sun, 10 Jan 1999 00:40:11 -0800 Real quiet for 2 days. ____________________________________ Al Allworth allworth@.............. Gold Beach On The Beautiful Southern Oregon Coast ____________________________________ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Bob Fryer Subject: Re: Test Date: Sun, 10 Jan 1999 01:07:01 -0800 Hi Al, Yeh, real quiet. I got dumped from another list the other day. Bob -- in the dripping PNW (Beaverton, OR) >Real quiet for 2 days. >____________________________________ > >Al Allworth allworth@.............. > >Gold Beach > >On The Beautiful Southern Oregon Coast > >____________________________________ ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/~bfryer --- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "anthony p. giunta" Subject: event in New England Date: Sun, 10 Jan 1999 18:23:49 -0500 @ 5:52 am quake measuring 2.7, epicenter was located at Merrimac, Massachusetts A. P. Giunta Norwood, Mass _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: New WinQuake beta release Date: Sun, 10 Jan 1999 17:22:32 -0800 Hi Everyone, Happy New Year. In the last few months I have been working on a new Winquake (WQ) release. With some help from Arie Verveer (thanks Arie!) I think I have a stable beta release ready.I sent Arie a pre-beta release so he could checkout one of the new features in this release. I used the code he wrote to convert GSE2.0 files to the PSN format to allow WQ to view event files in that format. He ended up finding a few major bugs that where not happening on my system. Heres what's new in this release (Version 2.5.7 Beta): Mapping and Event Location: This is the main new feature in this release. After opening one or more event files and picking the P and S phase, a map can be drawn showing the stations with a distance circle. This can be used, if you have good P and S picks, to locate the event. To open a map window, click on the new map tool bar icon next to the RST (Reset) icon or use the "View/Locate Event" menu item. After opening a map window, you use the Zoom menu to zoom in and out. To move the globe around, double click on a point on the globe. This will move the map so that this point is now centered in the window. I still need to add some tool bar icon controls and come up with a better way of moving the map around. GSE2.0 support: WinQuake uses the keyword "BEGIN GSE2.0" to see if a file is in the GSE2.0 format. This keyword must be within the first 512 bytes of the file. WQ supports both single and multiple seismograms in one GSE2.0 file. If there is more than one seismogram in a file, it will be treated the same way as a PEPP or SEED volume data set. IASP91 travel time model: The option, controlled by the Travel Time Table and Display Phase control dialog boxes, uses the IASP91 travel time tables instead of the JB tables. There isn't much difference between the two sets of tables except that the IASP91 P and S tables go past the 107 degree point. Apparently they use some other first arrival P and S phases once the main P and S go into the earth's core shadow. Too enable this option, the file IASPI91.DAT must be in the WQ root directory. New Event Window Look: The Event Window now is divided into two sections using a splitter window. The text or header information is displayed in one window and the seismogram is displayed in another. Using the Options menu items you can control the colors and font of each window. You can download the new beta release at ftp://ftp.drnet.com/users/psn/software/wqbeta257.zip. If you are having problems with that link, the FTP server is hanging sometimes, you can download the file at ftp://ftp.seismicnet.com/software/wqbeta257.zip. The file is about 1.3 meg bytes in size. The zip file only contains a new winqk32.exe and some new and old data files. To use this release you must have an older version of WQ installed. After unzipping the beta release file in a temp directory copy all of the files to your main WQ root directory. You might want to rename the exciting winqk32.exe file before you do the copy. Note: The beta release is only for Windows 95/98 or NT. I won't be supporting the 16 bit version any more. Also, since this is a beta release the program will time out at the end on April. That's it. Let me know if you find any problems, have any suggestions or need any help with the new features in this beta release. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Re: New WinQuake beta release Date: Sun, 10 Jan 1999 23:42:00 -0400 Larry Will I lose my registration when the program times out in April? Wayne _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: New WinQuake beta release Date: Sun, 10 Jan 1999 21:07:46 -0800 At 11:42 PM 1/10/99 -0400, Wayne wrote: >Larry > >Will I lose my registration when the program times out in April? > >Wayne No... -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: VBB transducer sensitvity Date: Mon, 11 Jan 1999 00:59:20 -0600 (CST) For those interested in the displacement detector used for the triple-feedback broadband seismometer: An update on the VRDT used for the STM-8 VBB seismometer: THE Conclusion: experiments indicate that configuring it per pervious specifications may make it TOO sensitive. I have re-evaluated the oscillator frequency question and gathered this information, some of which has been previously noted: a: The inductance of the VRDT when made with the TL021 transformer with the vane centered in a 2mm gap is 125 millihenries (per side). This calculates to an impedance of 3.9k ohms at 5khz, and 470 ohms at 600 hz. This would be the effective bridge impedance. b: With the borrowed digital LCR meter, I measured the inductance change as the vane is moved with the micrometer. Of course one side increases as the other decreases, so the changes need to be summed. They average 70 micro-henry per micron. This is a change of the reactance of each side of the bridge of 2.26 ohms per micron at 5 khz, and 0.27 ohms per side at 600 hz. Clearly the 5 khz (or even higher?) frequency gives much more sensitivity. c: The 600 hz option is used for the tiltmeters because it greatly reduces reactive changes caused by temperature, etc, of the long (over 10 meters) cables that are used. For the seismometer, the bridge can be within a few cm of the VRDT, so this is much less a problem. (Also, the tiltmeters are electrolytic resistive bridges, whose output was not frequency dependent.) As long as the bridge excitation is a clean sine wave, without high frequency harmonics, reactive changes should be minimized. d: SO... It seemed that the sine frequency should be 5 khz for maximum sensitivity. This makes the bridge impedance 4.02k ohms (at 1%), which is what it was designed for, and how I have drawn the schematic. BUT.... THis makes the transducer so sensitive that it is almost impossible to calibrate. (I actually changed one oscillator to 10khz for an application to a geophone, then studied the noise with the TL021 coils.) e: SO... It seems that for the present the 600 hz frequency is preferred. With the output of the oscillator at the transformer set to 350mv RMS, or 1 volt p-p referred to common, the transducer output is about 120 mv/micron. THe sensitivity does scale with the drive level. This sensitivity can be very roughly checked by turning the 30-turn, 100 ohm zero potentiometer in successive 1-turn steps. Since the transducer net reactance change is 0.5 ohms/micron at 600 hz, 3 ohms will represent 6 microns, or 720mv. (The "calibration" resistors and switch will produce the same result if they are installed.) So with the differential micrometer calibration, which is really only useful at 5 or 10 micron steps, the +,- 7 volt working range is spanned in 10 or 20 steps, which limits the statistics of the direct VRDT calibration. With the displacement gain amplifier at 20X, which is needed for the very high value of "r" in the feedback system, a level of 2400 mv/micron requires calibration by much higher resolution devices. However, its output is an indication of the system noise, which is about 1 mv p-p from 10 hz to DC. This is an equilavent ground noise of about 0.4 nanometers. I have recently operated the STM broadband vertical with a r value as high as 2 000 000 V/m. This extends the frequency response to above 100 hz. And of the differential capacitor Cp is reduced for a shorter natural period. like 50 seconds, the flat response level is very high, like 11 700 v/m/sec. It makes for very large 6-second microseisms. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Francesco" Subject: R: New WinQuake beta release Date: Mon, 11 Jan 1999 12:19:20 +0100 Hello Larry, very good the new release of WQ! =20 One suggestions for the definitive version: the automatically save of = the files map in gif format . This option would be useful, because it = would simplify the job of conversion with clipboard and another graphic = programm. A question. New Winquake read automatically the GSE2.0 file? =20 Regards Francesco Nucera - I.E.S.N. PSN ITALY
Hello Larry,
very good the new release of = WQ! 
One=20 suggestions for the definitive version: the automatically save of the = files map=20 in  gif format . This option would be useful, because it would = simplify the=20 job of conversion with clipboard and another graphic = programm.
 
A question. New Winquake read=20 automatically  the GSE2.0 file? 
 
Regards
Francesco Nucera  - I.E.S.N. = PSN=20 ITALY
From: "Francesco" Subject: AutoDRM and GSE2.0 Date: Mon, 11 Jan 1999 12:23:23 +0100 Arie, wich is the system now, with the new beta release of Winquake, to read = the GSE2.0 file, via AutoDrm and e-mail request? Bye Francesco Nucera - I.E.S.N. - PSN ITALY
Arie,
wich is the system now, with the new = beta=20 release of Winquake, to read the GSE2.0  file, via AutoDrm and = e-mail=20 request?
 
Bye
Francesco Nucera   -  = I.E.S.N. -=20 PSN ITALY
From: Arie Verveer Subject: Re: AutoDRM and GSE2.0 Date: Mon, 11 Jan 1999 21:00:28 +0800 Hi Francesco, > wich is the system now, with the new beta release of Winquake, to read the GSE2.0 file, via > AutoDrm and e-mail request? You will still need to send your Email requests to your AutoDRM provider and save the returned data as a file. From then on I would use Larry's new release of Winquake. Its the complete package. The only thing you should be aware of , GSE2.0 files do contain checksum errors. They appear to be some sort of marker in the GSE2.0 file data. If you get a checksum error its better to decode the data via the "dos" program. It has some "fudge" code to ignore the checksum and extract the data that doesn't comply with the GSE2.0 standard. It only happens occasionally. I found using AutoDRM files in Winquake to be a grand way of locating epicentres. I used that feature today to locate a epicentre from a mine blast. All the best Arie. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: robert barns <75612.2635@..............> Subject: MA 'quake Date: Mon, 11 Jan 1999 10:02:39 -0500 Hi gang, An item which might tickle the risibilities of you Californians-- = There was a 'quake yesterday near Merrimac, MA which registered 2.7 on t= he Richter scale! This made the CBS TV 11PM news in NYC. Any questions about what we do for excitement in this part to the worl= d? Bob Barns = = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Bonnie Subject: 75612.2635@.............. Date: Mon, 11 Jan 1999 22:29:02 -0600 MA 'quake Hi, I can remember, when I was living in Oregon, that I thought that a 2 quake was a biggy! Then I moved to CA and got reedgucated real fast. Bonnie the crafty crafter Net-Tamer V 1.10 - Registered _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "anthony p. giunta" Subject: Re: 75612.2635@.............. Date: Tue, 12 Jan 1999 20:02:08 -0500 Well thats how it is in New England, Our observatory has quakes all of the time but not like your area...............Thanks Tony -----Original Message----- From: Bonnie To: psn-l@.............. Date: Tuesday, January 12, 1999 01:56 AM Subject: 75612.2635@.............. >MA 'quake > >Hi, I can remember, when I was living in Oregon, that I thought that a 2 >quake was a biggy! Then I moved to CA and got reedgucated real fast. > > >Bonnie >the crafty crafter > >Net-Tamer V 1.10 - Registered > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Arie Verveer Subject: Little quakes from distant BIG quakes Date: Wed, 13 Jan 1999 11:24:18 +0800 Hi, This may be a silly question but has anyone noticed that on some occasions a small local quake occurs very shortly after a big quake, even though the big quake has an epicenter many thousands of kilometers away ..? I have just posted a seismogram from the New Britain event (990112b.au1) that shows this. If you look at the low frequency recording of the event, nothing much appears. Typical with a local event. (990112b.au2) Arie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Arie Verveer Subject: Mb5.4 Talaud Island Indonesia Date: Wed, 13 Jan 1999 11:48:23 +0800 From: Arie Verveer Subject: Opps Date: Wed, 13 Jan 1999 12:50:57 +0800 Hi, Sorry about sending the an event to the PSN mailing list. Arie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Little quakes from distant BIG quakes Date: Wed, 13 Jan 1999 17:48:56 -0700 (MST) On Wed, 13 Jan 1999, Arie Verveer wrote: > Hi, This may be a silly question but has anyone noticed that on some > occasions a small local quake occurs very shortly after a big quake, > even > though the big quake has an epicenter many thousands of kilometers away > .? Arie, A lot of people in the western US talk about earthquake triggering, and how waves from one event can alter the stress field just enough to start an event very far from away. Hence the triggered quake would happen in an area where the stress is very close to the strength of the fault; poised on edge I suppose. This case works very well for areas with a lot of small quakes (high b-value) like the Geysers, Yellowstone, or perhaps even Long Valley. This is a very interesting topic, but I don't think it is well accepted through out the seismology community. After all, the faulting process is not that well understood yet... If I remember correctly, quite a few USGS folks have been working on this very problem... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Taber Subject: Re: Little quakes from distant BIG quakes Date: Thu, 14 Jan 1999 15:47:46 +1300 (NZDT) Arie, You wrote: >This may be a silly question but has anyone noticed that on some >occasions a small local quake occurs very shortly after a big >quake, even though the big quake has an epicenter many thousands of >kilometers away? It doesn't sound like a silly question to me. There has been a lot of interest in the past few years in the possibility of large earthquakes triggering small earthquakes at a distance. The best example of this was the Landers earthquake in 1992. I don't know if anyone has found evidence of triggering thousands of km from a M6 eathquake, but it might be interesting to keep track of the number of times you see a small local earthquake just after a big distant earthquake, and compare this to the frequency of small local earthquakes. Cheers, John Taber _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: CNSS Catalog Date: Thu, 14 Jan 1999 22:10:25 -0400 PSN Does anyone on this list know how to access the CNSS catalog using Winquake? This catalog seems to have quite a few quakes for the Caribbean region reported by the Puerto Rico station. Thanks, Wayne _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Bonnie Subject: taber@............. Date: Sat, 16 Jan 1999 21:59:30 -0600 Little quakes from distant BIG quakes Hi, I believe that there were two smaller quakes just before the 8.3 quake in 1857 at Fort Tajone. Sorry about the spelling. Bonnie the crafty crafter Net-Tamer V 1.11.2 - Registered _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Doug Crice Subject: Old seismograph Date: Mon, 18 Jan 1999 08:58:07 -0800 What is aledged to be an early, wind-up seismograph is for sale on e-bay.com at http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=56865800 So far, the price is reasonable, but I know nothing other than what is on the site and that the vendor seems well regarded by prior customers. You have 3 days until close of the auction. -- Doug Crice web site http://www.georadar.com GeoRadar Inc. e-mail dcrice@............ 19623 Via Escuela Drive phone 408-867-3792 Saratoga, CA 95070 USA fax 408-867-4900 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Robert Avakian Subject: Re: Old seismograph Date: Mon, 18 Jan 1999 11:34:06 -0800 Looks like a barograph from the photos. Notice the vents on the top and sides, I doubt a seismograph would have that. Bob Avakian Doug Crice wrote: > > What is aledged to be an early, wind-up seismograph is for sale on > e-bay.com at > > http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=56865800 > > So far, the price is reasonable, but I know nothing other than what is > on the site and that the vendor seems well regarded by prior customers. > You have 3 days until close of the auction. > -- > Doug Crice web site http://www.georadar.com > GeoRadar Inc. e-mail dcrice@............ > 19623 Via Escuela Drive phone 408-867-3792 > Saratoga, CA 95070 USA fax 408-867-4900 > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: ACole65464@....... Subject: Re: Old seismograph Date: Mon, 18 Jan 1999 22:25:08 EST The item that eBay is offering, to me, looks like a 30+ year old thermograph (recording thermometer). Any one else would like to take a guess? Allan Coleman, Edmonds, Wa. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: New Event? Date: Mon, 18 Jan 1999 21:03:45 -0800 Hi All Did anyone pick up an event around 15:53 UTC? I used Larry's new event locator (great addition) and it maybe in Central America or Alaska or maybe my machine acting up :-) Regards Barry. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: New Event Date: Mon, 18 Jan 1999 21:09:52 -0800 Opps I think the time would be 04:54:00 UTC Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Canie Brooks Subject: Re: New Event Date: Mon, 18 Jan 1999 21:15:45 -0800 At 09:09 PM 1/18/99 -0800, barry lotz wrote: >Opps > I think the time would be 04:54:00 UTC > Barry Take a look at this site: http://aslwww.cr.usgs.gov/Seismic_Data/heli2.htm Something happened! > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Canie Brooks Subject: Re: New Event Date: Mon, 18 Jan 1999 21:15:45 -0800 At 09:09 PM 1/18/99 -0800, barry lotz wrote: >Opps > I think the time would be 04:54:00 UTC > Barry Take a look at this site: http://aslwww.cr.usgs.gov/Seismic_Data/heli2.htm Something happened! > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dewayne (n0ssy) & Linda (n0uqf) Hill" Subject: New Event Date: Tue, 19 Jan 1999 05:18:00 +0000 Arival time in Westminster Co. (39.835n 105.062w) was 04:20:15 GMT. Dewayne (n0ssy) & Linda (n0uqf) Hill Westminster, Colorado USA 39.83569n 105.0627w Elev. 5660ft. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dewayne (n0ssy) & Linda (n0uqf) Hill" Subject: RE: new event Date: Tue, 19 Jan 1999 05:48:47 +0000 Earlier reported 04:20:15 may be "S" wave, With "P" at 03:50:12 UTC. Dewayne (n0ssy) & Linda (n0uqf) Hill Westminster, Colorado USA 39.83569n 105.0627w Elev. 5660ft. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: New Event Date: Mon, 18 Jan 1999 21:53:37 -0800 Canie I like the link. Thanks. Regards Barry Canie Brooks wrote: > At 09:09 PM 1/18/99 -0800, barry lotz wrote: > >Opps > > I think the time would be 04:54:00 UTC > > Barry > > Take a look at this site: > http://aslwww.cr.usgs.gov/Seismic_Data/heli2.htm > > Something happened! > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Seisguy@....... Subject: Fwd: USGS Earthquake report Date: Tue, 19 Jan 1999 01:17:53 EST Magnitude 6.4 earthquake near NEW IRELAND REGION, P.N.G. 4.36S, 153.16E depth 114.3km Tue Jan 19 03:35:33 1999 GMT An earthquake has occurred. Following is information provided by the National Earthquake Information Service of the USGS. This information is preliminary and subject to correction. Time: GMT Tue Jan 19 03:35:33 1999 (EST Mon Jan 18 22:35:33 1999) (PST Mon Jan 18 19:35:33 1999) Magnitude: 6.4, determined using its surface wave characteristics Epicenter: 4.36S, 153.16E (NEW IRELAND REGION, P.N.G.) Precision: B, where A is fine and D is coarse. Depth of focus: 114.3km below sea level at the epicenter. For a map showing this event, please consult the web page Further info can be obtained from the USGS National Earthquake Information Center at or the USGS home page at You will continue to receive messages like this when earthquakes occur that have magnitude 5.0 or more in the continental US, Alaska, and Hawaii, and 6.0 or more anywhere in the world The subscription form for this service is at If you do not wish to receive these messages, please visit that subscription form, enter your email address, and select "unsubscribe". If that does not stop the messages, please send email to info@................ -- U.S. Geological Survey -- Science for a Changing World From: Karl Cunningham Subject: UPS's Date: Tue, 19 Jan 1999 10:05:47 -0800 Hi all -- I noticed that CompUSA (in Southern California, at least) has a 300 watt Uninterruptable Power Supply on sale for $80 this week. This could make a relatively inexpensive backup power supply for home-made seismometers. The ad doesn't say how long it will provide that amount of power. As a reference, my seismometer electronics and computer running SDR consume about 40 watts without the monitor. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Angel Rodriguez Subject: Re: UPS's Date: Tue, 19 Jan 1999 14:04:17 -0500 Hi All, I use a 325 VA UPS much like the one Karl mentions and it worked well for about 30 minutes (no monitor). Then I would begin to see the base levels of the traces begin to drop. I opened up the UPS box and took out the 12 volt 5 amp/hr battery an replaced it with a regular car battery. I could probably go for a few days now. Angel At 10:05 AM 01/19/1999 -0800, you wrote: >Hi all -- > >I noticed that CompUSA (in Southern California, at least) has a 300 watt >Uninterruptable Power Supply on sale for $80 this week. This could make a >relatively inexpensive backup power supply for home-made seismometers. The >ad doesn't say how long it will provide that amount of power. > >As a reference, my seismometer electronics and computer running SDR consume >about 40 watts without the monitor. > > >Karl Cunningham >La Mesa, CA. >PSN station #40 >karlc@....... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Re: UPS's Date: Tue, 19 Jan 1999 18:16:03 -0400 Angel I could kiss you for this idea. I have a 1200VA UPS sitting around with a bad battery. We have frequent power outages down here and sometimes it goes for hours. NAPA, here I come. Wayne Angel Rodriguez wrote: > Hi All, > > I use a 325 VA UPS much like the one Karl mentions and it worked well for > about 30 minutes (no monitor). Then I would begin to see the base levels of > the traces begin to drop. I opened up the UPS box and took out the 12 volt > 5 amp/hr battery an replaced it with a regular car battery. I could > probably go for a few days now. > > Angel _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: JIm Hannon Subject: Re: UPS's Date: Tue, 19 Jan 1999 17:12:55 -0600 Wayne Abraham J73WA wrote: > Angel > > I could kiss you for this idea. I have a 1200VA UPS sitting around with a bad > battery. We have frequent power outages down here and sometimes it goes for > hours. NAPA, here I come. > > Wayne > > Angel Rodriguez wrote: > > > Hi All, > > > > I use a 325 VA UPS much like the one Karl mentions and it worked well for > > about 30 minutes (no monitor). Then I would begin to see the base levels of > > the traces begin to drop. I opened up the UPS box and took out the 12 volt > > 5 amp/hr battery an replaced it with a regular car battery. I could > > probably go for a few days now. > > > > Angel > > __ If you can get it I would reccomend a deep discharge rated battery like a trolling motor (marine) battery rather than a car battery. You will get a longer useful life from a battery constructed for deep discharge. We are getting a Trace Engineering inverter and 24 volts worth deep discharge batteries here, to back up the power to run my heating system. Things get a little tense when the power goes out at -20 F. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Mark Robinson" Subject: Re: UPS's Date: Wed, 20 Jan 1999 12:16:57 +1300 HI folks, In general I would recommend the use of true sinewave inverters for seismo applications. THe square wave Pulse Width Modulated ones generate a ton of hash which is likely to cause intereference to the sensitive electronics. UPSs are generally designed to work with the smaller battery. Connecting a larger one may take you beyond the duty cycle the device was designed for. Bolt some more metal to the switching transistor heatsinks or add a fan. have fun Mark G Robinson | ZL2TOD | other@............... Box 8770, Auckland 1035, New Zealand Phone +64-9-846-3296 | Fax +64-9-849-7408 ------------------------------------------------ 20 Jan 1936 King George V of England died. 20 Jan 1953 Eisenhower sworn in as 34th U.S. President. 20 Jan 1991 Soviet Black Beret Police storm Latvian Interior Ministry building. ----- Original Message ----- From: Karl Cunningham To: Sent: Wednesday, 20 January 1999 07:05 Subject: UPS's >Hi all -- > >I noticed that CompUSA (in Southern California, at least) has a 300 watt >Uninterruptable Power Supply on sale for $80 this week. This could make a >relatively inexpensive backup power supply for home-made seismometers. The >ad doesn't say how long it will provide that amount of power. > >As a reference, my seismometer electronics and computer running SDR consume >about 40 watts without the monitor. > > >Karl Cunningham >La Mesa, CA. >PSN station #40 >karlc@....... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: USGS Geologic Division Subject: USGS Earthquake report Date: Tue, 19 Jan 1999 22:20:01 -0600 Magnitude 6.4 earthquake near NEW IRELAND REGION, P.N.G. 4.36S, 153.16E depth 114.3km Tue Jan 19 03:35:33 1999 GMT An earthquake has occurred. Following is information provided by the National Earthquake Information Service of the USGS. This information is preliminary and subject to correction. Time: GMT Tue Jan 19 03:35:33 1999 (EST Mon Jan 18 22:35:33 1999) (PST Mon Jan 18 19:35:33 1999) Magnitude: 6.4, determined using its surface wave characteristics Epicenter: 4.36S, 153.16E (NEW IRELAND REGION, P.N.G.) Precision: B, where A is fine and D is coarse. Depth of focus: 114.3km below sea level at the epicenter. For a map showing this event, please consult the web page Further info can be obtained from the USGS National Earthquake Information Center at or the USGS home page at You will continue to receive messages like this when earthquakes occur that have magnitude 5.0 or more in the continental US, Alaska, and Hawaii, and 6.0 or more anywhere in the world The subscription form for this service is at If you do not wish to receive these messages, please visit that subscription form, enter your email address, and select "unsubscribe". If that does not stop the messages, please send email to info@................ -- U.S. Geological Survey -- Science for a Changing World _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: UPS info Date: Wed, 20 Jan 1999 01:18:33 -0600 (CST) Some comments about increasing the support capacity of UPS systems: This is generally feasible; the actual power capacity (watts or VA) is fixed by the inverter, but the time it can support a load can be extended considerably by adding external batteries. All the batteries MUST be of the same type, capacity, manufacturer, date, etc, for them to parallel properly, which usually means discarding the original internal small gell-cell battery. But if the original battery was 5 ampere-hours, using a 50 or 100 AH marine battery will require 10 to 20 times longer to recharge, which might mean several days after an extended AC outage, since the charger in switched UPS systems is usually quite small, like about 5% of the full load current. Always use fuses when connecting batteries in parallel, preferably the low-voltage "rectifier" or DC type fuses. If a cell shorts in one battery in parallel with another, the short will dissipate all the energy of the paralleled batteries. Here is some previously posted information: We operate several types of UPS systems at the seismic observatory and at the major remote sites. Some have the 1 killowatt "Best" brand units, which are switched systems: the inverter is switched on and connected to the load only when the AC line fails, like most computer UPS boxes. For these, we parallel the internal battery (ies) with external batteries, using low voltage, low resistance "rectifier" fuses for protection. The large DC battery connectors are helpful (Grainger 6A070 series, about $10). It is VERY important that all the batteries that are connected in parallel be of exactly the same type and age, even if this means replacing the original internal battery with a new one, or simply omitting it. We use the 90 amp-hr Delco photo- voltaic batteries, or else the deep-discharge "marine" type batteries connected in a 48 volt, 200 ampere-hour configuration. With continuous float charging and periodic equalize cycles, they still only last 3 to 4 years. We have also made some hybrid UPS systems using commercial 1kw precision inverters (by TOPAZ), large 3-phase DC supplies (13.6V at 250 amps), and large "stationary" batteries by Exide. These are 660 amp/hr cells with high calcium plates, which are used in stationary service like telephone exchanges and backup power for mine hoists. They are guaranteed for 20 years. With 660 Ah cells, we get about 6 hours of UPS power at the 1kw level. (We can get the generator going by then). (Also, we limit our loads to about 750 watts). Our loads operate continuously from these inverters, so the AC-DC supply has to provide its input (like 100 Amps) plus re-charge the batteries in a resonable time. It is also precise enough to be set within 10 millivolts to properly float the batteries. So with the batteries always connected to the inverter, there is no power transfer needed when the AC goes out. However, we do have a "failsafe" arrangement that connects the external loads to the AC line in the rare event that the inverter fails. We also have a pair of digital timers that force an "equalizing" charge voltage for several hours once a month by switching on a different resistor in the AC-DC supply voltage feedback reference. These large systems weigh about 1500 lbs. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Taber Subject: re: Little quakes from distant BIG quakes Date: Thu, 21 Jan 1999 16:22:33 +1300 (NZDT) Bonnie wrote: > > Hi, I believe that there were two smaller quakes just before the 8.3 > quake in 1857 at Fort Tajone. Sorry about the spelling. I'm not familiar with what happened before the Fort Tejon earthquake, but it sounds like you might be describing foreshocks. Though the definition is a bit arbitrary, a foreshock is usually defined as being near and perhaps on the same fault as the mainshock, whereas in the case of distant triggering, the earthquakes may be on completely different fault systems. Nearby earthquakes do seem to trigger each other. Once an earthquake has occurred, the odds of another earthquake of the same or larger magnitude are higher than if the first quake hadn't happened. The trick is to figure out which earthquakes are foreshocks, and there has been a lot of debate as to how or if that is possible. Cheers, John _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: re: Little quakes from distant BIG quakes Date: Wed, 20 Jan 1999 21:13:42 -0700 (MST) On Thu, 21 Jan 1999, John Taber wrote: > Nearby earthquakes do seem to trigger each other. Once an > earthquake has occurred, the odds of another earthquake of the > same or larger magnitude are higher than if the first quake hadn't > happened. The trick is to figure out which earthquakes are > foreshocks, and there has been a lot of debate as to how or if > that is possible. Indeed, some even claim that a period of low seismic activity preceeds major earthquakes, but if you plot, for example, the time of earthquake occurrences as a function of the distance along the San Andreas fault (within a certain distance) you will see many blank spots which are not followed by large quakes, and only a few that are... Recent attempts by Chinese seismologists based on foreshocks to predict large quakes were attempted, but a recent group sent over to China to evaluate their method seems to think that their method is not as good as they say it is. Another thing to consider is that different portions of different faults behave quite differently. Consider Landers, which has the most peculiar aftershock distributions (decaying sinusoidal activity)... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Bonnie Subject: taber@............. Date: Wed, 20 Jan 1999 20:40:04 -0600 Little quakes from distant BIG quakes Hi John, Thanks so much for writing. Foreshocks and aftershocks are indeed interesting. I have always wondered how far in advance a quake must strike (a smaller one before a big one) before it can be called a foreshock to a larger event. Also, how long do aftershocks go on after the main event has occurred? I guess I am full of questions. Thanks. Bonnie the crafty crafter Net-Tamer V 1.11.2 - Registered _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Roger Griggs Subject: Re: UPS's Date: Wed, 20 Jan 1999 22:14:29 -0800 At 06:16 PM 1/19/99 -0400, you wrote: >I could kiss you for this idea. I have a 1200VA UPS sitting around with a bad >battery. We have frequent power outages down here and sometimes it goes for >hours. NAPA, here I come. > >Wayne Wayne, Would your UPS happen to be a APCC 1200VX? If it is, we have several of these old units still in operation in our Electric Transmission control centers. I have replaced the batteries many times in the past few years. A great source for replacement batteries is AMP KING BATTERY Co. in San Francisco. The 1200VA unit takes two Powersonic PS-12180 18 amp hour batteries. Last year we picked up a dozen or so for $58 apiece. Be sure to obtain a Maintenance Manual for your particular unit so that it can be re-calibrated with the new batteries. You have to reset and test the drop out voltage levels, output freq and output voltage. I have seen these shift over time. As far as using car batteries for a UPS, I would be quite hesitant. Car batteries are not made for UPS service. You need sealed lead acid, deep cycle types. And definetly put fuses between paralled units. You cannot believe the damage a shorted battery can cause not to mention the deadly acid that can be sprayed in all directions if they blow. Roger _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Finke, John E." Subject: RE: taber@............. Date: Thu, 21 Jan 1999 13:58:08 -0500 I'm sure that the number of aftershocks and time following the larger event vary for each event based on several seismological factors. In the central United States, however, four extreme events occurred in late 1811 to 1812 that triggered aftershocks ranging from several hundred to a couple thousand over a period of several months to several years depending on which author you read. Again this is an extreme case. At least one of these earthquakes is believed to be the largest ever in the United States followed by the 1964 Alaskan earthquake. > -----Original Message----- > From: Bonnie [SMTP:bschafer@.......... > Sent: Wednesday, January 20, 1999 8:40 PM > To: psn-l@.............. > Subject: taber@............. > > Little quakes from distant BIG quakes > > Hi John, > > Thanks so much for writing. > > Foreshocks and aftershocks are indeed interesting. I have always > wondered how far in advance a quake must strike (a smaller one before a > big one) before it can be called a foreshock to a larger event. Also, > how long do aftershocks go on after the main event has occurred? > > I guess I am full of questions. Thanks. > > > Bonnie > the crafty crafter > > Net-Tamer V 1.11.2 - Registered > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: horizontal VBBs Date: Thu, 21 Jan 1999 13:38:36 -0600 (CST) Barry, Regarding your question about making a horizontal VBB sensor: The transfer function will work for any configuration of the mass movement: there is nothing in it that "knows" what the direction of the restoring force is, either vertical or horizontal. Just as the vertical only needs to know what the mechanical period is, so does a horizontal configuration. And if the period is reasonably long, the damping term will be mostly controlled by the proportional feedback resistor, which is why commercial VBB sensors are calibrated at a condition of "indifferent" equilibrium, or very long period. Also, it is worth noting that the triple VBB feedback will work quite well with the Lehman or S-G horizontal pendulums if they are equipped with a proper displacement transducer and feedback coil. This is one sure way to obtain a defined and calibrated response from these instruments. I have recently done some work on the feedback schematics to simplify things. One improvement is to eliminate the instrumentaion amplifier used for the integrator: a single low-pass filter on the quad amplifier circuit card works fine. THis card has a terminal strip that allows for mounting the feedback components as well as the high-pass output capacitors. THis allows an external multi-pole switch to select the feedback components for any effective period, which includes a "1-second" period for adjusting the seis or zeroing it without having to wait out a long integration time. For this, the feedback capacitor C is NOT changed, since this changes the output signal level in the flat portion of the response curve; (the output is the value of k = 1/(G*C), where G = Gn/M, Gn being the feedback coil constant, M is the mass; the units DO work out to Volts*seconds/meter). I will try to post the revised schematics tomorrow. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Bonnie Subject: Finke@........... Date: Thu, 21 Jan 1999 21:24:06 -0600 taber@............. Hi, thank you so much for writing and answering my questions. I really appreciate it. Bonnie the crafty crafter Net-Tamer V 1.11.2 - Registered _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: taber@............. Date: Thu, 21 Jan 1999 23:55:44 -0700 (MST) On Wed, 20 Jan 1999, Bonnie wrote: > Foreshocks and aftershocks are indeed interesting. I have always > wondered how far in advance a quake must strike (a smaller one before a > big one) before it can be called a foreshock to a larger event. Also, > how long do aftershocks go on after the main event has occurred? > I guess I am full of questions. Thanks. > Bonnie > the crafty crafter Bonnie, The definition of an aftershock or foreshock is arbitrary. Usually researchers will define the events in terms of: A) The distance from the mainshock (usually less than 50 km) B) The time from the main shock (any where from seconds to several years) Aftershocks are usually given a wider range than foreshocks, at least that I have seen. Aftershocks have been suggested to follow a decay rule called Omori's Law, however most aftershocks do not fit this model, nor can aftershock seqences be characterized according to parameters given in the model. Omori's Law only works for certain special areas. Other areas are very strange in terms of the aftershock sequence... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dan" Subject: Re: UPS info Date: Fri, 22 Jan 1999 10:06:02 -0800 You can get a longer battery life, if you use the batteries in series, I.e.. 6 and 6 for 12 or individual cells 2 volt 300 amp each for 12 , In a series config you will have more plate surface area, spreading out the amperage taken per plate and giving a lot longer discharge time giving , cost is less than finding a matched pair , only need to find same voltage and amp hour out. If you use in parallel, the specific gravity and internal resistance of each batt must be matched . not the case with series batt, look for a battery supply house in your area, and buy one made for solar use 6 volt 380 amp hour is about 180 dollars each Dan swanson -----Original Message----- From: S-T Morrissey To: psn-l@............. Date: Tuesday, January 19, 1999 23:19 Subject: UPS info > >Some comments about increasing the support capacity of UPS systems: >This is generally feasible; the actual power capacity (watts or VA) >is fixed by the inverter, but the time it can support a load can >be extended considerably by adding external batteries. All the >batteries MUST be of the same type, capacity, manufacturer, date, etc, >for them to parallel properly, which usually means discarding the >original internal small gell-cell battery. But if the original battery >was 5 ampere-hours, using a 50 or 100 AH marine battery will require >10 to 20 times longer to recharge, which might mean several days after >an extended AC outage, since the charger in switched UPS systems is usually >quite small, like about 5% of the full load current. > >Always use fuses when connecting batteries in parallel, preferably the >low-voltage "rectifier" or DC type fuses. If a cell shorts in one battery >in parallel with another, the short will dissipate all the energy of >the paralleled batteries. > >Here is some previously posted information: > >We operate several types of UPS systems at the seismic observatory and at >the major remote sites. Some have the 1 killowatt "Best" brand units, >which are switched systems: the inverter is switched on and connected >to the load only when the AC line fails, like most computer UPS boxes. >For these, we parallel the internal battery (ies) with external batteries, >using low voltage, low resistance "rectifier" fuses for protection. >The large DC battery connectors are helpful (Grainger 6A070 series, >about $10). It is VERY important that all the batteries that are >connected in parallel be of exactly the same type and age, even >if this means replacing the original internal battery with a new >one, or simply omitting it. We use the 90 amp-hr Delco photo- >voltaic batteries, or else the deep-discharge "marine" type >batteries connected in a 48 volt, 200 ampere-hour configuration. >With continuous float charging and periodic equalize cycles, >they still only last 3 to 4 years. > >We have also made some hybrid UPS systems using commercial 1kw precision >inverters (by TOPAZ), large 3-phase DC supplies (13.6V at 250 amps), and >large "stationary" batteries by Exide. These are 660 amp/hr cells >with high calcium plates, which are used in stationary service like >telephone exchanges and backup power for mine hoists. They are >guaranteed for 20 years. With 660 Ah cells, we get about 6 hours >of UPS power at the 1kw level. (We can get the generator going by then). >(Also, we limit our loads to about 750 watts). > >Our loads operate continuously from these inverters, so the AC-DC >supply has to provide its input (like 100 Amps) plus re-charge the >batteries in a resonable time. It is also precise enough to be set >within 10 millivolts to properly float the batteries. So with the >batteries always connected to the inverter, there is no power >transfer needed when the AC goes out. However, we do have a >"failsafe" arrangement that connects the external loads to the >AC line in the rare event that the inverter fails. We also have >a pair of digital timers that force an "equalizing" charge voltage >for several hours once a month by switching on a different resistor >in the AC-DC supply voltage feedback reference. These large >systems weigh about 1500 lbs. > >Regards, >Sean-Thomas > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Bonnie Subject: hernlund@....... Date: Fri, 22 Jan 1999 23:43:04 -0600 taber@............. Hi John, Thank you so much for patiently answering my questions. I only have one more--honest! bbg What makes a fault that has lain dormant for many years suddenly come to life? I am thinking of the fault responsibile for the '71 quake. It really didn't do too much up until that time in fact I heard that geologists were very surprised at its' sudden activity. Thanks again. Bonnie the crafty crafter Net-Tamer V 1.11.2 - Registered _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: UPS info Date: Sat, 23 Jan 1999 09:09:10 -0800 Dan et al Speaking of solar-- I have been wondering about solar charging for my system. Does one have the same problem with matching solar cells in parallel as with batteries? Do they have to be matched? I'm not sure how they are rated, by volts or power or current. I assume applying a back voltage on a cell will not hurt but, will only the higher voltage cell be working at any one time? ie will the current be close to double for parallel connection? Barry Dan wrote: > You can get a longer battery life, if you use the batteries in series, > I.e.. 6 and 6 for 12 or individual cells 2 volt 300 amp each for 12 , In > a series config you will have more plate surface area, spreading out the > amperage taken per plate and giving a lot longer discharge time giving , > cost is less than finding a matched pair , only need to find same voltage > and amp hour out. If you use in parallel, the specific gravity and > internal resistance of each batt must be matched . not the case with series > batt, > look for a battery supply house in your area, and buy one made for solar > use 6 volt 380 amp hour is about 180 dollars each > Dan swanson _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: UPS info Date: Sat, 23 Jan 1999 11:30:44 -0700 barry lotz wrote: > > Dan et al > Speaking of solar-- I have been wondering about solar charging for my > system. Does one have the same problem with matching solar cells in parallel as > with batteries? Do they have to be matched? Don't know. > I'm not sure how they are rated, by volts or power or current. Watts. > ie will the current be close to double for parallel connection? I think so. I wish I could afford to install a bunch of solar cells, but they're pretty expensive. I found a site with a reasonable attitude about them. http://www.windsun.com/ They're one of the few sites with actual prices and information. Kyocera and Siemens also have web sites with information about their panels. Just found this quote by accident: "In this diagram, the two diodes at the END are the blocking diodes, which prevent reverse current flow at night. These are seldom needed in systems with controllers, as nearly all charge controllers have a built in method of preventing reverse current." I also had a bookmark to another site where a guy powered his Icom 706-II with a solar cell and a battery charger. The neat thing was that it was portable and there was no AC involved. In other words no expensive inverters. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: solar panel info Date: Sat, 23 Jan 1999 13:57:28 -0600 (CST) Barry, Some info on solar panels: The mid-day sun shines at mid-lattitudes at about 1 killowatt per square meter. SO a solar panel with 10% efficiency (a quality panel), can produce 100 watts from a large 3 ft x 4 ft panel. More affordable panels, made from "amorphous" rather than crystaline cells, are about half as efficient, but cost as little as 1/5 the cost. Panels used for satellites can approach 20% efficiency. Recently an innovation to "recycle" the portions of cyrstaline silicone ingots that are unsuitable for semiconductor production may help bring down the cost of the more efficient cells. Panels are usually rated for power output in watts, with a 20 watt SOLAREX panel being about 24" x 30". The internal cell connections are set up for a nominal "12 volt" output by proper series and parallel connections to produce up to 2 amperes (for the 20 w panel). The actual output voltage will range above 18 volts, so a voltage regulator is needed for long term charging of batteries, and it must provide protection from reverse current from the battery into the panel. A MAJOR problem arises when large panels are connected in parallel because of the fact that when no light is shining on a portion of the panel (due to leaves or shadows or nightfall, etc), the cells become un-polarized and act as low value resistors that effectively short out part of the panel, so a fully illuminated parallel connected panel can cause a damaging reverse current in the shadowed panel. So low loss (Schottky) diodes are used in series with each panel when they are connected in parallel. Make sure that the battery has a fuse to protect things if the regulator and/or diodes fail (or the operator makes a stupid connection). Another risk with large panels is when they are connected in series for "line voltage" or 120 volt battery/inverter power systems. The voltage can suddenly go from nil to lethal if a cloud moves away, so the panel circuitry must always be considered as "live and dangerous". For sizing a panel for a given load, we have found that a 20-watt panel, charging a 90 ampere-hour 12 volt deep-discharge or photo-voltaic battery (float charged at 13.6 v), can provide reliable continuous operation of a seismic telemetry station drawing a load of 0.1 amperes (at 13.6 volts). But near the winter solstice or minimum of the length of the day, it barely makes it, especially if snow covers the panel for more than a day. This latter problem can be reduced by mounting the panel almost vertically, which we do in Alaska, where we need to get the most from the low sun angles in winter. OF course, as the battery ages, the support time shortens; the useful life of a good sealed battery is about 3 to 4 years. A common maintenance problem in some areas is with large birds roosting on the panels and dumping droppings on them. We remedy this with a "bird bar", which is an aluminum angle mounted across the top of the panel with stainless steel nails driven through it so that they point upward in a row that the birds will not roost on. In some areas, we have had problems with people target shooting at the panels. We try to minimize the damage by providing a 3/4" treated plywood cover on the back of the solar panel; it can actually be fit inside the aluminum frame of the SOLAREX panel. This can cause excessive heating of the panel, so ventilation holes must be provided along the bottom and top of the wood cover. I have not priced panels recently; the 20 watt SOLAREX cost $180 several years ago. Regards, Sean-Thomas ............ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Karl Cunningham Subject: Re: UPS info Date: Sat, 23 Jan 1999 12:13:27 -0800 Barry -- Solar panels are for the most part constant-current devices, with the current being more or less proportional to the incoming solar flux. The ratings go something like 12 volts at 2.4 amps. The voltage is a nominal voltage, and the current is (for reputable companies) rated assuming 1000 watts/meter^2 of incoming solar flux. You can expect to get this amount of flux at noon in mid latitudes on a bright clear day. A panel with a nominal 12-volt rating will put out approximately the same current over a range from zero to about 19 volts, where it starts to drop off. The peak POWER output is at about 19 volts. When you connect them directly to a 12-volt battery, there will be a constant current going into the battery so you need some voltage limit to avoid overcharging the battery. A good (fairly fast) way to recharge a lead-acid battery (liquid or gel electrolyte) is to charge at constant current up to a certain voltage, then change to constant voltage for "float." This float voltage is what the battery can tolerate for extended periods of time. The voltage levels depend on the chemistry of the particular battery involved. This charging scheme is well suited to solar charging since all you need to do is sense the high-rate voltage threshold and introduce a voltage limiter to keep from overcharging the battery. You should have a diode between the solar panel and the battery to prevent reverse current flow for night time or clouds. Solar panels are available through surplus outlets for $4 per watt, somtimes much less. The early ones had a lifetime of about 20 years out in the sun so be careful of those. Before you buy, take the panel out in the sun and measure its open-circuit voltage and short-circuit current. Surplus panels sometimes have open or shorted cells. Shorted ones are no problem, but if there are any open ones, you will have to jumper them to use the panel. In either case you'll get less output. Hope this helps, Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... At 09:09 AM 1/23/99 -0800, you wrote: > Dan et al > Speaking of solar-- I have been wondering about solar charging for my >system. Does one have the same problem with matching solar cells in parallel as >with batteries? Do they have to be matched? I'm not sure how they are rated, by >volts or power or current. I assume applying a back voltage on a cell will not >hurt but, will only the higher voltage cell be working at any one time? ie will >the current be close to double for parallel connection? > >Barry > >Dan wrote: > >> You can get a longer battery life, if you use the batteries in series, >> I.e.. 6 and 6 for 12 or individual cells 2 volt 300 amp each for 12 , In >> a series config you will have more plate surface area, spreading out the >> amperage taken per plate and giving a lot longer discharge time giving , >> cost is less than finding a matched pair , only need to find same voltage >> and amp hour out. If you use in parallel, the specific gravity and >> internal resistance of each batt must be matched . not the case with series >> batt, >> look for a battery supply house in your area, and buy one made for solar >> use 6 volt 380 amp hour is about 180 dollars each >> Dan swanson > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dan" Subject: Re: UPS info Date: Sat, 23 Jan 1999 12:57:06 -0800 >barry lotz wrote: >> >> Dan et al >> Speaking of solar-- I have been wondering about solar charging for my >> system. Does one have the same problem with matching solar cells in parallel as >> with batteries? Do they have to be matched? > >Don't know. No, to match a solar cell, you only need to have max watt out same, as voltage and current will vary with amount of light, does no even have to be same brand >> I'm not sure how they are rated, by volts or power or current. >Watts. Yes, the watts given for a cell are based on full sun light, at high noon. The max energey deliverd by sun is 1000 watts per square meter. In califorina, your usable light is 4 to 5 hours per day for solar calcuting purposes, This is why you need to have so many. If you use the modules l with battery , the module rated for 17 volts will put out less than its rated output , when used with batterys the working voltage will be betwween 12 and 15 . Example a 50 watt module working at 13.0 volts will produce only 39 watts. >> ie will the current be close to double for parallel connection? If both cell share the same amount of light at the same time it should be close >I think so. >I wish I could afford to install a bunch of solar cells, but they're >pretty expensive .. They are not cheap, about 300.00 for 50 watts. I live in san francisco, out in the by the beach, So I chose to use wind power, A new model, thats whisper quite, mounted 3 feet above my roof. puts out 12 or 24 volt- 500 watt at 28mph, I use to in parrell to get 200 watts at 9mph, which is over most of day and night. the cost is 12 or 24 volt 500 watt for <400.00 I found a site with a reasonable attitude about them. >http://www.windsun.com/ >They're one of the few sites with actual prices and information. when you buy modules, make sure they have diodes between each cell in module, as this will keep the module producing power, when a cloud go over head or leaves lands on module blocking light on a cell. Without doides the cell will stop output, and if you have more than one panel in parell or series it will start distchharge into blocked one. >Kyocera and Siemens also have web sites with information about their >panels. > >Just found this quote by accident: >"In this diagram, the two diodes at the END are the blocking diodes, >which prevent reverse current flow at night. These are seldom needed in>systems with controllers, as nearly all charge controllers have a built >in method of preventing reverse current." > blocking diodes are used to prevent clouds blocking one module and and causing a discharge from other modules, some hook ups put 2 or 3 moduels in series or parrell before the controller come into play. because of voltage drop in each connect to controller .. >I also had a bookmark to another site where a guy powered his Icom >706-II with a solar cell and a battery charger. The neat thing was that >it was portable and there was no AC involved. In other words no >expensive inverters. you can get small panels rated for 15.6volt 11 watt 7 to 800 ma for about 120 or less good for handi talki. for 706 you would need to figure how long of transmit time will be needed, and recive current . I am not sure what the curent on a 706 is, 100 watt output? Dan >,Greg > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: solar cells Date: Sat, 23 Jan 1999 13:07:35 -0800 Greg,Sean Thomas & Karl Thanks for the info. I have been running a homemade solar charging circuit that I got from a back issue of Nuts&Volts when they had a solar power series of articles. I will add some more panels with low drop diodes. I have been using Horowitz & Hill's recommendations on battery charging. Where I live, there are alot of trees and therefore the sun is periodic. I ran a controller once that kept track of power and time over a 24hr period and one 12"x12" panel was not enough to keep up with 5vts@...... It is an inexpensive panel. I forget what the rated wattage is. With multiple panels I can orientate them to get more current as the sun chifts position. There is a company back east that sells a 386 SBC that runs @ 0.1 watt. I hope to incorporate this in a field unit. I would use a 8 bit processor but some of the math on my data acquisition program (digital filter & FFT) run much slower on an 8 bit unit. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dan" Subject: Fw: UPS info correction Date: Sat, 23 Jan 1999 09:40:08 -0800 Please disregard my last message about ups info, in trying to answer my many email in a short amount of time, I make drafts first before sending, then I go back later and edit or just delete. In this case, my email program has the file button just above the send button about 1/8". On my laptop I used the buitl in stick mouse and and my thumb hit the right mouse pad, and away it went. I need to find either a better way, or put a stop send switch on modem line to stop send. Thanks dan _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dan" Subject: Re: UPS info Date: Sat, 23 Jan 1999 15:28:36 -0800 I do not know anymore, who is taking to who. The messages I received and sent, are not what I see coming back. The original and questions are not same nor my answer to them I should probably stay out of this one Dan -----Original Message----- From: Karl Cunningham To: PSN-L Mailing List Date: Saturday, January 23, 1999 12:14 Subject: Re: UPS info >Barry -- > >Solar panels are for the most part constant-current devices, with the >current being more or less proportional to the incoming solar flux. The >ratings go something like 12 volts at 2.4 amps. The voltage is a nominal >voltage, and the current is (for reputable companies) rated assuming 1000 >watts/meter^2 of incoming solar flux. You can expect to get this amount of >flux at noon in mid latitudes on a bright clear day. > >A panel with a nominal 12-volt rating will put out approximately the same >current over a range from zero to about 19 volts, where it starts to drop >off. The peak POWER output is at about 19 volts. When you connect them >directly to a 12-volt battery, there will be a constant current going into >the battery so you need some voltage limit to avoid overcharging the battery. > >A good (fairly fast) way to recharge a lead-acid battery (liquid or gel >electrolyte) is to charge at constant current up to a certain voltage, then >change to constant voltage for "float." This float voltage is what the >battery can tolerate for extended periods of time. The voltage levels >depend on the chemistry of the particular battery involved. This charging >scheme is well suited to solar charging since all you need to do is sense >the high-rate voltage threshold and introduce a voltage limiter to keep >from overcharging the battery. > >You should have a diode between the solar panel and the battery to prevent >reverse current flow for night time or clouds. > >Solar panels are available through surplus outlets for $4 per watt, >somtimes much less. The early ones had a lifetime of about 20 years out in >the sun so be careful of those. Before you buy, take the panel out in the >sun and measure its open-circuit voltage and short-circuit current. >Surplus panels sometimes have open or shorted cells. Shorted ones are no >problem, but if there are any open ones, you will have to jumper them to >use the panel. In either case you'll get less output. > >Hope this helps, > >Karl Cunningham >La Mesa, CA. >PSN Station #40 >karlc@....... > > >At 09:09 AM 1/23/99 -0800, you wrote: >> Dan et al >> Speaking of solar-- I have been wondering about solar charging for my >>system. Does one have the same problem with matching solar cells in >parallel as >>with batteries? Do they have to be matched? I'm not sure how they are >rated, by >>volts or power or current. I assume applying a back voltage on a cell will >not >>hurt but, will only the higher voltage cell be working at any one time? ie >will >>the current be close to double for parallel connection? >> >>Barry >> >>Dan wrote: >> >>> You can get a longer battery life, if you use the batteries in series, >>> I.e.. 6 and 6 for 12 or individual cells 2 volt 300 amp each for 12 , In >>> a series config you will have more plate surface area, spreading out the >>> amperage taken per plate and giving a lot longer discharge time giving , >>> cost is less than finding a matched pair , only need to find same voltage >>> and amp hour out. If you use in parallel, the specific gravity and >>> internal resistance of each batt must be matched . not the case with >series >>> batt, >>> look for a battery supply house in your area, and buy one made for solar >>> use 6 volt 380 amp hour is about 180 dollars each >>> Dan swanson >> >> >>_____________________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email listserver@.............. with the body of the >>message: leave PSN-L >> >> > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: hernlund@....... Date: Sun, 24 Jan 1999 00:15:53 -0700 (MST) On Fri, 22 Jan 1999, Bonnie wrote: > What makes a fault that has lain dormant for many years suddenly come to > life? I am thinking of the fault responsibile for the '71 quake. It > really didn't do too much up until that time in fact I heard that > geologists were very surprised at its' sudden activity. Bonnie, Really, all anyone can say about that is the fault moves when the stresses in the material containing the fault exceeds the frictional strength of the fault itself. The stress is not constant, because other activity in the same region changes the balance of forces constantly. Also, not all activity along a fault results in earthquakes. At times, the fault moves very slowly (creep) and other times the material along the fault is deforming by folding up into low hills or troughs. Also, water may get into the fault and make it more slippery. Different rock types along different portions of the fault provide different frictional resistance to slipping. With all of the complexities surrounding faults almost any kind of behavior can occur. Usually, there are theoretical limits as to how strong the fault can be and how long it would take for the movement of the plates to accumulate enough stress to cause an earthquake. But accurate measurements on non-earthquake processes that help remove stress are only being applied in several locations, so we don't really always know how it works on other areas. Add to the complexity the probability that these complex processes surrounding the fault are always changing and cannot usually be well studied by paleoseismic methods to aid in forecasting because by the time we figured out how the fault worked at one point in time it probably has changed... So when you hear that geologists were surprised over some occurrence in seismology, then you shouldn't be surprised that they are surprised... :-) Scientists have to sell their progress to institutions and bureaucrats in order to have money that funds their research. So it is hard to know if what you hear in the press is the whole truth. This is why peer-reviewed science is so important. This is the preferred medium for letting people know about your research because each submission is reviewed by other scientists who are usually jealous or fame-hungry themselves. Therefore they are quite critical, and you can believe that what you are reading in an accepted journal in a particular field is the most representative idea of what is going on in areas of science. Some institutions (including one in CA whose name I won't mention) hold big press conferences and babble an awful lot after each quake. The popular press puts out really awful stories based on these conferences because the articles are not peer-reviewed. Persons who criticize this behavior could be called jealous themselves I suppose. Science is such a human event! Anyhow, if you have any further questions Bonnie, you may want to e-mail me directly at hernlund@....... instead of posting to the PSN-L mailing list. Some people on the list might not like to see their e-mail cluttered up too much with stuff about which they are already familiar... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Taber Subject: Re: foreshocks and quiet faults Date: Mon, 25 Jan 1999 13:00:36 +1300 (NZDT) Bonnie wrote: > Foreshocks and aftershocks are indeed interesting. I have always > wondered how far in advance a quake must strike (a smaller one before a > big one) before it can be called a foreshock to a larger event. Also, > how long do aftershocks go on after the main event has occurred? > As John and John have said, foreshocks are arbitrarily defined as some relatively short time (I think usually less than a few months) before the main shock, but it is possible to relate swarms of small earthquakes to larger earthquakes that happen years later. A seismologist here (Frank Evison) has been testing a hypothesis that a group of earthquakes that are clustered in space and time can be used to predict a larger earthquake several years later. For example a group of 10 earthquakes with a maximum magnitude of around 4 were used to forecast a M7 earthquake 4 years later. The method is still being tested and it can't predict the exact time, but can give a general idea of when a big earthquake is likely. >What makes a fault that has lain dormant for many years suddenly come to >life? A fault can be considered to be "active" even though it hasn't moved in a few thousand years. A volcano may be dormant in that there has been no magma recently moving to the surface, but stresses are building up continuously on "quiet" faults. The two sides of the fault may be stuck together, but the rocks nearby are being compressed or stretched just like a rubber ball. This deformation can be measured by GPS receivers. I think it is fairly common for major faults to have essentially no small earthquakes for much of the time between major earthquakes. For example in New Zealand, the 2 faults that are of the greatest concern (the Wellington Fault and the Alpine Fault) appear to have no earthquake activity at the moment. John Taber _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: [Fwd: Leased-line digital communications information needed] Date: Sun, 24 Jan 1999 22:43:19 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". To CNSS technical types: I am looking to review the technology being used for telemetry of digital data over voice-grade continuous circuits such as leased phone lines, hard-wire, or microwave circuits. We are currently using some Motorola modems for 9 remote seismic stations and need to get more but want to make sure we know about all possiblities and use the most effective available. Anyone with information about such things, please send it to me and I will make a summary of it to post on the CNSS WEB pages for the use by all. FYI our current most demanding use is: telemetry of 6 seismic channels of 4-byte samples at 100 samples per second which is about 24 Kbaud rate (though very compressible since at least one of every four bytes is always the same). We are currently using: Motorola V.3400 model modems in 2wire and 4wire leased line modes. These have been costing about $350 for used-refurbished units per modem. These modems are rated at V.34 33.6 with compression and error checking but no retransmission. We use them with DCE speed of 28,800 baud and a DTE speed of 38,400 baud. All error checking and compression is handled by the modems. They have been fairly reliable but seem particularly sensitive to line level changes and sometimes drop off-line for no obvious reason and must be power cycled at one end to bring them back on line. Steve Malone E-mail: steve@...................... Geophysics Program Phone: (206) 685-3811 University of Washington FAX: (206)543-0489 Box 351650 Office: ATG-226 Seattle, WA 98195 http://www.geophys.washington.edu From: KACAMACHO@....... Subject: Re: foreshocks and quiet faults Date: Mon, 25 Jan 1999 10:46:43 EST I WOULD LIKE TO THANK YOU GENTLEMEN FOR TAKING TIME OUT TO INFORM US "LAY PEOPLE" WHO DO NOT HAVE THE EXTENT OF KNOWLEDGE BUT ARE VERY CURIOUS. EVEN THOUGH BONNIE ASKES ELEMENTAL QUESTIONS, AT LEAST SHE ASKS. THANKS AGAIN. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Filter IC's Date: Mon, 25 Jan 1999 18:38:23 -0800 For what it's worth Maxim has a new line of lowpass ic's with low power as well. Both 5 pole (1.2ma) and 8 pole(2ma). There is a little offset, so a DC block would be needed before gain amps. Looks interesting. They're the MAX7400 series. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: pictures (fwd) Date: Mon, 25 Jan 1999 21:30:58 -0700 (MST) ---------- Forwarded message ---------- Date: Mon, 25 Jan 1999 21:52:03 -0500 From: olde english tudor inn To: hernlund@....... Subject: pictures To whom it may concern: Hi, I am doing a science fair Project for my school and I was wondering if anyone had any pictures of a seismograph that I could get a copy of or that someone could send me over E-Mail. If anyone can help just drop me a line by E-Mail: tudorinn@.............. ! Thanks, AAP _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Website Date: Tue, 26 Jan 1999 01:34:59 -0400 PSN I am pleased to inform you of the new Dominica Public Seismic Network website. Ever since I came to you guys seeking information and help in setting up a Public Seismic Network on Dominica, you have been more than accomodating. Thank you all of you. Our new site is still under construction as I am still throwing 1001 ideas in my mind. It will continue undergoing changes until I am satisfied with the final product (which I doubt very much). Take a peek at http://www.freeyellow.com/members6/dominicapsn/ Your feedback will be appreciated. Wayne. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: Website Date: Mon, 25 Jan 1999 23:00:07 -0700 Wayne Abraham J73WA wrote: > Your feedback will be appreciated. Very very nice. Makes me want to work on my site. ;) ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Angel Rodriguez Subject: Re: pictures (fwd) Date: Tue, 26 Jan 1999 09:05:48 -0500 John, I have several pictures of my homemade stuff you can see them at=20 http://www.barriles.com/seismo/bru.html I hope they help some. I will be here today all day but then I have to go to Seattle for a meeting, I=B4m on the board of directors of REI, but I will be back in Panama on the 3rd of feb. I also have some of my local quakes including yesterdays Colombia quake on my ftp at=20 ftp://ftp.barriles.com Thanks, Angel At 09:30 PM 01/25/1999 -0700, you wrote: >---------- Forwarded message ---------- >Date: Mon, 25 Jan 1999 21:52:03 -0500 >From: olde english tudor inn >To: hernlund@....... >Subject: pictures > >To whom it may concern: =20 > Hi, I am doing a science fair Project for my school and I was >wondering if anyone had any pictures of a seismograph that I could get a >copy of or that someone could send me over E-Mail. If anyone can help >just drop me a line by E-Mail: tudorinn@.............. ! Thanks, > > AAP > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the=20 >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Norman Davis WB6SHI Subject: Re: foreshocks and quiet faults Date: Tue, 26 Jan 1999 07:11:42 -0800 Just a note. You might want to get into lower case. When your type upper case it means you are shouting. At 10:46 AM 1/25/99 EST, you wrote: >I WOULD LIKE TO THANK YOU GENTLEMEN FOR TAKING TIME OUT TO INFORM US "LAY >PEOPLE" WHO DO NOT HAVE THE EXTENT OF KNOWLEDGE BUT ARE VERY CURIOUS. EVEN >THOUGH BONNIE ASKES ELEMENTAL QUESTIONS, AT LEAST SHE ASKS. THANKS AGAIN. > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: large aleutian event Date: Thu, 28 Jan 1999 22:59:56 +1300 jst recorded (08:30 UTC 28 Jan 99) Fox Islands, aleutian islands region Mb6.5 recorded well by tony in hawaii and myself ohhh and by the way come the 14 April i will no longer be living in NZ i am shifting to just south of Madison, Wisconsin after a stop in hawaii for ~6 days to meet my girlfriend, see tony, and play in the lava etc my girlfriend and i will fly to LA have ~3 days in the LA area maybe get a chance to meet a couple of the guys before we drive through to wisconsin over the next 4 days We will be in LA from approx 19 - 22 April Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: large aleutian event Date: Thu, 28 Jan 1999 09:14:48 -0700 (MST) On Thu, 28 Jan 1999, David A. Nelson wrote: > after a stop in hawaii for ~6 days to meet my girlfriend, see tony, and > play in the lava etc my girlfriend and i will fly to LA have ~3 days in the > LA area maybe get a chance to meet a couple of the guys before we drive > through to wisconsin over the next 4 days > We will be in LA from approx 19 - 22 April > Dave Dave, If you are passing through Phoenix, let me know and I can show you around ASU if you want... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: large aleutian event Date: Thu, 28 Jan 1999 18:55:24 -0700 Dave- And without asking why you are moving from NZ to Wisconsin, you should stop by and see us (Mark Meremonte, John Lahr, Meredith Lamb, me and the NEIC) on your road trip from LA to there. Please let us know what's happening. -Edward "David A. Nelson" wrote: > jst recorded (08:30 UTC 28 Jan 99) Fox Islands, aleutian islands region > Mb6.5 recorded well by tony in hawaii and myself > > ohhh and by the way come the 14 April i will no longer be living in NZ > > i am shifting to just south of Madison, Wisconsin > > after a stop in hawaii for ~6 days to meet my girlfriend, see tony, and > play in the lava etc my girlfriend and i will fly to LA have ~3 days in the > LA area maybe get a chance to meet a couple of the guys before we drive > through to wisconsin over the next 4 days > We will be in LA from approx 19 - 22 April > > Dave > Co-ordinator: > New Zealand > Public Seismic Network > Dave A. Nelson ZL4TBN > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://www.seismicnet.com/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Fred Subject: Anyone else get that Date: Sat, 30 Jan 1999 23:43:17 -0800 Did anyone else catch the quake in Columbia. I haven't seen any threads about it ? -- How much choice did God have in constructing the Universe? If the no boundary proposal is correct, he had no freedom at all to choose initial conditions. He would have only had the freedom to choose the laws the universe obeyed. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: Re: Anyone else get that Date: Sun, 31 Jan 1999 22:54:11 +1300 At 23:43 30/01/99 -0800, you wrote: >Did anyone else catch the quake in Columbia. I haven't seen any threads >about it ? > Fred there have been plenty of event files posted for it i didn record some surface waves from it here in NZ but it wasnt worth posting for me a good # of others got excellent records Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: Dominica station now on map Date: Mon, 1 Feb 1999 20:41:20 +1300 greetings all, the Dominica station is now on the world map and in the database sorry wayne for taking so long things have been in an upheaval around this place :)) thanks for ur patience Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Rough Draft of Seismograph Theory Page Date: Mon, 01 Feb 1999 20:24:10 -0700 (MST) Hello Everyone, Because of many requests for information and general questions about seismographs from people on the internet and in my community I have decided to undertake a project that describes the way seismometers work both mathematically and graphically. This is because I can never find a good book to refer people to that ties all the concepts together. I have only covered material pertaining to simple damped seismometers, but I plan to add more material as I go eventually describing some of the mathematics of various filters, the sampling process, Fourier Analysis, and other usually advanced and scattered topics. It is only a rough draft now, but I thought the PSN would be the perfect place to ask for a review and suggestions on what has been completed thus far. If you get the chance, read through it, and e-mail me any comments/suggestions that you have. Be honest: if it sucks and doesn't make any sense at all, then let me know because you won't be the first to feel that way! ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Oops, here is the address... Date: Mon, 01 Feb 1999 20:25:22 -0700 (MST) I forgot to include the address previously! Here it is: http://www.public.asu.edu/~hernlund/seismograph/ ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: MAJ QUAKE In progress Date: Wed, 3 Feb 1999 15:05:23 +1300 0145 UTC 03 feb Maj quake in progress looks to be in sth pacific possib fiji region and M6.5 or greater Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: meredith lamb Subject: Re: MAJ QUAKE In progress Date: Tue, 02 Feb 1999 19:27:35 -0700 "David A. Nelson" wrote: > 0145 UTC 03 feb Maj quake in progress > > looks to be in sth pacific possib fiji region > > and M6.5 or greater > > Dave > Co-ordinator: > New Zealand > Public Seismic Network > Mainly just getting L waves in Denver....but possible aftershocks?? Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: MAJ QUAKE In progress Date: Tue, 02 Feb 1999 19:31:19 -0800 Dave: From Red Puma- 03Feb1999 01:13:59.3 20.2S 174.2W 33 mb=5.9 A NEI TONGA ISLANDS Barry David A. Nelson wrote: > 0145 UTC 03 feb Maj quake in progress > > looks to be in sth pacific possib fiji region > > and M6.5 or greater > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: Ms6.2 ?????????? Date: Wed, 3 Feb 1999 17:11:45 +1300 NEIC 99/02/03 01:13:57 20.20S 174.36W 33.0 6.2Ms TONGA ISLANDS wowwowo thats gotta be understated, That would make it the higest amplitude Ms6.2 I would have ever seen then hahaha my winquake whis is usually pretty close to most recent teleseisms, it is saying Ms6.7 and John H. u made similar comments in ur mail will be really interested to see the Mw for this one Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: tongan event Date: Wed, 3 Feb 1999 18:27:55 +1300 im gonna have to eat humble pie, as i hang my head in shame :) my winquake shows Ms6.2 when P and S are correctly located but at least its still showing reasonable calibration Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: New WinQuake beta release version 2.5.8 Date: Tue, 02 Feb 1999 21:58:42 -0800 Hi Everyone, Today I released a new beta version of WinQuake. This is beta version 2.5.8. I made a few changes from the last release so heres what's new. New Command Line option: Currently WinQuake (WQ) can print a file from the command line. The format is: winqk32 /p file_name I added the ability to create a gif image of the event file. The format is winqk32 /g input_file [output_file_or_dir]. The output file or directory is optional. If this argument is not supplied, WQ will us the input file name and append ".gif" too it and use this as the output name. It will show up in the same directory as the input file. If you only supply a directory, for the output, WQ will save the gif image file in the directory specified and use the input file name + gif. If you specify a file name and directory, WQ will use that as the output name and location. Local Data Directory: Under the File menu items you will see a new menu item called Local Data Directory... This is used when WQ is run on a network/file server setup. If the WQ exe is located on a server you can specify a local directory on the system that is running the program. Some of the data / config files (ending in *.dat) should be located on the local system rather then the server system. The email.dat, phase.dat and replay.dat files should all be located on the local system. The other data and bin files should remain on the server system. If you are not running WQ on a server, this directory should be pointing to the location of the winqk32.exe file. Common to all Windows: You can now print the Event, FFT or Event Location Map windows in color. In the File menu item you will see a new menu item called Print Settings. You can turn color printing on or off using the Color menu item. If selected, the colors used for printing will be the same ones selected for the event/fft/map windows except the background color. This can be different from the window background color to save ink. Event Window: I made a major change to how WQ displays the data in memory. Before WQ would read in the data from an event file into a 16 bit array. This is fine for the current PSN format since it only has 16 bit numbers. The problem was when WQ read in another format (SEED, PEPP, SAC etc) that had bigger numbers than +- 32000 counts, it needed to divide the data down so that it would fit into the 16 bit array. WQ now reads and displays the data in a 32 bit array. Since WQ no longer needs to divide the data as it reads it in, I removed the SEED/SAC/PEPP Control dialog box (under the Options menu) that was used to control the divide number. There still is a problem when saving one of the other formats as a PSN file do to the number size difference. What I did is add a compression / divide number in the Save dialog box. If data compression is needed, a edit box will be accessible to change / override the number WQ calculates for you. I added a DC-Offset check box to the Save dialog box. Before WQ would always apply the DC offset used for centering the seismogram around zero. You can now turn this "feature" off if needed. The Save dialog box now has a new save type option. A while back I came up with some code that converted a PSN binary event file into an ASCII text file. I added this code to WQ, so you can now save any event file as text data file. Since the data numbers are not limited to a 16 bit output array, like the PSN binary version, there is no need to divide the data. Unfortunately I have not added the code to read in this format. I moved the event file start / end time correction dialog box to the Modify dialog box. This was one of the File menu items. I fixed a problem with saving the integrated data. Before, if you integrated the data and tried to save it, WQ would always save the non-integrated array (WQ keeps two arrays, one for the normal data and other if the integration feature is used). Now if you are viewing the integrated data and open the Save dialog box, the integrated data will be saved. FFT Window. I added a few new features to the FFT window. I now display the frequency and the period (1/f) of the mouse location when its somewhere in the FFT window. You can now zoom in and display one decade of frequencies. You can use the mouse to zoom in/out by double clicking or use the menu or tool bar. You can now save the FFT window as a GIF image. Event Location Map Window: I now display the event location, if known, on the left side of the window. I made it so that you can see the distance circles update as you move the P and S markers on one of the event windows. So if you open up a map window and arrange the windows so you can see both the map and the event windows, and move the P or S marker around, you should see the distance circle move for that station. You can now save the map as an GIF image and print the map window. I think that's it... I have created two zip files and placed them on two system. One zip file, wq258b_exe.zip (~300k) only contains a new exe file. If you downloaded the earlier beta release all you need to do is download this one. The other file wq258b_full.zip (~1.2meg) contains all of the files needed to run this release. Here are the links: ftp://ftp.drnet.com/users/psn/software/wq258b_exe.zip and ftp://ftp.drnet.com/users/psn/software/wq258b_full.zip or ftp://ftp.seismicnet.com/software/wq258b_exe.zip and ftp://ftp.seismicnet.com/software/wq258b_full.zip Please let me know if you run into any problems running this release. I'm going too try and NOT add any more features so I can stabilize what I have and make a more formal release. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: New WinQuake beta release version 2.5.8 Date: Wed, 03 Feb 1999 01:18:14 -0700 (MST) Larry, Winquake has really become some outstanding software for the PC. I have a few options you could add to really confuse people, but also make it better: -Multiple component display -Particle Motion Plot (2d is easiest) -Addition and subtraction, multiplication and division of seismograms. -Rotation of data into transverse, radial components. -Multiplication of FFT data: eg. multiplying the inverse of the frequency response for a seismometer with the seismogram to amplify weak portions of the spectrum. There are a few items this would need like a definite low frequency cutoff to prevent instability... ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: New WinQuake beta release version 2.5.8 Date: Wed, 03 Feb 1999 12:15:32 -0700 Larry Cochrane wrote: > Today I released a new beta version of WinQuake. This is beta version > 2.5.8. I made a few changes from the last release so heres what's new. > > New Command Line option: > Currently WinQuake (WQ) can print a file from the command line. The format is: > winqk32 /p file_name I added the ability to create a gif image of the > event file. The format is winqk32 /g input_file [output_file_or_dir]. The I bet that's handy for the new event files section of your web site. Also someone could set up their own NT server web site with it. Legally? I have no use personally. Hey maybe someday. You never know. It is possible. In theory anyways. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: question - Scream program? Date: Wed, 03 Feb 1999 14:08:57 -0800 I got this message today from Rex Dickens. I told him that I don't know anything about this program and that I would forward his message to the PSN-L list. If you can help please email him directly. Thanks, -Larry Cochrane >From: Rex0110@....... >Date: Wed, 3 Feb 1999 15:57:55 EST >To: cochrane@.............. >Subject: question >X-Mailer: AOL 3.0 16-bit for Windows sub 86 > > Let me first say I don't know if this message will aply to you. If not >could you please tell me where to go or who to ask to get my question >answered. > > For a school research project I am researching seismic waves and >earthquakes. We are using a program called SCREAM! version 2.1 We need the >system requirements for this program. For now it is on a tempary computer, >but we will be moving it to a different one. We are connected with PSN, we >got the software from Indiana University, Bloomington, IN and don't have the >requirements. > > If you need more information either email me or the teacher incharge >John Portle (jportle@.......... >Bloomington High School North >Bloomington Indiana > Thank you for your time. >Rex Dickens > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Northern California double event Date: Wed, 03 Feb 1999 18:43:36 -0800 Hi Everyone, Today (2/03) at 16:19 PST (00:19 UTC 02/04) we had two events back to back. This is from the USGS finger service. 99/02/04 00:19:36 37.16N 121.55W 6.3 3.8Ml A* 6 mi ENE of Morgan Hill, CA 99/02/04 00:21:41 37.16N 121.55W 6.5 3.7Ml A* 6 mi ENE of Morgan Hill, CA The first event shook the computer table a little, but I did not feel it. Both events where recorded on scale with my Lehman (my SG sensor is off line). The FBA23A strong motion sensor I have also picked up both events. The first event produced a max g of around 13 mg. The second event produced ~5 mg. I have a new channel online, LC4. It is the E-W component of the FBA23A sensor. I have not been recording this channel because of a problem with the sensor. Through Edward Cranswick, Kinemetrics fixed and re calibrated the sensor. I also changed the gain the of FBA Z channel. It was set to +-1 g max (+-32768 A/D counts), it is now set to +-2 g's like the other components. I have updated my station information web page at http://www.seismicnet.com/stations.html with more information about the FBA channels. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: bzimmerman@............ Subject: Re: question - Scream program? Date: Thu, 04 Feb 1999 08:26:49 -0500 (EST) Scream is from Guralp systems. Try their Web page for more info: http://www.guralp.demon.co.uk/ Brian Zimmerman On Wed, 3 Feb 1999, Larry Cochrane wrote: > I got this message today from Rex Dickens. I told him that I don't know > anything about this program and that I would forward his message to the > PSN-L list. If you can help please email him directly. > > Thanks, > > -Larry Cochrane > > >From: Rex0110@....... > >Date: Wed, 3 Feb 1999 15:57:55 EST > >To: cochrane@.............. > >Subject: question > >X-Mailer: AOL 3.0 16-bit for Windows sub 86 > > > > Let me first say I don't know if this message will aply to you. If not > >could you please tell me where to go or who to ask to get my question > >answered. > > > > For a school research project I am researching seismic waves and > >earthquakes. We are using a program called SCREAM! version 2.1 We need the > >system requirements for this program. For now it is on a tempary computer, > >but we will be moving it to a different one. We are connected with PSN, we > >got the software from Indiana University, Bloomington, IN and don't have the > >requirements. > > > > If you need more information either email me or the teacher incharge > >John Portle (jportle@.......... > >Bloomington High School North > >Bloomington Indiana > > Thank you for your time. > >Rex Dickens > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: question - Scream program? Date: Thu, 04 Feb 1999 10:21:41 -0700 John- Steve Horton, Debi Kilb and Paul Bodin very effectively used the SCREAM system during our recent study of the 1998 Sep 25 Pymatuning Earthquake in Pennsylvania/Ohio. Their results from SCREAM are described on the at this website: -Edward Larry Cochrane wrote: > I got this message today from Rex Dickens. I told him that I don't know > anything about this program and that I would forward his message to the > PSN-L list. If you can help please email him directly. > > Thanks, > > -Larry Cochrane > > >From: Rex0110@....... > >Date: Wed, 3 Feb 1999 15:57:55 EST > >To: cochrane@.............. > >Subject: question > >X-Mailer: AOL 3.0 16-bit for Windows sub 86 > > > > Let me first say I don't know if this message will aply to you. If not > >could you please tell me where to go or who to ask to get my question > >answered. > > > > For a school research project I am researching seismic waves and > >earthquakes. We are using a program called SCREAM! version 2.1 We need the > >system requirements for this program. For now it is on a tempary computer, > >but we will be moving it to a different one. We are connected with PSN, we > >got the software from Indiana University, Bloomington, IN and don't have the > >requirements. > > > > If you need more information either email me or the teacher incharge > >John Portle (jportle@.......... > >Bloomington High School North > >Bloomington Indiana > > Thank you for your time. > >Rex Dickens > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Taber Subject: Re: scream software Date: Fri, 5 Feb 1999 09:43:08 +1300 (NZDT) I've sent the following by email but I thought some people on the PSN list might be curious so I've copied my answer to the list. Rex, Larry Cochrane put your question about scream on the PSN mailing list. I'm guessing that the scream v2.1 program you refer to is one written by Guralp Systems (they make some of the PEPP seismographs). The information pages for the software can be found at http://www.guralp.demon.co.uk/software/scream/index.htm. From my limited understanding of the program (we tried out an earlier version) it is primarily a data aquisition program. Will you be using it to collect data from a seismometer or for analysing data collected elsewhere? Regards, John Taber John Taber School of Earth Sciences, Victoria University John.Taber@.............. Box, 600, Wellington, New Zealand phone: +64-4-472-1000 fax: +64-4-495-5186 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: PSN newspaper story Date: Thu, 04 Feb 1999 14:20:16 -0700 Kathleen- I just got the photocopy you sent me of your newspaper article for the Santa Cruz (CA) Sentinel (Saturday, 30 Jan, p. A2) about the Public Seismic Network (PSN) and Mark Halliday in Ben Lomond, CA, and I think the article is excellent! Perhaps, it could be scanned (I don't know what the copyright rules are), and Larry Cochrane could put it in area for newspaper articles, etc., on the RWC/PSN . -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: [Fwd: Morgan Hill doublet recorded from Ben Lomond] Date: Thu, 04 Feb 1999 14:42:32 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". Mark- You recorded very nice records of the Morgan Hill doublet (990204a.mh1 & .mh2), except that the peak values of the first event exceeded your 12-bit A/D by about 50% full-scale. Up in the mountains, you have a wonderfully quiet recording site compared to those poor guys down in the mud and freeways of Silicon Valley. That's why the USGS put all the Calnet stations up in the hills, because nobody lives there and it's so quiet ... unfortunately it is in Silicon Valley where everyone lives that we also need to have recordings of earthquakes so we will know what effects, i.e., damage, may happen next time there is a large event. But I'd rather live in Ben Lomond, and it is good place to study seismic sources. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Larry Cochrane Subject: Re: New WinQuake beta release version 2.5.8 Date: Thu, 04 Feb 1999 17:10:07 -0800 At 01:18 AM 2/3/99 -0700, John Hernlund wrote: >Larry, > Winquake has really become some outstanding software for the PC. I have a >few options you could add to really confuse people, but also make it better: Thanks John. > >-Multiple component display Edward C. has also asked for this one. >-Particle Motion Plot (2d is easiest) >-Addition and subtraction, multiplication and division of seismograms. >-Rotation of data into transverse, radial components. >-Multiplication of FFT data: eg. multiplying the inverse of the frequency > response for a seismometer with the seismogram to amplify weak portions of > the spectrum. There are a few items this would need like a definite low > frequency cutoff to prevent instability... As I learn how to do these things, I'll add them... -Larry Cochrane _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: New WinQuake beta release version 2.5.8 Date: Thu, 04 Feb 1999 18:40:07 -0700 (MST) On Thu, 4 Feb 1999, Larry Cochrane wrote: > >-Particle Motion Plot (2d is easiest) Parametric plot from two files. It would just be a plot of the amplitude component from one channel vs. the amplitude data from another with both sharing the same time values. Of course different sampling rates would be a problem, but the faster channel could be re-sampled to the slower one... > >-Addition and subtraction, multiplication and division of seismograms. This might take a lot of memory. Perhaps the program could open two files and add the corresponding values one at a time (I do this with fortran usually) and then write the result to a new file. > >-Rotation of data into transverse, radial components. This is not too hard, it just sounds worse than it is. It is possible to rotate the data about any of three perpendicular axes using three very simple matrices for any angle. This is equivalent to finding the component of one channel onto a different coordinate system offset by definite angles... > >-Multiplication of FFT data: eg. multiplying the inverse of the frequency > > response for a seismometer with the seismogram to amplify weak portions of > > the spectrum. There are a few items this would need like a definite low > > frequency cutoff to prevent instability... This is more of an experimental thing. If the user records an input pulse to his/her seismograph and stores the FFT of this file, then the deconvolution of an earthquake file would consist in dividing the FFT for the event by the FFT for the impulse of the seismometer. Frequencies from the event below a certain level would have to be cut off (bandpassed) because some times trying to add information into a time series that was never there in the first place adds instability (weird results). > As I learn how to do these things, I'll add them... If there is any information or anything else I could do to help just let me know... ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Dennis W. Pope" Subject: Advice/Recommendations Date: Fri, 5 Feb 1999 07:02:06 -0500 I am looking for advice and recommendations as to what type of seismomete= r (vertical, horizontal, GS, Lehman, etc) I should install for amateur use = in my home. I would be like to keep the cost in the $2000 to $3000 range. I = am located in central Ohio. I want to acquire the data on a PC which I have and can dedicate for this use. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: Re: Advice/Recommendations Date: Sat, 6 Feb 1999 12:53:07 -0600 (CST) Dennis, The most interesting earthquake data comes from a broadband vertical sensor. The energy comming from an earthquake has strong components of the body (or direct) waves (P and S) that generally are of periods of one second or so, and the later surface waves can range from 20 to hundreds of seconds. So at St. Louis U, we have broadband pen-and ink monitor recorders (the classical helical drum format) of our more sensitive stations to allow us to keep up with global activity in real time; most of the actual data disappears into the computers for later analysis. The homemade sensors you ask about (Lehman, SG) are very primitive (my opinion) designs that don't even encompass modern concepts of seismometer design. They are also horizontal sensors so they respond poorly to the primary waves of distant (1000 km or more) earthquakes. Several members of the PSN have had success building the broadband vertical seismometer that I describe at: http://www.eas.slu.edu/People/STMorrissey/ stmseis.html" The STM-8 Leaf Spring Seismometer: Photos and Report stmfigs.html" The STM-8 Seis: Figures, Schematics, Drawings stmquakes.html" The STM-8 Seis: Recent Quakes, Data A major advantage of this design is that the instrument response, including the damping, is mostly controlled by electronic components of the feedback system, so the response is linear and calibrated over a wide range regardless of variations on the the mechanical behavior of the sensor such as the mechanical period. A significant advantage of a very broadband response is that when most of the earthquake energy is within the "flat" portion of the velocity response, the shape of the response does not have to be considered in analyzing the data. Like for a teleseism with 1hz P waves and 20 to 60 second surface waves, a VBB response that is flat from 30hz to 120 seconds will accurately record all the ground motion. THis can be seen in some of the data samples where comparison is made to regional broadband stations, (which have commercial VBB sensors that are flat from 20hz to 360 seconds) and the waveform differences are mostly because of different ray paths to the stations from the earthquake source in south America. The mechanics of the assembly of the hardware-store seismometer are pretty straight forward, and the electronics can be assembled on a perforated type circuit board if you can read a schematic and do soldering. I am hoping to get a local company to prefab the electronics into a "plug and play" box that hopefully won't cost more than $100. I am currently recycling circuits from other projects for the prototypes I have built, so the circuits appear more complex than necessary. I have recently re-worked the 4-amplifier card to include the integrator, so the instrumentation-style amplifier is not needed. I haven't scanned and posted the revision...... yet. We have had a wide assortment of discussions of the construction details on the PSN. However, I don't think they have been organized in any sense. I am working with a local instrumentation company try to produce a complete version of the hardware-store seismometer. It will be hopefully be available next fall and cost $800 or more. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: MAJ QUAKE !!!!!!!!!!1 NOWWWW Date: Sun, 7 Feb 1999 10:57:10 +1300 MAJOR QUAKE in progress 2156 UT 06 feb Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: MAJ QUAKE !!!!!!!!!!1 NOWWWW Date: Sat, 06 Feb 1999 14:07:32 -0800 I love it when email about a new event arrives before the P wave. P wave hit here around 22:02:00 UTC -Larry At 10:57 AM 2/7/99 +1300, you wrote: > MAJOR QUAKE in progress 2156 UT 06 feb > > >Dave >Co-ordinator: >New Zealand >Public Seismic Network > Dave A. Nelson ZL4TBN > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > >http://www.seismicnet.com/dave/home.htm > >IF there indeed are other parallel universes... I can now rest in the >knowledge, that in at least one of them, I am filthy rich and drive a red >Ferrari > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Liberio Rossi" Subject: Quake in progress!!!!!!! Date: Sat, 6 Feb 1999 23:51:02 +0100 Here recorded P wave 22.06.00 lat.43.54.79n long.1031.56 From: "." Subject: R: MAJ QUAKE !!!!!!!!!!1 NOWWWW Date: Sun, 7 Feb 1999 00:01:48 +0100 SIRACUSA (Sicily) Pkp wave hit here around 22:07 UTC Claudio Conti CONTI CLAUDIO conticl@........... -----Messaggio originale----- Da: Larry Cochrane [SMTP:cochrane@............... Inviato: sabato 6 febbraio 1999 23.08 A: PSN-L Mailing List Oggetto: Re: MAJ QUAKE !!!!!!!!!!1 NOWWWW I love it when email about a new event arrives before the P wave. P wave hit here around 22:02:00 UTC -Larry At 10:57 AM 2/7/99 +1300, you wrote: > MAJOR QUAKE in progress 2156 UT 06 feb > > >Dave >Co-ordinator: >New Zealand >Public Seismic Network > Dave A. Nelson ZL4TBN > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > >http://www.seismicnet.com/dave/home.htm > >IF there indeed are other parallel universes... I can now rest in the >knowledge, that in at least one of them, I am filthy rich and drive a red >Ferrari > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: NO ATTACHMENTS PLEASE and station ID's Date: Sat, 06 Feb 1999 15:23:05 -0800 Everyone, This is a not so gentle reminder that attachments should NOT be sent to this list. If you have an event file, please send it the archive system at event@............... This way it will get placed on my FTP / Web server system so others can download it. All other files should be posted on a web site somewhere and the URL sent out on the list. And while I'm at it... If you are running a PSN station and send in event files, please us a unique station / sensor ID. Please don't use the default SDR channel names (event file extension) of *.CH1, *.CH2 etc. Thanks, -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Advice/Recommendations Date: Sat, 06 Feb 1999 16:45:09 -0700 Sean- However they are relatively easy to understand and construct working models of, and their data has been routinely posted to the PSN since the first BBS in 1991. -Edward S-T Morrissey wrote: > The homemade sensors you ask about (Lehman, SG) are very primitive (my opinion) > designs that don't even encompass modern concepts of seismometer design. > They are also horizontal sensors so they respond poorly to the primary > waves of distant (1000 km or more) earthquakes. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: Re: Advice/Recommendations Date: Sat, 6 Feb 1999 18:24:51 -0600 (CST) Edward, I fully agree with what you say about the Lehman and SG designs. They do work, and those who have made them and continue to operate them should be commended. I am only trying the raise the bar; I believe that we can do better. Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: Mb 7.3, Santa Cruse Isl. Date: Sat, 6 Feb 1999 18:27:57 -0600 (CST) The following near-real-time Earthquake Bulletin is provided by the National Earthquake Information Service (NEIS) of the U. S. Geological Survey as part of a cooperative project of the Council of the National Seismic System. For a description of the earthquake parameters listed below, the availability of additional information, and our publication criteria, please finger qk_info@.................. 99/02/06 21:47:59 12.96S 166.67E 90.2 7.3Ms B SANTA CRUZ ISLANDS _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Rough Draft of Seismograph Theory Page Date: Sat, 06 Feb 1999 17:59:25 -0700 John- I liked the graphics but not the equations: one of the reasons I stayed in field seismology was to stay away from the black boards ... but that's my prejudice. -Edward John Hernlund wrote: > Hello Everyone, > Because of many requests for information and general questions about > seismographs from people on the internet and in my community I have decided to > undertake a project that describes the way seismometers work both > mathematically and graphically. This is because I can never find a good book > to refer people to that ties all the concepts together. I have only covered > material pertaining to simple damped seismometers, but I plan to add more > material as I go eventually describing some of the mathematics of various > filters, the sampling process, Fourier Analysis, and other usually advanced > and scattered topics. > > It is only a rough draft now, but I thought the PSN would be the perfect > place to ask for a review and suggestions on what has been completed thus far. > If you get the chance, read through it, and e-mail me any > comments/suggestions that you have. Be honest: if it sucks and doesn't make > any sense at all, then let me know because you won't be the first to feel that > way! > > ****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > http://www.public.asu.edu/~hernlund/ > > ****************************************************************************** > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: George Bush Subject: Mystery quake close to Sea Ranch, CA, USA Date: Sat, 06 Feb 1999 17:04:05 -0800 Hello: I detected a sharp earthquake 02-05-99 at 19:16 PT (time approximate to + or - 5 min.) that had a 4.4 second difference between easily-seen P and S waves for a distance from here of 4mi.! I was not abe to find anything listed on the USGS site of recent earthquakes? If you have any other sources I would be interested in knowing if anyone else has seen it and where this quake was located. You can go to http://psn.quake.net/cgi-dos/event.exe and see it. Look for the event file with the .tsr extension. George Bush Sea Ranch, CA, USA 38.74N, 123.5W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: New WinQuake beta release Date: Sat, 06 Feb 1999 20:12:23 -0700 Larry & Arie- I have fallen behind in keeping up with what you guys have been doing with the new WinQuake and Autodrm but ... IT IS SIMPLY MIND-BOGGLING!!!! -Edward Larry Cochrane wrote: > Hi Everyone, > > Happy New Year. In the last few months I have been working on a new > Winquake (WQ) release. With some help from Arie Verveer (thanks Arie!) I > think I have a stable beta release ready.I sent Arie a pre-beta release so > he could checkout one of the new features in this release. I used the code > he wrote to convert GSE2.0 files to the PSN format to allow WQ to view > event files in that format. He ended up finding a few major bugs that where > not happening on my system. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Angel Rodriguez Subject: Re: Advice/Recommendations Date: Sun, 7 Feb 1999 17:27:34 -0500 At 07:02 AM 02/05/1999 -0500, you wrote: >I am looking for advice and recommendations as to what type of seismometer >(vertical, horizontal, GS, Lehman, etc) I should install for amateur use in >my home. I would be like to keep the cost in the $2000 to $3000 range. I am >located in central Ohio. I want to acquire the data on a PC which I have >and can dedicate for this use. Hi, There is a company in Switerland that sella complete 3 axis package with GPS time refernce for less that 3000.00. It comes complete with data logging software and Seisan for looking at =F1the data. The call it the GBV-316 Seismic Recorder and it has 4.5 hz geophones inside, 2 meg of memory, ring buffers, self diagnostics, and will connect to your PC thru the serial port or thru a modem. Transfer factor 28 Vs/m gain of 10, 100, 1000 jumper selectable 16 bit AtoD Their email is geosys@.......... You can also get most of the electronics from Larry and build your own devices, which is half the fun anyway. Hope it helps, A. Rodriguez _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Speaker magnet Date: Sun, 07 Feb 1999 18:18:51 -0800 Hi All For increasing the gap of a speaker magnet it is necessary to file, machine or whatever the metal plates. As a note, I soaked the magnet in carburetor cleaner for a week or so and it dissolved the adhesive between the magnet and the plates. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: robert barns <75612.2635@..............> Subject: Re: Advice/Recommendations Date: Mon, 8 Feb 1999 12:02:00 -0500 The Swiss device has 4.5 Hz geophones which would work ONLY with local events. This would be no good for seeing events worldwide. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: TMichel917@....... Subject: Re: Advice/Recommendations Date: Mon, 8 Feb 1999 12:22:39 EST The GBV-316 is also available as digitizer only. You can connect other sensors than the internal SM-6 4,5 Hz geophone to this digitizer. Detailed information is available at: http://www.geosys.ch Torsten Michel _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: File transfering Date: Tue, 09 Feb 1999 22:07:57 -0800 I was reading the latest issue of Sensors magazine and I was reminded of a question I ment to ask a while back. I was wondering how easy it would be to connect a cellular phone at a remote seismic site to a base station computer. I wouldn't mind the daily cost of a local phone call it I could receive the days data from a remote station. The plan would be to dial the cell phone number from my house modem. This call would interupt the EMON , SDR or other DOS acquisiton program. I would download the days data, clear the memory and hang up. I would need modems at both ends but is the software out there? Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: File transfering Date: Tue, 09 Feb 1999 23:14:57 -0700 Barry- We have been messing around with this at USGS for a couple of years now, and it has been a real pain. We ran a remote site in Seattle by cell-phone for several months, and we are about to put in several other sites. I will CC this reply to Mark Meremote who is the working on this system. -Edward barry lotz wrote: > I was reading the latest issue of Sensors magazine and I was > reminded of a question I ment to ask a while back. I was wondering how > easy it would be to connect a cellular phone at a remote seismic site to > a base station computer. I wouldn't mind the daily cost of a local phone > call it I could receive the days data from a remote station. The plan > would be to dial the cell phone number from my house modem. This call > would interupt the EMON , SDR or other DOS acquisiton program. I would > download the days data, clear the memory and hang up. I would need > modems at both ends but is the software out there? > Regards > Barry > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: File transfering Date: Tue, 09 Feb 1999 23:16:00 -0700 PS. What kind of sensors are you now recording? barry lotz wrote: > I was reading the latest issue of Sensors magazine and I was > reminded of a question I ment to ask a while back. I was wondering how > easy it would be to connect a cellular phone at a remote seismic site to > a base station computer. I wouldn't mind the daily cost of a local phone > call it I could receive the days data from a remote station. The plan > would be to dial the cell phone number from my house modem. This call > would interupt the EMON , SDR or other DOS acquisiton program. I would > download the days data, clear the memory and hang up. I would need > modems at both ends but is the software out there? > Regards > Barry > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: Winquake problem Date: Tue, 09 Feb 1999 22:22:57 -0800 At 12:54 PM 2/8/99 -0400, you wrote: >Hello Larry > >I just noticed a problem with the new release of Winquake which I >thought I would bring to your attention. Whenever I save as a GIF image, >I cannot close the event file and open another. The system tells me that >it cannot find the files. > >Wayne Wayne, I can't duplicate this problem. I'm CCing the PSN-L list to see if anyone else has seen this problem. Does this problem happen only on the event window, or does it happen when you save a FFT or map window as a gif image? -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Karl Cunningham Subject: Re: File transfering Date: Wed, 10 Feb 1999 09:27:31 -0800 Barry -- I don't have any direct experience with this, but the California Department of Transportation is using a cellular-phone based system to download data from solar-powered weather stations along remote highways. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... At 10:07 PM 2/9/99 -0800, you wrote: > I was reading the latest issue of Sensors magazine and I was >reminded of a question I ment to ask a while back. I was wondering how >easy it would be to connect a cellular phone at a remote seismic site to >a base station computer. I wouldn't mind the daily cost of a local phone >call it I could receive the days data from a remote station. The plan >would be to dial the cell phone number from my house modem. This call >would interupt the EMON , SDR or other DOS acquisiton program. I would >download the days data, clear the memory and hang up. I would need >modems at both ends but is the software out there? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "James M Hannon" Subject: Re: File transfering Date: Wed, 10 Feb 1999 15:51:42 -0600 A friend of mine at work did something like this for a transmitter locating experiment using remote receivers. He used a program called Doorway which basically lets you log onto the remote PC via the dial up phone connection. Unfortunately I cannot find any other information on Doorway. But another program called PCanywhere will also do the same job http://www.symantec.com/pcanywhere/fs_pcawin20.html. The programs are both dos based. I am not 100% sure but I think that with PCanywhere you wouldn't even have to interrupt the operation of the EMON or SDR to log in and download your data files. Jim Hannon barry lotz on 02/10/99 12:07:57 AM Please respond to PSN-L Mailing List To: psn list cc: Subject: File transfering I was reading the latest issue of Sensors magazine and I was reminded of a question I ment to ask a while back. I was wondering how easy it would be to connect a cellular phone at a remote seismic site to a base station computer. I wouldn't mind the daily cost of a local phone call it I could receive the days data from a remote station. The plan would be to dial the cell phone number from my house modem. This call would interupt the EMON , SDR or other DOS acquisiton program. I would download the days data, clear the memory and hang up. I would need modems at both ends but is the software out there? Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Francesco Subject: Re: File transfering Date: Wed, 10 Feb 1999 23:16:44 +0100 Hi guy. In our network, we courrently use PcAnywhere (freeware) to download, via modem pc to pc, the files of the remote stations. No conflict or interruption with Sdr in progress or with other programs. PcAnywhere runs under Dos too. Another system that I use is the Microsft Plus extension, wich is able to connect two or many remote pc via modem (this is an utility of the "remote access"), with the file's condivision. But it require W95 platform (I take run Sdr under Win95 - Dos application - in a Pentium 350 without problems). Win98 don't require MSoft Plus bucause include this option. Regards Francesco Nucera I.E.S.N. - PSN Italy _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: ralvarez@........ (Raul Alvarez) Subject: Re: File transfering Date: Wed, 10 Feb 1999 18:17:46 -0700 (MST) Hello, Do you know if PCAnywhere is available on the internet? Raul >Hi guy. >In our network, we courrently use PcAnywhere (freeware) to download, via >modem pc to pc, the files of the remote stations. >No conflict or interruption with Sdr in progress or with other >programs. >PcAnywhere runs under Dos too. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "My dreams are the seeds of my reality, nurtured in the womb of my soul" RJA, 1985 Raul J. Alvarez La Estrellita Observatory Bellvue, Colorado e-mail ralvarez@........ homepage www.frii.com/~ralvarez "The Renaissance Experimenter" doing research in: Radio and Optical Astronomy, Seismology, Weather, Computers, Instrumentation and Neat Stuff! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Interesting article on sensors. Date: Wed, 10 Feb 1999 18:14:44 -0800 Hi Everyone, Interesting article on sensor at http://www.sensorsmag.com/toc_0299.htm. Select the "A practical Approach to Vibration..." link. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Francesco Subject: Re: File transfering Date: Thu, 11 Feb 1999 08:42:52 +0100 Try at http//www.symantec.com But PcAn is a very large programm. the latest version is more than 4 mb You should find it in some commercial cd internet newspaper... Francesco Nucera I.E.S.N. PSN Italy _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: File transfering Date: Thu, 11 Feb 1999 19:20:28 -0800 Edward I currently have one ~30 sec Lehman, two homemade STM verticals(24"&12") and one geophone(Gateway electronics $10 special). I'm currently constructing a horizontal like STM posted on his web site. I was hopeing to incorporate the "triple" feedback with it. They are all connected to my house via shielded cables. I would like to install one in a remote location (mine shaft or up on the Sierra Nevada mtns). Crank the gain up. Regards Barry Edward Cranswick wrote: > PS. What kind of sensors are you now recording? > > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: File Transfering Date: Thu, 11 Feb 1999 19:34:23 -0800 Thanks all! I'll try to upload and work with pcanywhere. I think experiment by putting a 286 computer in my garage with the sensors and try to connect it with the house. Sensors magazine said they had better luck with low speed modems (1200 baud).We'll see if I can get it to work with Emon and an extra Acqutek 12 bit board. Thanks again for the response. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: File transfering Date: Thu, 11 Feb 1999 19:57:04 -0800 Francesco I'm not cheap ---but I only found the $150 version on the internet. Barry Francesco wrote: > Hi guy. > In our network, we courrently use PcAnywhere (freeware) to download, via > modem pc to pc, the files of the remote stations. > No conflict or interruption with Sdr in progress or with other > programs. > PcAnywhere runs under Dos too. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: File transfering Date: Thu, 11 Feb 1999 20:13:30 -0800 PC Anywhere is not freeware. They have a demo version that runs of 30 or 45 days available on there web site, but it is only for Win95/98/NT. The DOS / Win 3.1 version is not available for download. On their web site the cost was $179.00 for the DOS / Win 3.1 version. I use the 32 bit version of PC Anywhere almost every day for remotely maintain several NT systems on the Internet. Its a great program! Even when I had the 28K connection to the net, it was very useful. Now that I have the DSL line it's almost like being at the remote computer. Francesco, it is very good news that the DOS version (I have never used the DOS / Win 3.1 version) runs with EMON and SDR. Thanks for the information. -Larry Cochrane Redwood City, PSN At 07:57 PM 2/11/99 -0800, you wrote: >Francesco > I'm not cheap ---but I only found the $150 version on the internet. > Barry > > >Francesco wrote: > >> Hi guy. >> In our network, we courrently use PcAnywhere (freeware) to download, via >> modem pc to pc, the files of the remote stations. >> No conflict or interruption with Sdr in progress or with other >> programs. >> PcAnywhere runs under Dos too. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Fwd: origin of name of Lehman(n) sensor Date: Thu, 11 Feb 1999 23:03:29 -0800 FYI, Ken and I received this today.... -Larry >Date: Thu, 11 Feb 1999 22:54:55 -0800 >From: Ed Thelen >Reply-To: ethelen@........ >Organization: @Home Network >X-Mailer: Mozilla 4.05 [en]C-AtHome0402 (Win95; I) >To: kjn@.......... >CC: cochrane@.............. >Subject: origin of name of Lehman(n) sensor > >While reading > http://www.seismicnet.com/info/homefaq.txt > >I saw question >" >Aside: > No one seems to know if the Lehman(n) sensor is named after the >author, > James D. Lehman, or the famed Danish seismologist, Inge Lehmann, >who > published a paper in 1936, that postulated that the earth held >an inner > core estimated to be about the size of our moon within the outer >core. > If someone has some information on this please forward it to me > so I can include it in the next update of the FAQ. >(kjn@........... >" > >I was editor of WASS (World Amateur Seismological Society) - RIP - >in the early 1970s. > 1) long period instruments - say from Springneither (sp) > or of amateur construction were informally called > "garden gate" or "Galtzin" (sp) style > 2) I never heard of a "Lehman" style - >so assume that the Lehman style is due to James D. > >-------------------- > >I cannot comprehend why someone would construct >such a weak, complex double vertical post >"Lehman" design using 3/4 inch tubing. > - poor rigidity > - ridiculous to analyze for vibrations > - low frequency natural resonance > >The several instruments I constructed were of >2 inch copper tubing and had a single >vertical post - sturdy, quite rigid, >high natural resonance frequency. > >Cheers > Ed Thelen > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Francesco Subject: Re: File transfering Date: Fri, 12 Feb 1999 08:42:11 +0100 Barry, If you decide to use PcAn and if you don't find it in another way, if you want I can send you the floppy. Francesco _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Steve Hammond Subject: Re: File transfering Date: Fri, 12 Feb 1999 23:15:51 -0800 Hi Barry, Larry, Ed, and Others, I was reading the MEIAL string and wanted to add a few comments about some EMON features Ted had been working on and a comment or two about PCAnywhere. Ted started working on a version of EMON that could be setup to page a pager, drop to DOS run a Bat file, and clean up files based on time, day or event. During testing it hung a few times, and at the PSN meeting Ted said he would look at it and make repairs when he had time. Don't know where that stands today. Guess I better drop Ted a line... It was very cool when it worked. PCAnywhere In 1991, my brother and loaded PCAnywhere on a PC2 running SDAS. It worked as adverstised and displayed/accepted input in realtime from the remote console / keyboard. 1200 BAUD was a bit too slow. However, I was able to transfer data from the remote site on demand. Regards, Steve Hammond PSN San Jose, California barry lotz wrote: > > I was reading the latest issue of Sensors magazine and I was > reminded of a question I ment to ask a while back. I was wondering how > easy it would be to connect a cellular phone at a remote seismic site to > a base station computer. I wouldn't mind the daily cost of a local phone > call it I could receive the days data from a remote station. The plan _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: File transfering Date: Fri, 12 Feb 1999 20:11:30 -0800 Hi Everyone I went by Compusa today and Pcanywhere comes with a DOS and windows version included. Not to belabor the string but the next step for me is tying it to a cell phone. The store says that the modem used has to be "cellular compatable". It seems that the new modems would be more likely to be "cell compatable"(what ever that means) but new modems may be less likely to run under DOS. It seems to me that a remote site should be bare bones ie. low power and memory saved for event files and not operating system. Can one get DOS, low power modems that can work with analog cell phones? I would use a passive backplane system with processor card. Regards Barry ps. I have a Motorola analog flip phone I would like to use. I assume the modem line and the power all come into the phone bottom. (12 volt battery and modem line) > Hi Barry, Larry, Ed, and Others, > I was reading the MEIAL string and wanted to add a few comments about > some EMON features Ted had been working on and a comment or two about > PCAnywhere. Ted started working on a version of EMON that could be setup > to page a pager, drop to DOS run a Bat file, and clean up files based on > time, day or event. During testing it hung a few times, and at the PSN > meeting Ted said he would look at it and make repairs when he had time. > Don't know where that stands today. Guess I better drop Ted a line... It > was very cool when it worked. > > PCAnywhere > In 1991, my brother and loaded PCAnywhere on a PC2 running SDAS. It > worked as adverstised and displayed/accepted input in realtime from the > remote console / keyboard. 1200 BAUD was a bit too slow. However, I was > able to transfer data from the remote site on demand. > > Regards, Steve Hammond > PSN San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Rudolph Norvelle" Subject: Setting up a seismograph Date: Fri, 12 Feb 1999 21:02:21 -0800 Hello, I am in the midst of trying to set up a Lehman seismograph. = However before I get started I want to determine the best spot in my = house to set it up. Does anyone have experience with setting upn their = seismograph in there garage. would the foot traffic be a problem? = Fortunatly my house is on a cul-de-sac so there is not a whole lot of = automobile traffic, but there are a lot of kids running around. Would = it be more practical if I tried to place the sensor under my house in an = insulated case, etc? Any help would be appreciated. Thanks in advance. Rudy Norvelle
    Hello,
        I am in the = midst of=20 trying to set up a Lehman seismograph.  However before I get = started I want=20 to determine the best spot in my house to set it up.  Does anyone = have=20 experience with setting upn their seismograph in there garage. would the = foot=20 traffic be a problem?   Fortunatly my house is on a cul-de-sac = so=20 there is not a whole lot of automobile traffic, but there are a lot of = kids=20 running around.  Would it be more practical if I tried to place the = sensor=20 under my house in an insulated case, etc?  Any help would be=20 appreciated.
 
         &nb= sp;           &nbs= p;            = ; =20 Thanks in advance.
         &nb= sp;           &nbs= p;            = ;   =20 Rudy Norvelle
From: Ken Navarre Subject: Re: origin of name of Lehman(n) sensor Date: Fri, 12 Feb 1999 21:25:14 -0800 (PST) On Thu, 11 Feb 1999, Ed Thelen wrote: > While reading > http://www.seismicnet.com/info/homefaq.txt > > I saw question " Aside: > No one seems to know if the Lehman(n) sensor is named after the > author, James D. Lehman, or the famed Danish seismologist, Inge Lehmann, > who published a paper in 1936, that postulated that the earth held > an inner core estimated to be about the size of our moon within the outer > core. > If someone has some information on this please forward it to me > so I can include it in the next update of the FAQ. > (kjn@........... > I was editor of WASS (World Amateur Seismological Society) - RIP - > in the early 1970s. > 1) long period instruments - say from Springneither (sp) > or of amateur construction were informally called > "garden gate" or "Galtzin" (sp) style > 2) I never heard of a "Lehman" style - > so assume that the Lehman style is due to James D. Hi Ed, your assumption is quite correct. As a matter of fact A year or so ago I got an e-mail from James D. Lehman. He was quite suprized that his sensor had become so popular. He also confirmed that he and Inge were not related although he also confirmed that he would have certainly been proud to have her in his family tree! (as would most of us...) Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Frank Cooper" Subject: Re: Setting up a seismograph Date: Sat, 13 Feb 1999 00:31:00 -0600 HI Rudy, Following is my personal experience. My Lehman is set up near my double = garage overhanging door (the car entrance which I do not use). I can = use approx. 1/2 the garage on the side opposite the seismograph. On the = side opposite the garage overhanging car door are located the person = entrance door, a washing machine, a drier, a table saw, and the = seismograph computer read-outs and chart recorder, all of which I use = without significant inteference with the Lehman. However, I cannot go = into the half of the garage with the Lehman without throwing the chart = recorder and electronic reading off scale. I tell my grand daughters = the half of the garage with the seismograph is off-limits. I draw a = line which I tell them not to cross. Nor do I cross it unless I turn = off the amps first. I live on a heavily travelled street about 40 feet = from the garage car entrance and the seismograph. I "see" every vehicle = that goes by on the CRT but fortunately Larry Cochrane's software = filters out most of this inteference. If I stand immediately outside = the car entrance overhead doors the seismograph read-outs are thrown off = scale. I park my cars on the driveway and walk behind my cars when I = walk past the garage. I don't walk immediately in front of the garage = door. One morning about three am as I was studying the computer CRT and = chart recorder I realized that someone was standing just outside my = garage door and in front of my astrovan. Fortunately he ran when I went = out the person door.=20 Eventually I plan to locate two seismic instruments behind the house in = a low roll-off shed with concrete foundation. Hope this helps. Frank Cooper, Friendswood, Texas, USA -----Original Message----- From: Rudolph Norvelle To: PSN-L@.............. Date: Friday, February 12, 1999 11:08 PM Subject: Setting up a seismograph =20 =20 Hello, I am in the midst of trying to set up a Lehman seismograph. = However before I get started I want to determine the best spot in my = house to set it up. Does anyone have experience with setting upn their = seismograph in there garage. would the foot traffic be a problem? = Fortunatly my house is on a cul-de-sac so there is not a whole lot of = automobile traffic, but there are a lot of kids running around. Would = it be more practical if I tried to place the sensor under my house in an = insulated case, etc? Any help would be appreciated. =20 Thanks in advance. Rudy Norvelle
HI Rudy,
Following is my personal experience.  My Lehman = is set up=20 near my double garage overhanging door (the car entrance which I do not=20 use).  I can use approx. 1/2 the garage on the side opposite the=20 seismograph.  On the side opposite the garage overhanging car door = are=20 located the person entrance door, a washing machine, a drier, a table = saw, and=20 the seismograph computer read-outs and chart recorder, all of which I = use =20 without significant inteference with the Lehman.  However, I cannot = go into=20 the half of the garage with the Lehman without throwing the chart = recorder and=20 electronic reading off scale.  I tell my grand daughters the half = of the=20 garage with the seismograph is off-limits.  I draw a line which I = tell them=20 not to cross.  Nor do I cross it unless I turn off the amps = first.  I=20 live on a heavily travelled street about 40 feet from the garage car = entrance=20 and the seismograph. I "see" every vehicle that goes by on the = CRT but=20 fortunately Larry Cochrane's software filters out most of this=20 inteference.  If I stand immediately outside the car entrance = overhead=20 doors the seismograph read-outs are thrown off scale.  I park my = cars on=20 the driveway and walk behind my cars when I walk past the garage. I = don't walk=20 immediately in front of the garage door.  One morning about three = am as I=20 was studying the computer CRT and chart recorder I realized that someone = was=20 standing just outside my garage door and in front of my astrovan. =20 Fortunately he ran when I went out the person door.
 
Eventually I plan to locate two seismic instruments = behind the=20 house in a low roll-off shed with concrete foundation.
Hope this helps.
Frank Cooper, Friendswood, Texas, USA
-----Original = Message-----
From:=20 Rudolph Norvelle <Rudy43Norvelle@........... tt.net>
To:=20 PSN-L@.............. = <PSN-L@..............>
D= ate:=20 Friday, February 12, 1999 11:08 PM
Subject: Setting up = a=20 seismograph

    Hello,
        I am in = the midst=20 of trying to set up a Lehman seismograph.  However before I get = started=20 I want to determine the best spot in my house to set it up.  = Does=20 anyone have experience with setting upn their seismograph in there = garage.=20 would the foot traffic be a problem?   Fortunatly my house = is on a=20 cul-de-sac so there is not a whole lot of automobile traffic, but = there are=20 a lot of kids running around.  Would it be more practical if I = tried to=20 place the sensor under my house in an insulated case, etc?  Any = help=20 would be appreciated.
 
         &nb= sp;           &nbs= p;            = ; =20 Thanks in advance.
         &nb= sp;           &nbs= p;            = ;   =20 Rudy Norvelle
From: Karl Cunningham Subject: Re: Setting up a seismograph Date: Sat, 13 Feb 1999 01:18:25 -0800 Hi Rudy -- I have a force-balance Lehman-style seismometer on the floor of my garage. Lehman-type seismometers are quite sensitive to tilting of the seismometer base. Mine works just fine, but does see footsteps anywhere in the garage or immediately outside. The major problem is not the relatively high frequency footsteps, but tilt of the garage slab when walking within about 8 feet of the instrument. In fact, a cat walking about 3 feet away on the slab will set off the event alarm. The house is about 45 years old and the dirt under the slab may have settled somewhat, resulting in less support under the slab. Or maybe this is just the way it is. If I am working in the garage, I can plan on not seeing any small events during that time, and getting many false alarms. Also, walking on a brick sidewalk right outside the garage causes an alarm about half the time. It's not the best arrangement, but a satisfactory compromise. One day I hope to build an outside shed over stable granite and house my instruments there. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... At 09:02 PM 2/12/99 -0800, you wrote: >>>> Hello, I am in the midst of trying to set up a Lehman seismograph. However before I get started I want to determine the best spot in my house to set it up. Does anyone have experience with setting upn their seismograph in there garage. would the foot traffic be a problem? Fortunatly my house is on a cul-de-sac so there is not a whole lot of automobile traffic, but there are a lot of kids running around. Would it be more practical if I tried to place the sensor under my house in an insulated case, etc? Any help would be appreciated. Thanks in advance. Rudy Norvelle <<<<<<<< _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RLLaney@....... Subject: Re: Setting up a seismograph Date: Sat, 13 Feb 1999 11:38:34 EST Hi Rudy: I have a Lehman and SG seismograph on the floor of my double-car garage. I park my pickup within 3 feet of the instruments. They are very sensitive to foot traffic in the garage, movement of nearby trees, and even low flying helicoptors. When I move the truck in or out of the garage I get a "magnitude 1,000" event. When I am working in or near the garage I set the threshold on the SDR software at a maximum so that I do not record all this noise. Even with all of these noise sources, I was able to record more than 40 earthquakes and many quarry blasts last year and only missed one earthquake because I was working in or near the garage at the time. The way I look at it, seismology is a hobby for me--and a good one, too!--but it has to fit into my mode of living. I can't let the seismograph control me. So, I suggest that you go ahead and put yours in the garage and see how it works. You may be surprised. Regards, Bob Laney Herndon, VA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Steve Hammond Subject: Re: Fwd: origin of name of Lehman(n) sensor Date: Sat, 13 Feb 1999 17:12:36 -0800 Larry Cochrane wrote: > > FYI, Ken and I received this today.... > -Larry > > >Date: Thu, 11 Feb 1999 22:54:55 -0800 > >From: Ed Thelen > >Reply-To: ethelen@........ > >Organization: @Home Network > >X-Mailer: Mozilla 4.05 [en]C-AtHome0402 (Win95; I) > >To: kjn@.......... > >CC: cochrane@.............. > >Subject: origin of name of Lehman(n) sensor > > > >While reading > > http://www.seismicnet.com/info/homefaq.txt > > > >I saw question > >" > >Aside: > > No one seems to know if the Lehman(n) sensor is named after the > >author, > > James D. Lehman, or the famed Danish seismologist, Inge Lehmann, > >who > > published a paper in 1936, that postulated that the earth held > >an inner > > core estimated to be about the size of our moon within the outer > >core. > > If someone has some information on this please forward it to me > > so I can include it in the next update of the FAQ. > >(kjn@........... > >" > > > >I was editor of WASS (World Amateur Seismological Society) - RIP - > >in the early 1970s. > > 1) long period instruments - say from Springneither (sp) > > or of amateur construction were informally called > > "garden gate" or "Galtzin" (sp) style > > 2) I never heard of a "Lehman" style - > >so assume that the Lehman style is due to James D. > > > >-------------------- > > > >I cannot comprehend why someone would construct > >such a weak, complex double vertical post > >"Lehman" design using 3/4 inch tubing. > > - poor rigidity > > - ridiculous to analyze for vibrations > > - low frequency natural resonance > > > >The several instruments I constructed were of > >2 inch copper tubing and had a single > >vertical post - sturdy, quite rigid, > >high natural resonance frequency. > > > >Cheers > > Ed Thelen > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Steve Hammond Subject: Re: Fwd: origin of name of Lehman(n) sensor Date: Sat, 13 Feb 1999 17:18:39 -0800 Hi ken-- I came across the attached note the other day. It talks about James Lehman, posted by Bob Barns. Regards, Steve Larry Cochrane wrote: > > FYI, Ken and I received this today.... > -Larry > > >Date: Thu, 11 Feb 1999 22:54:55 -0800 Subject: James Lehman Date: Wed, 3 Jun 1998 20:32:25 -0400 From: robert barns <75612.2635@..............> Reply-To: PSN-L Mailing List To: PSN-L Mailing List Hi gang, The '79 Sci. Am. article on the Lehman seismograph attributed the design to James D. Lehman at James Madison U. in Harrisonburg, VA. Hotbot quickly gave me the URL of the school (www.jmu.edu/). This site is very attractive and complete. He is listed (with a photograph) in the Physics department along with his 'phone no. I called him to see if he is still interested in seismology. We had a long chat and he still runs his rig with a strip chart recorder. He is especially interested in microseisms. He modestly says that he never refers to the design as a Lehman but I think that he faces an impossible job if he ever tries to get us to change. He sez that he monitors the PSN e-mail and has been in touch with Larry in the past. His e-mail address is lehmanjd@........ Bob Barns Why do psychics have to ask you for your name? No one seems to know if the Lehman(n) sensor is named after the > >author, > > James D. Lehman, or the famed Danish seismologist, Inge Lehmann, > >who > > published a paper in 1936, that postulated that the earth held _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: files that crash winquake Date: Mon, 15 Feb 1999 09:46:11 +1300 hi all, tony and I are finding a lot of the files from one of the italian stations crash winquake when we try to view these files. is it just us 2 or are others having problems too.?? I have had to delete many of the files cuz they jst cannot be viewed here are some of the files in question...... 130299b.wq1 02/13/99 22:57:00 Sicily area (E) 140299b.wq1 02/14/99 22:57:00 Siracusa, Italy espri.wq1 02/14/99 patti's gulf 140299a2.wq1 02/14/99 13:31:00 Siracusa, Italy there are many others that also crash winquake i have no idea why its happening they just cause WQ to do an illegal operation jst on a sideline it would be nice if people could use the standard yr mth day eg. 990214a.lpn rather than as the ones above that have that opposite or using a placename for the file name. It makes life a lot easier for those of us who archive posted events, as when we are looking for/working with files in windows explorer etc, file manager, the files are then in chronological order. It is time consuming having to rename these files so they will appear in chronological order. Thanks :) Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: also meant to add Date: Mon, 15 Feb 1999 09:59:53 +1300 forgot to include I'm using WQ Version 2.5.2 32bit Tony is using Version 2.4 32 bit Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: horizontal tilt noise Date: Mon, 15 Feb 1999 01:01:23 -0600 (CST) Re: tilt sensitivity of horizontal seises: Regarding the recent question of finding a suitable site for a Lehman type horizontal seismometer: the problem is the extreme tilt sensitivity of a horizontal compared to a vertical sensor of the same period. In a nutshell, the tilt sensitivity of the vertical is proportional to the square of the tilt angle, while a horizontal is sensitive to the angle itself. Since we are dealing with small angles measured in radians, the squared value is much smaller. The formula for the tilt sensitivity of the horizontal pendulum: (which can be used to calibrate the displacement detector) z = (g * Tn^2 / 4 * pi^2) * phi where z is the horizontal displacement of the mass, Tn is the natural period, and phi is the tilt of the base at right angles to the boom, again measured in radians. g = 980cm/sec^2; z = cm. As an example: from experience in repeatedly adjusting the old S5100 for about 1mm of boom displacement: the base is 500 mm, so the tilt from 1/100 turn of the screw ( which is 0.008 mm) is 0.008/500 = 0.000016 radian. If Tn = 15 seconds, the mass will move 0.89 mm, which is close to what is observed. For the garage floor site, if we assume a 15 second horizontal seis and that the floor tilts by 0.001 radian (there are 2*pi radians in 360 degrees, so a radian is 57.3 degrees, so our floor is tilting only 0.057 degree. It doesn't sound like much, but the seismometer mass will move 55 mm because of it. Or if the output is 55 microns (displacement), the floor tilted one microradian. For a vertical seismometer, tilting the base will change the force of gravity that is normally exactly parallel to the force of the spring, reducing it slightly. The formula works out to: z = (g * Tn^2 / 8 * pi^2) * phi^2 For our floor tilt example above, the angle (0.001 radian) is squared, so the mass of the vertical will only move 27.5 MICRONS due to the same 0.001 rad. tilt. This effect is often used to absolutely calibrate vertical displacement sensors, such as gravimeters and VBB instruments. So it is clear that finding a suitable site for a long-period horizontal is much more demanding than for a vertical. Or conversely, if the only site around is the garage floor, try to build a vertical sensor. By way footnote: some have had success in siting instruments on an existing slab floor by sawing a square of it free from the surrounding floor. Large forces will still couple through the underlying clay, but some tilt noise is reduced. regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: New WinQuake beta release version 2.5.9 Date: Tue, 16 Feb 1999 00:28:13 -0800 Hi Everyone, I just released a new beta version of WinQuake. The version number is 2.5.9b. It can be downloaded using the following links: ftp://ftp.drnet.com/users/psn/software/wq259b_exe.zip ftp://ftp.drnet.com/users/psn/software/wq259b_full.zip or ftp://ftp.seismicnet.com/software/wq259b_exe.zip ftp://ftp.seismicnet.com/software/wq259b_full.zip The wq259b_full.zip file contains all of the files needed to update the current released WinQuake version. The wq259b_exe.zip file only contains the new exe file and one new data file. As with other beta release, you will need to unzip the file and copy all of the files over to your directory containing WinQuake. Make sure that you exit any running copies of WinQuake before copying the files. Heres what's new; Event File Integration: You can now double integrate an event file. This allows you to convert an event file recorded with an accelerometer too show displacement. ASCII Event File Format: In the last beta release I added the ability to save an event file in ASCII text. The new version can read in an event file in this text format. SEED/PEPP Mag Correction Number: Both SEED and PEPP volume / event files have sensor sensitivity information in the event file. I figured out how to use this information to come up with the equivalent magnitude correction number need by WinQuake to calculate Ms and Ml magnitudes. Some SEED volumes downloaded from dmc.iris.washington.edu are missing this information so I'm including a new data file called response.dat. WinQuake will search this file if the sensitivity information can't be found in the SEED volume. WinQuake will also search this file when reading an SAC binary event file. Old/New PSN format I simplified how WinQuake handles the old (type = 2) PSN event files. Before WinQuake kept track of the format and you could use the Modify dialog box to convert from the old to the new (type = 3) format. You could also, but I'm not sure why one would want too, convert from the new format to the old format. WinQuake now converts an old format event file to the new format when it reads it in. If you save the event file it will be in the new format. You can not convert a file from the new format to the old. Tables Dialog Box: The Tables dialog box has two new check boxes. If more then one event file window is opened, you can update all windows with the new depth, table to use and travel time table file name(S). The other check box allows you to automatically update the P and S location, if the event formation is present, after the Tables dialog box is closed. That's it. I'm running out of simple things to add to this release, so I'm going to try to finalize things and make an official release. If you have time I would appreciate it if you could try the new exe and let me know if you run into any problems. Regards, -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Information about the seismograph Date: Tue, 16 Feb 1999 21:08:35 -0700 Edgard- The best place to find out about low-cost seismic instrumentation is the Public Seismic Network (PSN) at . -Edward Edgard Gonzales Zenteno wrote: > Dear Sir > I need information about your instrument and cost > > Please send me the information to: egz@............ > University of San Agustin , Arequipa Peru. -- Edward Cranswick US Geological Survey Golden, CO 80401 USA TEL: 303-273-8609 FAX: 303-273-8600 -------------------------------------------------------------- Pymatuning Earthquake Field Headquarters (1998 Sep 27 ... ) Cianci's Motel, 395 Mercer Rd (HWY#58), Greenville, PA 16125 TEL: 724-588-8550 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: New web page Date: Wed, 17 Feb 1999 21:51:05 -0800 Hi Everyone, The other day Tom Leiper sent me a letter describing how he and his daughter built a seismograph system for a school project. With his permission I converted the Word document to HTML and placed it on my web site. The link is http://www.seismicnet.com/leiper/seismograph.html. It has photos of their sensor and chart recorder they made. They got the system going just in time to capture the 7.3 Santa Cruz Island event that happened about two weeks ago. Chelsea is on the PSN list, so they will get any comments sent to the list. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Giovanni Rotta" Subject: COMPLIMENTS TO TOM AND CHELSEA FROM ITALIAN STATIONS Date: Thu, 18 Feb 1999 18:34:37 +0100 A warm welcome to Tom and Chelsea !! Have the best compliments for the beatutiful work from the Italian PSN stations ! Giovanni Rotta Giovanni Rotta Via F. Pizzigoni, 10 33010 Resia (Udine) I Lat. 46.373 N Long. 13.305 E rottag@.......... http://www.geocities.com/~resianet/ingssr.htm _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: More vert seis theory Date: Sat, 20 Feb 1999 10:57:05 -0500 Hi seismo designers, I finally got going with a first-cut on the analysis of vertical seismo geometry, comparing the LaCoste "zero-length" spring design to the leaf-spring design. Also posted an error correction on my previous leaf-spring analysis. New files: Word for Windows file. (let me know if you'd like this also in "PDF" form. The drawings came out quite a bit better in the ".doc" file) CAD files related to above update Corrected for error in "max stress" column To be found at: http://members.home.net/nordgren/public/ The web site has been on and off for the past couple of days. Think they're just upgrading, so keep trying if you don't get through the first time. Good luck, Brett Nordgren bnordgren@.............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: chelsea@............ (Chelsea Leiper) Subject: Remote control programs Date: Sun, 21 Feb 1999 01:58:08 -0500 In reviewing the archives for this quarter I noticed some talk about remote control. I am in the business of manufacturing computerized medical diagnostic image display and capture systems and associated networking components. We have been performing remote control support and maintainence for over ten years on these systems. For DOS based systems I absolutely recommend the Norton Lambert "Close-Up" product which consists of two applications, "Support" which is the client and "Customer" which is the host. We use the RAS and DUN in Win95/98 along with custom applications which perform functions such as remote launching applications, displaying lists of running applications, killing applications and transferring files on the remote network, so we do not use the N-L product in these situations. Further, the versions of Close-Up since they added Windows were not as good as the original DOS product as the Windows GUI dramatically slowed things down, especially screen updates. But if you are doing DOS only on both sides, there is nothing better or faster. In particular, it has very nice "Automated Operations" functions that allow you to write a simple batch file to automatically connect up, send DOS commands (to either side) such as copying files and launching applications, and transfering files in both directions. We found that "PC Anywhere" had nowhere close to the capabilities in this area. In other words, you can (at the scheduled time) connect to the remote site, shutdown a running application, retrieve say, database files, launch a local application to process them, kill the local application, copy the processed files back to the remote location and re-start the remote application...as an example. It seems to me this would be perfect for a remote vacation home site running Emon, for instance. And that was the DOS version from ten years ago. Read about it at: http://www.nortonlambert.com/cupinfo2.htm Thanks for the compliments on Chelsea's seismo. Regards to all... Tom Leiper _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RLLaney@....... Subject: WinQuake beta releases Date: Sun, 21 Feb 1999 13:49:22 EST Hi Larry: I have gone over WinQuake beta release versions 2.5.7, 2.5.8 and 2.5.9. As usual, I am impressed with what a great piece of software this is--and it gets better! In going over the changes, a couple of questions came to mind. Double integration--I understand how this is used to get displacement if one has an accelerometer, but does integrating data from a Lehman or SG sensor have any physical meaning? If I understand correctly, the output from the SG and the Lehman varies in proportion to the pendulum's velocity and is represented by counts. Single integrating some of my event records results in some interesting looking graphs, but does this give even relative displacement? Double integration of these records would seem to have no physical meaning. FFT--What is the relation of the "a" scale on the FFT plot to the counts on the event record? (By the way, the addition of the display of the frequency and period with the mouse location is a neat addition to the FFT window.) I assume that the "a" scale of the FFT plot is related to amplitude of the event record, but I had expected it to be derived from the log of the counts on the event record. But, the values on the "a" scale are greater than what would be calculated from the logs of the count values from the event record. Am I missing something here? Thanks for the WinQuake upgrades. Bob Laney _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: large pacific quake NOW!!!! Date: Mon, 22 Feb 1999 14:20:08 +1300 surface waves at 01:15 UTC monday 22 feb Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: large pacific quake NOW!!!! Date: Sun, 21 Feb 1999 17:54:16 -0800 Using WinQuake's new event location feature I come up with the following numbers: Time of Origin: ~ 1:00:30 UTC Event Location: ~ -21.0 Lat. ~ 170.1 Long. Mag; ~ 6.7 Ms Too come up with these numbers I'm using several broadband sensors that I am monitoring over the Internet. See http://aslwww.cr.usgs.gov/Seismic_Data for more info. The stations I used where CTAO in Australia, TATO in Taiwan, KIP in Hawaii and BJT in China. It will be interesting to see how close I get to the numbers from NEIC. -Larry Cochrane Redwood City, PSN At 02:20 PM 2/22/99 +1300, you wrote: > > surface waves at 01:15 UTC monday 22 feb > > >Dave >Co-ordinator: >New Zealand >Public Seismic Network > Dave A. Nelson ZL4TBN > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > >http://www.seismicnet.com/dave/home.htm > >IF there indeed are other parallel universes... I can now rest in the >knowledge, that in at least one of them, I am filthy rich and drive a red >Ferrari > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Charlie Plyler Subject: Re: large pacific quake NOW!!!! Date: Sun, 21 Feb 1999 21:08:31 -0500 Looks like you are very close Larry. 22Feb1999 01:00:48.4 13.7S 166.9E 33 mb=5.8 A*NOR VANUATU ISLANDS 0132 22Feb1999`01:19' A SED PKP AZ= 71 SL=2.844 0126 22Feb1999 01:00:38.1 20.3S 169.9E 33 mb=5.7 A*NEI VANUATU ISLANDS 0120 Radius: 399 km Charlie Plyler Larry Cochrane wrote: > > Using WinQuake's new event location feature I come up with the following > numbers: > Time of Origin: ~ 1:00:30 UTC > Event Location: ~ -21.0 Lat. > ~ 170.1 Long. > Mag; ~ 6.7 Ms > > Too come up with these numbers I'm using several broadband sensors that I > am monitoring over the Internet. See http://aslwww.cr.usgs.gov/Seismic_Data > for more info. The stations I used where CTAO in Australia, TATO in Taiwan, > KIP in Hawaii and BJT in China. > > It will be interesting to see how close I get to the numbers from NEIC. > > -Larry Cochrane > Redwood City, PSN > > At 02:20 PM 2/22/99 +1300, you wrote: > > > > surface waves at 01:15 UTC monday 22 feb > > > > > >Dave > >Co-ordinator: > >New Zealand > >Public Seismic Network > > Dave A. Nelson ZL4TBN > > 24 Jensen St., > > Green Is., Dunedin, > > South Is.. New Zealand. > > > >http://www.seismicnet.com/dave/home.htm > > > >IF there indeed are other parallel universes... I can now rest in the > >knowledge, that in at least one of them, I am filthy rich and drive a red > >Ferrari > > > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@.............. with the body of the > >message: leave PSN-L > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "J. D. Cooley" Subject: Re: large pacific quake NOW!!!! Date: Sun, 21 Feb 1999 20:31:37 -0800 Wow! Someday I will get Windows 95/98 so I can do that!! VERY close, Larry. 99/02/22 01:00:32 21.52S 169.66E 33.0 6.4Ms A LOYALTY ISLANDS REGION At 05:54 PM 2/21/99 -0800, Larry Cochrane wrote: >Using WinQuake's new event location feature I come up with the following >numbers: > Time of Origin: ~ 1:00:30 UTC > Event Location: ~ -21.0 Lat. > ~ 170.1 Long. > Mag; ~ 6.7 Ms > >Too come up with these numbers I'm using several broadband sensors that I >am monitoring over the Internet. See http://aslwww.cr.usgs.gov/Seismic_Data >for more info. The stations I used where CTAO in Australia, TATO in Taiwan, >KIP in Hawaii and BJT in China. > >It will be interesting to see how close I get to the numbers from NEIC. > >-Larry Cochrane >Redwood City, PSN > > >At 02:20 PM 2/22/99 +1300, you wrote: >> >> surface waves at 01:15 UTC monday 22 feb >> >> >>Dave >>Co-ordinator: >>New Zealand >>Public Seismic Network >> Dave A. Nelson ZL4TBN >> 24 Jensen St., >> Green Is., Dunedin, >> South Is.. New Zealand. >> >>http://www.seismicnet.com/dave/home.htm >> >>IF there indeed are other parallel universes... I can now rest in the >>knowledge, that in at least one of them, I am filthy rich and drive a red >>Ferrari >> >> >>_____________________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email listserver@.............. with the body of the >>message: leave PSN-L >> > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: large pacific quake NOW!!!! Date: Mon, 22 Feb 1999 14:36:55 -0800 Well it looks like I was off by around 2 seconds for the time of origin, 75km for the Lat / Long and .3 Ms. Not bad for non-government work.... -Larry At 08:31 PM 2/21/99 -0800, J. D. Cooley wrote: >Wow! Someday I will get Windows 95/98 so I can do that!! VERY close, Larry. > >99/02/22 01:00:32 21.52S 169.66E 33.0 6.4Ms A LOYALTY ISLANDS REGION > >At 05:54 PM 2/21/99 -0800, Larry Cochrane wrote: >>Using WinQuake's new event location feature I come up with the following >>numbers: >> Time of Origin: ~ 1:00:30 UTC >> Event Location: ~ -21.0 Lat. >> ~ 170.1 Long. >> Mag; ~ 6.7 Ms >> >>Too come up with these numbers I'm using several broadband sensors that I >>am monitoring over the Internet. See http://aslwww.cr.usgs.gov/Seismic_Data >>for more info. The stations I used where CTAO in Australia, TATO in Taiwan, >>KIP in Hawaii and BJT in China. >> >>It will be interesting to see how close I get to the numbers from NEIC. >> >>-Larry Cochrane >>Redwood City, PSN > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: large pacific quake NOW!!!! Date: Mon, 22 Feb 1999 17:49:02 -0700 Larry- Amazing!!! -Edward Charlie Plyler wrote: > Looks like you are very close Larry. > > 22Feb1999 01:00:48.4 13.7S 166.9E 33 mb=5.8 A*NOR VANUATU > ISLANDS 0132 > 22Feb1999`01:19' A SED PKP AZ= 71 > SL=2.844 0126 > 22Feb1999 01:00:38.1 20.3S 169.9E 33 mb=5.7 A*NEI VANUATU > ISLANDS 0120 > Radius: 399 km > Charlie Plyler > > Larry Cochrane wrote: > > > > Using WinQuake's new event location feature I come up with the following > > numbers: > > Time of Origin: ~ 1:00:30 UTC > > Event Location: ~ -21.0 Lat. > > ~ 170.1 Long. > > Mag; ~ 6.7 Ms > > > > Too come up with these numbers I'm using several broadband sensors that I > > am monitoring over the Internet. See http://aslwww.cr.usgs.gov/Seismic_Data > > for more info. The stations I used where CTAO in Australia, TATO in Taiwan, > > KIP in Hawaii and BJT in China. > > > > It will be interesting to see how close I get to the numbers from NEIC. > > > > -Larry Cochrane > > Redwood City, PSN > > > > At 02:20 PM 2/22/99 +1300, you wrote: > > > > > > surface waves at 01:15 UTC monday 22 feb > > > > > > > > >Dave > > >Co-ordinator: > > >New Zealand > > >Public Seismic Network > > > Dave A. Nelson ZL4TBN > > > 24 Jensen St., > > > Green Is., Dunedin, > > > South Is.. New Zealand. > > > > > >http://www.seismicnet.com/dave/home.htm > > > > > >IF there indeed are other parallel universes... I can now rest in the > > >knowledge, that in at least one of them, I am filthy rich and drive a red > > >Ferrari > > > > > > > > >_____________________________________________________________________ > > > > > >Public Seismic Network Mailing List (PSN-L) > > > > > >To leave this list email listserver@.............. with the body of the > > >message: leave PSN-L > > > > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@.............. with the body of the > > message: leave PSN-L > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick US Geological Survey Golden, CO 80401 USA TEL: 303-273-8609 FAX: 303-273-8600 -------------------------------------------------------------- Pymatuning Earthquake Field Headquarters (1998 Sep 27 ... ) Cianci's Motel, 395 Mercer Rd (HWY#58), Greenville, PA 16125 TEL: 724-588-8550 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Bonnie Schafer" Subject: Fw: {EarthWaves} "CYBERSYSTEM" FOR EARTHQUAKE ENGINEERING SIMULATION Date: Tue, 23 Feb 1999 19:26:40 -0800 Bonnie the crafty crafter -----Original Message----- > >Embargoed until 2:00 P.M., ESTMedia contact: February 23, 1999 >Joel Blumenthal NSF PR 99-13 >(703) 306-1070/jblument@.............. contact:Priscilla Nelson >(703) 306-1361/pnelson@....... > > NSF TO ESTABLISH "CYBERSYSTEM" > FOR EARTHQUAKE ENGINEERING SIMULATION > > A top National Science Foundation [NSF] official today described >to a House >subcommittee how the NSF plans to use information technology [IT] to >establish a >cyber Network for Earthquake Engineering Simulation [NEES]. > Testifying before the House Committee on Science' Subcommittee on >Basic >Research, Joseph Bordogna, NSF acting deputy director, said that NEES >"will >change the face of earthquake engineering." His statement was part of >testimony in favor of re-authorizing the National Earthquake Hazards >Reduction >Program [NEHRP]. > NEES "will use IT to serve a critical national need (reducing and >mitigating effects of earthquakes): to help save lives and money; and >to make more >efficient use of government's investment in science and engineering," >Bordogna said. >NSF is seeking $7.7 million in its fiscal 2000 budget request for the >first year of aplanned five-year, $81.9 million program for NEES. >Bordogna told the subcommittee, chaired by Rep. Nick Smith (R-Mich.), >that NEES, like NEHRP, was initiated in response to a mandate from >Congress to take >stock of the nation's experimental and testing capability in >earthquake >engineering. > NEES will use a computer network to bring "a complete collection >of >state-of-the-art facilities under one `virtual roof,'" Eugene Wong, >NSF's assistant director >for engineering, said. "It will provide remote access to users, and >make a >complete system of testing and experimental facilities available to >the entire >earthquake engineering community." Networking software will enable the >system >to use models and databases to develop model-based simulation, Wong >added. >More than 30 U.S. institutions currently have some kind of >experimental >earthquake engineering facilities. These include shake tables for >earthquake >simulations, reaction walls for pseudodynamic testing, geotechnical >centrifuges >for testing soils during earthquakes, and floor reaction systems. >NEES funds would be used to: create new shake tables and upgrade >existing >shaketables; build centrifuges and Tsunami testing tanks; build new >reaction walls, >load simulators and response modifiers; and create field test >facilities (i.e. mobile >equipment, field sites and post-quake labs). Funds will also provide >for system >integration and to ensure completion of all corefacilities. Bordogna >stated that NEES >can serve as an educational tool for students and the public, and as >the primary >repository of earthquake engineering physical experiments and data. He >added that >NEES also will leverage public and private investments in the $100 >billion-a-year IT >industry by using existing software and making effective use of the >high-speed >networking infrastructure that is one of NSF's most successful >ventures. > -NSF- > > >^^ To UNSUBSCRIBE: Send "unsubscribe earthwaves" to majordomo@........... >^^ To SUBSCRIBE: Send "subscribe earthwaves" to majordomo@........... >^^ To SUBSCRIBE ANOTHER: Type "subscribe earthwaves name@........." >^^ All commands should be placed in body of message, with no quotes >^^ Auto-approval occurs when confirmation email is returned by subscriber >^^ Check current EQ reports: http://www.earthwaves.com/current.html > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Malcolm Purves Subject: Re: Fw: {EarthWaves} "CYBERSYSTEM" FOR EARTHQUAKE ENGINEERING SIMULATION Date: Wed, 24 Feb 1999 05:24:21 +0000 Errr, pardon me, but would you care to edit that so as we can see the meaning of it, please ? or paraphrase perhaps. or did you send it tongue-in-whatsit ? Malcolm. Bonnie Schafer wrote: > > Bonnie the crafty crafter > -----Original Message----- > > > >Embargoed until 2:00 P.M., ESTMedia contact: February 23, 1999 > >Joel Blumenthal NSF PR 99-13 > >(703) 306-1070/jblument@.............. contact:Priscilla Nelson > >(703) 306-1361/pnelson@....... > > > > NSF TO ESTABLISH "CYBERSYSTEM" > > FOR EARTHQUAKE ENGINEERING SIMULATION > > > > A top National Science Foundation [NSF] official today described > >to a House Big Snip _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Bonnie Schafer" Subject: Re: Fw: {EarthWaves} "CYBERSYSTEM" FOR EARTHQUAKE ENGINEERING SIMULATION Date: Wed, 24 Feb 1999 21:59:23 -0800 Hi, I sent it tongue and cheek--so to speak--just thought it would be of interest. Bonnie the crafty crafter _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Walt Williams" Subject: PSN-L: {EarthWaves} a comment Date: Thu, 25 Feb 1999 01:55:13 -0800 Hello Bonnie, I liked it. Walt Williams, 99.02.25 OSR ================================== ------- Forwarded Message Follows ------- Reply-to: PSN-L Mailing List From: "Bonnie Schafer" To: "PSN-L Mailing List" Subject: Re: Fw: {EarthWaves} "CYBERSYSTEM" FOR EARTHQUAKE ENGINEERING SIMULATION Date: Wed, 24 Feb 1999 21:59:23 -0800 Hi, I sent it tongue and cheek--so to speak--just thought it would be of interest. Bonnie the crafty crafter _________________________________________________________________ ____ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: I need to know about.... Date: Thu, 25 Feb 1999 10:16:25 -0700 Rani- > How many seismographs are needed in each location (presumably of an > earthquake struck region) to gain sufficient info? The short answer to your question is: If one wants to understand how earthquakes damage buildings, and if a building on one side of the street collapsed but a building on the other side of the street did not collapse, there need to be strong motion recordings from both sides of the street, i.e., there should at least be a seismograph in every structure at risk. I also have longer answers to your question. If you need more information, please let me know. Have you seen the Public Seismic Network, for example, ? -Edward rani ramanathan wrote: > I was wondering if you could help me on this question: > How many seismographs are needed in each location(presumably of an > earthquake struck region) to gain sufficient info?I would really > appreciate it if you would be able to help me on this question. > Thanking you,Aashlesha V. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: DXF Request to S-T M Date: Thu, 25 Feb 1999 13:25:39 -0500 Sean-Thomas, I'm making slow progress on the math to predict a leaf-spring vertical's free period, based on the spring dimensions and the system geometry. I'm hoping to possibly get some clues as to how to go about setting up the geometry for infinite (or very long) free period. Using some "pretend" numbers, I was able to cobble up a design that predicts zero net restoring force at its operating point, but I am still suspicious that there are errors in my method. So now I'd like to see if theory and practice can be made to agree (and if not, why not). Do you have any sort of .DXF file of a configuration for which you have measured the free period? I would scale off the dimensions (AutoSketch 5), use them and the mass value to compute a period and then see if the calculation bears any relation to the actual performance. One thing that might be coming out of this is that there may possibly not be any great advantage to tilting the spring force line back toward the support like LaCoste. But I need to look at the numbers a whole lot more before I'd ever want to state that for certain. Many thanks, Brett _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Francesco Subject: LARGE QUAKE: RUSSIA Date: Thu, 25 Feb 1999 22:09:13 +0100 Org time: 18:58:34 Ms 6.1 Loc.: Lake Baikal Region - Russia I.E.SN. PSN ITALY _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: leaf spring and period Date: Fri, 26 Feb 1999 00:40:39 -0600 (CST) Brett, The drawing of the seismometer on the web site at: http://www.eas.slu.edu/People/STMorrissey/ stmfigs.html" The STM-8 Seis: Figures, Schematics, Drawings shows the current configuration and dimensions of the leaf spring vertical. It clearly shows the relative positions of the spring supports. As the upper support of the spring is moved toward the hinges, the period approaches instability. Small adjustments of a few mm back away from the hinge will result in stable periods of 20 seconds or more. At this point the relative stiffness of the hinges themselves becomes a consideration, but I have no estimate of the force they contribute. But the mechanical period is not a major concern for the VBB instrument, since it only affects the damping term. Longer mechanical periods only enhance the thermal instability. I am currently operating the Beta unit at 8 seconds. But any desired instrument performance is possible even with a moderate (and stable) mechanical period. By setting the feedback capacitor Cp at 20 ufarad, the operational damping at 0.707, and the displacement gain r at 10^6, all of which keep the output level constant, I can set the operating period To anywhere from 1 second to 960 seconds by simply selecting the integrator period TI and calculating the required value for the proportional resistor Rp and the integral resistor RI. (At 960 seconds these values exceed 6 megohms with a 120 second integrator). A 3-pole switch can select the values. This provides a handy feature in that a 1-second response is very useful for making adjustments, and being able to select an intermediate period for some circumstances like during windy periods can be advantageous. Some commercial VBBs use a relay to change these values to temporarily configure a 1-second response during the operation of the centering motor. I don't want to discourage you from your curiosity about the leaf spring behavior. But the beauty of the triple feedback VBB is that a long mechanical period is not an important concern as long as it is stable. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Bonnie Schafer" Subject: Re: PSN-L: {EarthWaves} a comment Date: Fri, 26 Feb 1999 22:37:59 -0800 Hi, thanks glad you did. Bonnie the crafty crafter _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Steve Hammond Subject: [Fwd: QED NUMBER 9-057] Date: Sat, 27 Feb 1999 17:17:00 -0800 QEDPOST - earthquake alert list some of you may have not received this or known about it. Regards, Steve Hammond From: Steve Hammond Subject: [Fwd: EQ MAG 5.8 LAKE BAYKAL REGION, RUSSIA] Date: Sat, 27 Feb 1999 17:18:40 -0800 BIGQUAKE information Also, some of you may not have received this or known about it. Regards, Steve Hammond From: S-T Morrissey Subject: BIGQUAKE listing Date: Sat, 27 Feb 1999 13:32:59 -0600 (CST) Re. BIGQUAKE mailing from NEIS. Thanks to Steve for informing the PSN re the Bigquake update. In reviewing the latest event, it comes to mind that maybe, someday, over-the-rainbow, etc., PSN station data will be used in real time by NEIS for event location via some automatic retrieval setup. I am always pleased when the St. Louis Univ. "Billiken" network of VBB stations is fully used: (in the Lake Baykal event: JFWS,CBKS,CCM,WCI,WVT,MIAR were used). It would definitely give satisfaction to a PSN station operator to see their data used. On the other hand, the Mb. 3.8 Main event had somewhat poor coverage, which is where the PSN may eventually be able to make a significant contribution. Realizing a near real-time response would be a major challenge. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Linux people? Date: Sat, 27 Feb 1999 20:05:47 +0000 If there are any Linux people on the PSN list you might be interested in this. I have been attempting(!) to write a device driver for Larry's ADC board for a while. I'm really not a really good programmer so it's very difficult. If anyone wants to help out that would be great. Why would you want to use Linux instead of DOS? Tons of networking options. You could set it up so that it automatically ftps your event files to your web site every time it records one or just set it up as a full time ftp server on the internet. There's so many possibilities... I talked with another guy about this and he suggested Real time Linux could increase the sampling rate a LOT. I'm using regular non-Real time Linux to write it. I found a development kit for it which makes it almost possible for me to understand. I also have the book Linux Device Drivers. They both concentrate on generating modules so I don't think they'd work in a monolithic kernel? I tested the sample modules for LDDK and it works as far as I can tell. I have a /dev/adc file now. I don't think LDDK support interrupts, but the book does explain them in almost excessive detail. There are tons of other ADC drivers to look at and that might be my next step. I'm missing some example code of how to talk to the driver. I can cat /dev/adc or echo "" > /dev/adc, but I don't know how to call a function inside the driver from a C program. I just thought there might be some interest, Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Walt Williams" Subject: PSN-L: Linux people? Date: Sat, 27 Feb 1999 18:17:37 -0800 Hi Greg, Couple months back the Linux Journal published an informative article about writing device drivers in......LINUX! :)) Check it out. Walt Williams, 99.02.27 OSR p.s. Did I ever say thanks for the PCB program advice you gave me? (it was good advice, and solved the problem, thank you :) ========================================== ------- Forwarded Message Follows ------- Date: Sat, 27 Feb 1999 20:05:47 +0000 From: Greg To: "psn-l@.............." Subject: Linux people? Reply-to: PSN-L Mailing List If there are any Linux people on the PSN list you might be interested in this. I have been attempting(!) to write a device driver for Larry's ADC board for a while. I'm really not a really good programmer so it's very difficult. If anyone wants to help out that would be great. Why would you want to use Linux instead of DOS? Tons of networking options. You could set it up so that it automatically ftps your event files to your web site every time it records one or just set it up as a full time ftp server on the internet. There's so many possibilities... I talked with another guy about this and he suggested Real time Linux could increase the sampling rate a LOT. I'm using regular non-Real time Linux to write it. I found a development kit for it which makes it almost possible for me to understand. I also have the book Linux Device Drivers. They both concentrate on generating modules so I don't think they'd work in a monolithic kernel? I tested the sample modules for LDDK and it works as far as I can tell. I have a /dev/adc file now. I don't think LDDK support interrupts, but the book does explain them in almost excessive detail. There are tons of other ADC drivers to look at and that might be my next step. I'm missing some example code of how to talk to the driver. I can cat /dev/adc or echo "" > /dev/adc, but I don't know how to call a function inside the driver from a C program. I just thought there might be some interest, Greg _________________________________________________________________ ____ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: Re: leaf spring and period Date: Sat, 27 Feb 1999 22:31:09 -0500 Sean-Thomas, Many thanks for your update on the design. Indeed, I was using your "Vertseis" gif's to get the dimensions. As a test, I had been calculating the mass needed for equilibrium, and was getting values about fifteen percent low. Thought the problem was either with my math or with the beam dimensions I was entering. But, once I made the spring 3.5" wide (instead of 3") the mass required came out within 1/2% of 0.5 kg, so now I'm really hopeful that was the answer. Indeed, I agree, the beam free oscillation characteristics have virtually no effect on the velocity response with the feedback turned on. I was more interested in the benefits from getting the net restoring force down. As it stands, at DC, with +/- 9 V out of Op Amp A4 through 107k Ri in parallel with 581k Rp, there are available somewhere around +/- 100 microamps to the feedback coil; less with higher resistance values. Times 13 N/A that's roughly +/- 130 dynes force available at DC. With no help from the geometry (3.9 sec period), for +/- 1mm at the mass I think you would need something in the range of +/- 260 dynes to staticaly control the beam at its extremes, just to overcome the effective spring constant. A 20 sec period gets you down to about 4.9 dynes / mm, which is now well within the available feedback force at DC. By carefully tweaking the geometry on the computer (probably way better than one could do in practice) I can compute a net beam restoring force of about 0.2 dynes / mm (100 sec?). Even with a more realizable level of tuning, the feedback should still easily be able to control the beam at 0 Hz over the full range of motion. Also, reducing the effective spring constant should significantly increase the loop gain at DC and at the very low frequencies where it is needed, while avoiding any effects at the higher frequencies that might start loop oscillations. I don't think this helps in the slightest with spring creep or thermal variations, but I'm also almost certain that it won't hurt, either. Again, thanks for your comments. Brett At 12:40 AM 2/26/99 -0600, you wrote: >Brett, >The drawing of the seismometer on the web site at: > >http://www.eas.slu.edu/People/STMorrissey/ >stmfigs.html" The STM-8 Seis: Figures, Schematics, Drawings > >shows the current configuration and dimensions of the leaf spring >vertical. It clearly shows the relative positions of the spring >supports. As the upper support of the spring is moved toward the hinges, >the period approaches instability. Small adjustments of a few >mm back away from the hinge will result in stable periods of >20 seconds or more. At this point the relative stiffness of the >hinges themselves becomes a consideration, but I have no estimate >of the force they contribute. > >But the mechanical period is not a major concern for the VBB >instrument, since it only affects the damping term. Longer mechanical >periods only enhance the thermal instability. I am currently operating >the Beta unit at 8 seconds. > >But any desired instrument performance is possible even with a moderate >(and stable) mechanical period. By setting the feedback capacitor Cp at >20 ufarad, the operational damping at 0.707, and the displacement gain >r at 10^6, all of which keep the output level constant, I can set the >operating period To anywhere from 1 second to 960 seconds by simply >selecting the integrator period TI and calculating the required value >for the proportional resistor Rp and the integral resistor RI. (At 960 >seconds these values exceed 6 megohms with a 120 second integrator). >A 3-pole switch can select the values. This provides a handy feature in >that a 1-second response is very useful for making adjustments, and being >able to select an intermediate period for some circumstances like >during windy periods can be advantageous. Some commercial VBBs use >a relay to change these values to temporarily configure a 1-second >response during the operation of the centering motor. > >I don't want to discourage you from your curiosity about the leaf spring >behavior. But the beauty of the triple feedback VBB is that a long >mechanical period is not an important concern as long as it is stable. > >Regards, >Sean-Thomas > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: PSN-L: Linux people? Date: Sun, 28 Feb 1999 06:42:36 +0000 Walt Williams wrote: Hey-low, > Couple months back the Linux Journal published an informative > article about writing device drivers in......LINUX! :)) I've been reading it for about a year now. I subscribe. I don't remember seeing the article, but maybe I wasn't looking for it or I skipped the article. I'll have to dig through the old issues. > p.s. > Did I ever say thanks for the PCB program advice you gave me? > (it was good advice, and solved the problem, thank you :) I doubt it was me that gave the advice. However it's not unlike me to talk over my own head. I only played with the one program. I forget the name of it. It was for Windows 95. The program was free, but the only way to get a PCB out it was to send it to the company that wrote the software. James wrote: > might try here > http://www.slashdot.org/ I read it almost every day. Usually twice. A lot of the articles are just links to other news sites. > or maybe a user group is close to you > http://www.linux.org/users/groups/usa/index.html I was one of the first members of the local group. My ISP is the server for the mailing list. I never went to a meeting, but I doubt it would help. Tucson is a almost a technological vaccum. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: Hinge effects Date: Sun, 28 Feb 1999 12:31:09 -0500 Sean-Thomas, You were questioning the effect of the beam hinges on the leaf-spring vertical, so last night I took a look at what their effect might be. To date, I've been ignoring the effect of the hinges. I think the effective spring constant at the mass, due to the hinges is given by K = (E W t^3) /(12 b^2 L) lb/in (x 17,638 to get dynes / mm) E is the elastic modulus of spring bronze = 1.5E7 lb/in^2 T is the leaf thickness = 0.005 in W is the total width of all leaves = 4 x 3/8 = 1.5 in b is the distance from the hinge to the mass, assumed here = 14.72 in L is the free-air length of the leaves. (big assumption) = .04 in L is the hardest to know. It depends mainly on how much the outside corners of the angles that support the leaves have been rounded off. You might get a rough idea by measuring the gap between the angles at a 45 degree angle with a feeler gauge and then multiplying by the square-root of 2. Multiplying the numbers out gives 477 dynes / mm, I think. Much stiffer than I'd expected! The natural period would = sqrt(1974 / k) or about 2 sec in this example. That's the effect of the hinges alone. Since k is proportional to 1 / t^3, using thinner material should lower k enormously. However, with thinner material, I'd start to think about possible buckling of the horizontal hinges, since the force on the beam hinge is up and to the left in your drawing. If you wanted to not worry about that, you might try a right-left mirror image on the hinge support angles and move the vertical support column 1.5 in to the right. That way, the horizontal leaves would be in tension. Even .001" shim stock should be strong enough. 5 lb force / (0.75 in x .001) is under 7000 psi. Comfortable, though you wouldn't want to bang it around too hard. I'm pretty sure that the hinge effect can also be compensated out by the geometry, but I suspect that having a low spring constant to begin with is even better. Regards, Brett _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: RLLaney@....... Subject: Undocumented event?? Date: Sun, 28 Feb 1999 15:16:03 EST I recorded an event on 2/27/99 at 17:17:42 UTC, or at least it appeared to be an event. The "P" arrival was definitely above the noise and the "S" arrival was very strong. The estimated distance to the "event" was about 300 km. Sometimes surface waves from distant quakes can appear as something more local, but there were no large distant events reasonably prior to this time. Any suggestions from anyone? Thanks. Bob Laney Herndon, VA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "J. D. Cooley" Subject: Re: Undocumented event?? Date: Sun, 28 Feb 1999 14:21:02 -0800 I noticed this on the global seismograms and was waiting for an ageny to report it, but no luck. The International Data Center has the following info: 1999/02/27 07:13:49.8 62.78S 169.50E mb 4.2 Balleny Islands Region I have a nice seismogram from New Zealand I can e-mail to anyone that would like it. And, thank you Bob for including the date and time in UTC. "JD" At 03:16 PM 2/28/99 EST, Bob Laney wrote: >I recorded an event on 2/27/99 at 17:17:42 UTC, or at least it appeared to be >an event. The "P" arrival was definitely above the noise and the "S" arrival >was very strong. The estimated distance to the "event" was about 300 km. >Sometimes surface waves from distant quakes can appear as something more >local, but there were no large distant events reasonably prior to this time. >Any suggestions from anyone? > >Thanks. > >Bob Laney >Herndon, VA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Xmas in Dominica: EQs, Volcanoes, and the PSN Date: Sun, 28 Feb 1999 19:34:52 -0700 Jody Bourgeois* and Edward Cranswick will present a talk: "Xmas in Dominica: Earthquakes, Volcanoes, and the Public Seismic Network" on Tuesday, 2 March 1999, at 1:00 PM, in the 3rd Floor Conference Room (Room 318), USGS Golden. *visiting scientist from the University of Washington -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: Re: Undocumented event?? Date: Mon, 1 Mar 1999 15:40:22 +1300 At 14:21 28/02/99 -0800, you wrote: >I noticed this on the global seismograms and was waiting for an ageny to >report >it, but no luck. The International Data Center has the following info: >1999/02/27 07:13:49.8 62.78S 169.50E mb 4.2 Balleny Islands Region >I have a nice seismogram from New Zealand I can e-mail to anyone that would >like it. >"JD" yes please would appreciate a copy Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Lehman pickup coil and magnet. Date: Sun, 28 Feb 1999 21:09:52 -0800 Hi Everyone, I'm looking for some advice on a replacement for the pickup coil I have been selling. As some of you know I have been selling a coil and magnet combination to help people build their sensor without having to worry about winding a coil. I have a picture of the coil and magnet at http://psn.quake.net/coilmag.html. The problem is I can no longer find the relay I have been using for the coil. While the relays I have been using are new, I have been getting them from a local surplus electronics store. Well I went to the well, so too speak, one too many times and they no longer have the part. The insignia on the relay looks like they where made by Grayhill. Grayhill no longer makes electromechanical relays so I can buy them from a normal distributor. The nice thing about the old 220vac relay coil was it had a lot of turns, over 10k with a dc resistance around 8 to 9k, and fit nicely within the 22 lb horseshoe magnet. I have looked at some other high voltage high resistance relays, but they have a much smaller coil. This produces a much smaller output when placed on my Lehman using the existing 22 lb magnet. I was wondering if anyone had any ideas on what I could offer as a coil / magnet combination. Something I can get off the shelf. I may have too check into having a coil winding shop make some for me. The problem maybe getting a suitable bobbin for them to wind the coil on. With the low quantity order like mine, cost per coil maybe a problem. I was getting the relays for under $5.00... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Mark Robinson" Subject: Re: Lehman pickup coil and magnet. Date: Mon, 1 Mar 1999 18:40:43 +1300 Hi Larry Try looking at coils for electrical contactors from an electrical wholesaler (or whatever you have over there). regards Mark -----Original Message----- From: Larry Cochrane To: psn-l@.............. Date: Monday, 1 March 1999 18:30 Subject: Lehman pickup coil and magnet. >Hi Everyone, > >I'm looking for some advice on a replacement for the pickup coil I have >been selling. As some of you know I have been selling a coil and magnet >combination to help people build their sensor without having to worry about >winding a coil. I have a picture of the coil and magnet at >http://psn.quake.net/coilmag.html. > >The problem is I can no longer find the relay I have been using for the >coil. While the relays I have been using are new, I have been getting them >from a local surplus electronics store. Well I went to the well, so too >speak, one too many times and they no longer have the part. The insignia on >the relay looks like they where made by Grayhill. Grayhill no longer makes >electromechanical relays so I can buy them from a normal distributor. > >The nice thing about the old 220vac relay coil was it had a lot of turns, >over 10k with a dc resistance around 8 to 9k, and fit nicely within the 22 >lb horseshoe magnet. I have looked at some other high voltage high >resistance relays, but they have a much smaller coil. This produces a much >smaller output when placed on my Lehman using the existing 22 lb magnet. > >I was wondering if anyone had any ideas on what I could offer as a coil / >magnet combination. Something I can get off the shelf. I may have too check >into having a coil winding shop make some for me. The problem maybe getting >a suitable bobbin for them to wind the coil on. With the low quantity order >like mine, cost per coil maybe a problem. I was getting the relays for >under $5.00... > >-Larry Cochrane >Redwood City, PSN > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: WinQuake beta releases - FFT Date: Mon, 01 Mar 1999 00:07:22 -0800 At 01:49 PM 2/21/99 EST, RLLaney@....... wrote: [snip] >FFT--What is the relation of the "a" scale on the FFT plot to the counts on >the event record? (By the way, the addition of the display of the frequency >and period with the mouse location is a neat addition to the FFT window.) I >assume that the "a" scale of the FFT plot is related to amplitude of the event >record, but I had expected it to be derived from the log of the counts on the >event record. But, the values on the "a" scale are greater than what would be >calculated from the logs of the count values from the event record. Am I >missing something here? I'm not 100% sure what the "a" scale represents when doing an FFT. If you do an FFT of a pure sine wave you get about 1/2 of the input A/D counts. The Log display displays the same data as the linear display, only in a different scale. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Thomas W Leiper Subject: Re: Larry's SOS call for pickup coil Date: Mon, 1 Mar 1999 04:17:06 -0500 Larry - I was thinking about making one using a Teflon tape pipe sealant dispenser with snap-on cover. The core would make a good bobbin, and you could snap the cover back on when done. It also has a decent diameter so the counter-emf problem I mentioned in Chelsea's seismo article would be reduced. You could also use small cylindrical magnets in the solenoid configuration. It would be no big deal to rig up a DC motor and mandrel for a winding rig. In fact you could just take the motor and foot pedal off an old sewing machine (who uses THEM anymore!), and have a machine shop (or me) turn down a mandrel for you in about 5 minutes. Just give me the motor shaft dimensions and the ID & width of the tape core you select, and I'll make you one because I'm a nice guy. Then, if you really wanted to sell a high quality coil, you could separate the winding layers with the Teflon tape you would otherwise throw out, although the first roll would probably be enough Teflon until you retire. The ones I have, have great dimensions. The "bobbin" ID (size of the hole) is 1". The OD is 2" and the width is 5/8". The plastic thickness is about 1/16", so the ID of the windings would be 1 1/8" and the width 1/2". Same OD. I am SURE that Sean can respond in less than a nanosecond with the formula for calculating the number and resistance of turns by wire gauge (domestic and foreign) for sixteen different winding tensions, including tapered tension reduction rates, which would reduce compression and distortion of the inner windings...Sean? On another note, for those who do not have the right kind of hailer on their boat to make the pickup I described on Chelsea's seismo, I have found a cheap and available substitute which works just as well. Use a magnet-mount base for a CB/Ham mobile antenna. Turn the iron bar so that its diameter halves the distance between the ID and the OD of the circular magnet in the mount. You can put an inner "shoulder" on it that is the ID of the magnet so it stays centered. It won't go anywhere. After removing the antenna mount and bolt from the plate, you can put in a 3/8" X 4 carriage bolt sticking out the other side to go through the boom, a locknut, and into a counterweight. Adios... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Ken Navarre Subject: Re: Larry's SOS call for pickup coil Date: Mon, 1 Mar 1999 08:30:11 -0800 (PST) On Mon, 1 Mar 1999, Thomas W Leiper wrote: > Larry - I was thinking about making one using a Teflon tape pipe sealant > dispenser with snap-on cover. (snip) > You could also use small cylindrical magnets in the solenoid > configuration. Hummm, now that I think about it this seems like a really good solution for us to wind our own solenoids! I picked up a few "cow magnets" from a local feed store that would fit nicely into the core. Cow magnets are shoved down a cow's gullet so that they will snatch onto any metal wire that the cow eats as it meanders along in it's profession of making methane... Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Nick & Sophie Caporossi Subject: SOS call for pickup Coils Date: Mon, 01 Mar 1999 13:17:31 -0500 Hi Thomas and Larry: Teflon tape pipe sealant dispenser is a good idea. I have made a few coils by using the dispenser from one pound lead that is used by plumbers. I cut a portion from the center and glue the sides together. The ID is about 1 inch and the OD is about 2 and 1/8 inches. I've used a fishing spinner to wind the coil. The bobbin puts about 20 turns across the reel. It goes very fast with a little care you can put on about 500 turn a minute. On the question of magnets, AC Hardware sells horse shoe magnets, they are a little small, about 20 pound pull. For that size magnet they run about $7.00. Has any one used a flat magnet. Some of them are quite strong, and easy to come by. Nick _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Ian Smith Subject: Re: SOS call for pickup Coils Date: Mon, 01 Mar 1999 08:36:12 -1000 I got a rare earth magnet from http://www.sciplus.com/cgi-bin/basket/920313088.27/home.html V strong, though irregular in shape, a bit like a stone. It might just fit inside a 1 inch ID former. They also have loads of other "interesting" items. I Smith _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: coil.info Date: Mon, 1 Mar 1999 13:45:35 -0600 (CST) Thomas, Yes, I have been winding coils for many years, including making large quadrupole focusing magnets for the cyclotron some 30 years ago. For these, every bend of every turn had to be exactly positioned, and the resistance of the #10 wire of each pole had to come out identical. Since you asked, there is an appendix in the Riedesel paper... "Limits of Sensitivity of Inertial Seismometers with Velocity Transducers and Electronic Amplifiers", by Mark A. Riedesel, Robert D. Moore, and John A. Orcutt; Bulletin of the Seismological Society of America, Vol. 80, No 6, December 1990. .... that has all the parameters of seismometer coils explained; (the main conclusion is that the generator constant increases only with the square root of the coil resistance, everything else being equal). Also, there is considerable info in "Reference Data for Radio Engineers", whatever edition you have, on coils and magnets. By the way though, my interest in VBB sensors precludes the need for high resistance coils, which don't work in the transfer function. The coil and magnet of a 10" speaker works just fine if the boom is long enough to allow the arc of the coil movement to not jam in the magnet. The generator constant of this 8-ohm coil is about 12 N/A (Newtons/Ampere) or Volts/meter/second. A large 500-ohm coil (from the S-5100 long-period seismometer), has a constant of 96 N/A in the 3"dia x 4" long annular magnet. The output difference of X 8 is easily made up for with a quiet amplifier, like the OP-27. And for one who uses "THEM" sewing machines anymore, the one at the back of the electronics desk here still keeps the socks darned and the jeans sewed up, if I can find it among the parts and assemblies of various seismometer configurations. Its bobbin winder has been pressed into making miniature calibration coils by using plastic bobbins to work with 1/8" dia rod magnets. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: George Harris Subject: Re: Lehman pickup coil and magnet. Date: Mon, 01 Mar 1999 12:33:02 +0000 Larry Cochrane wrote: > > Hi Everyone, > > I'm looking for some advice on a replacement for the pickup coil I have > been selling. As some of you know I have been selling a coil and magnet > combination to help people build their sensor without having to worry about > winding a coil. I have a picture of the coil and magnet at > http://psn.quake.net/coilmag.html. > Larry, I have purchased similar coils from Cosmo Corp. in Cleveland. The phone number is 216-861-5594. They have a large catalog of square, round and other shapes with or without terminals. As an example they have about 60 different coils with an ID between .381 and .400. OD varies from .8 to 1.3 and lengths from .19 to 1.7. If you wish to call me (bay area now) I will be glad to look up a number which would fit. Other Ids go from .09 to 3.4 George Harris 707-751-1936 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "James M Hannon" Subject: Re: Lehman pickup coil and magnet. Date: Mon, 1 Mar 1999 15:20:42 -0600 Larry, If you want to keep the cost to a minimum I would stay with 240 volt relay coils. There are a lot of surplus 240 volt relays on the market for around $2. It has been my experience that most relays can be easily dissasembled to extract the coil. Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Erich Kern" Subject: Relay Coils Date: Mon, 1 Mar 1999 13:35:38 -0800 Larry, Hosfelt Electronics in Stuebenville, Ohio has a half dozen relays in their 1999 catalog ( pages 41, 42, 43 ) which match the description of what you're looking for. Some examples: cat. no. 45-613, 240V coil, 9110 ohms, $1.95 each; cat. no. 45-433, 208 volt coil, 36,000 ohms, $3.95 each; cat. no. 45-327, 115 V coil, 11,000 ohms, $2.75 each and 3 others with coil resistances above 10K ohms. Their toll free order number is 800-524-6464 or 888-264-6464. I don't see a website or e-mail address anywhere in their catalog, but they take credit card phone orders and you could ask for a catalog at the same time. They're 3 hours ahead of us, so it might have to wait until tomorrow. Regards, Erich ********************************************************* Please visit our web site at: http://fqs.dconn.com ********************************************************* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: twleiper@........ Subject: Re: coil.info Date: Mon, 1 Mar 1999 16:47:05 -0500 Sean, There will truly be a gigantic "unrecoverable block" in the database of seismological and miscellaneous knowledge if and when you pass on to that great seismometer down under. I just wonder, will your casket be set on a proper pier? If so, which orientation would you choose, because that is what I'll use for Chelsea's next instrument... Tom _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: pouellette Subject: Re: Lehman pickup coil and magnet. Date: Mon, 01 Mar 1999 21:19:56 -0500 Check in the WW Grainger catalog. Thats where I got mine. If you need it, I'll get you a stock number.. Pete Ouellette Larry Cochrane wrote: > Hi Everyone, > > I'm looking for some advice on a replacement for the pickup coil I have > been selling. As some of you know I have been selling a coil and magnet > combination to help people build their sensor without having to worry about > winding a coil. I have a picture of the coil and magnet at > http://psn.quake.net/coilmag.html. > > The problem is I can no longer find the relay I have been using for the > coil. While the relays I have been using are new, I have been getting them > from a local surplus electronics store. Well I went to the well, so too > speak, one too many times and they no longer have the part. The insignia on > the relay looks like they where made by Grayhill. Grayhill no longer makes > electromechanical relays so I can buy them from a normal distributor. > > The nice thing about the old 220vac relay coil was it had a lot of turns, > over 10k with a dc resistance around 8 to 9k, and fit nicely within the 22 > lb horseshoe magnet. I have looked at some other high voltage high > resistance relays, but they have a much smaller coil. This produces a much > smaller output when placed on my Lehman using the existing 22 lb magnet. > > I was wondering if anyone had any ideas on what I could offer as a coil / > magnet combination. Something I can get off the shelf. I may have too check > into having a coil winding shop make some for me. The problem maybe getting > a suitable bobbin for them to wind the coil on. With the low quantity order > like mine, cost per coil maybe a problem. I was getting the relays for > under $5.00... > > -Larry Cochrane > Redwood City, PSN > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: SW6079@....... Subject: Re: Lehman pickup coil and magnet. Date: Tue, 2 Mar 1999 00:57:44 EST Larry, I am involved in the heating and a/c trade and use 220 vac relays all the time. If you want to give me a phone call some eve. I'm pretty sure I could find a suitable substitute. Mike aka sw6079@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "David A. Nelson" Subject: For Bob Lewis, cant get u direct Date: Tue, 2 Mar 1999 19:37:10 +1300 oops i posted to the events server instead of here sorry everyone else for the clutter Bob, i updated ur email addy on the psn database but when i e-mailed u to say thanks the e-mail addy was rejected as not existing so not sure what the problem is >Hi Dan...I have a new ISP and a new e-mail address: blewis@.............. >Please update this on my station listing, thanks! all done Bob, thanks for the update Dave above is the addy u send me in the text of the letter but i just noticed that the mail u sent came from blewis5@ ........ please clarify for me thanks Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://www.seismicnet.com/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Francesco" Subject: SDR TIME PROBLEM Date: Tue, 2 Mar 1999 13:10:36 +0100 Hi to all. I have in the last days a serious problem with SDR: =20 sometimes the programm doesn't hook the clock of the pc and therefore = it marks a different time, many minutes or straight times in less. I = don't use the wwv but the European signal DCF77 that enters, through a = a/d board in the serial port of the pc ( 350 pentium) and rule the = clock of the bios. All the functions of the SDR time-clock are disabled. = The same thing happens in the pc that doesn't have DCF77 also.=20 For a good work I must reset the program and so it returns to mark the = right time. Any suggestion? Regards Francesco Nucera I.E.S.N PSN ITALY
Hi to all.
I have in the last days a serious = problem with=20 SDR: 
sometimes the programm  doesn't  hook the clock = of the=20 pc  and therefore it marks a different time,  many minutes or = straight=20 times in less. I don't use the wwv but the European signal DCF77  = that=20 enters, through a  a/d  board in the serial port of the pc ( = 350=20 pentium) and rule the clock of the bios. All the functions of the SDR = time-clock=20 are disabled.  The same thing  happens in the pc that doesn't = have=20 DCF77 also.
For a good work  I must = reset  the=20 program and so it returns to mark the right time.
 
Any suggestion?
 
Regards
Francesco Nucera    I.E.S.N PSN=20 ITALY
 
 
From: "Giacomo" Subject: R: SDR TIME PROBLEM Date: Tue, 2 Mar 1999 13:38:39 +0100 Francesco cos'=E8 SDR? Incomicia a spiegarmi queste cose tecniche che mi farebberono piacere a = saperle. In questi giorni come vedo c'=E8 movimento pure leggero dalle nostre = parti x te cosa significa un normale liberamento di energia di semplice = routine o altro? Ciao G. -----Messaggio originale----- Da: Francesco A: PSN-L Mailing List Data: marted=EC 2 marzo 1999 13.10 Oggetto: SDR TIME PROBLEM =20 =20 Hi to all. I have in the last days a serious problem with SDR: =20 sometimes the programm doesn't hook the clock of the pc and = therefore it marks a different time, many minutes or straight times in = less. I don't use the wwv but the European signal DCF77 that enters, = through a a/d board in the serial port of the pc ( 350 pentium) and = rule the clock of the bios. All the functions of the SDR time-clock are = disabled. The same thing happens in the pc that doesn't have DCF77 = also.=20 For a good work I must reset the program and so it returns to mark = the right time. =20 Any suggestion? =20 Regards Francesco Nucera I.E.S.N PSN ITALY =20 =20
Francesco cos'è = SDR?
Incomicia a = spiegarmi queste=20 cose tecniche che mi farebberono piacere a saperle.
In questi = giorni come vedo=20 c'è movimento pure leggero dalle nostre parti x te cosa significa = un=20 normale liberamento di energia di semplice routine o altro?
Ciao
G.
-----Messaggio = originale-----
Da:=20 Francesco <franuc@......>
A: = PSN-L Mailing=20 List <psn-l@..............>
D= ata:=20 martedì 2 marzo 1999 13.10
Oggetto: SDR TIME=20 PROBLEM

Hi to all.
I have in the last days a = serious problem=20 with SDR: 
sometimes the programm  doesn't  hook = the=20 clock of the pc  and therefore it marks a different time,  = many=20 minutes or straight times in less. I don't use the wwv but the = European=20 signal DCF77  that enters, through a  a/d  board in = the=20 serial port of the pc ( 350 pentium) and rule the clock of the bios. = All the=20 functions of the SDR time-clock are disabled.  The same = thing =20 happens in the pc that doesn't have DCF77 = also.=20
For a good work  I must = reset  the=20 program and so it returns to mark the right time.
 
Any suggestion?
 
Regards
Francesco Nucera    I.E.S.N PSN=20 ITALY
 
 
From: Edgard Gonzales Zenteno Subject: seismograph for local earthquake Date: Tue, 02 Mar 1999 15:01:36 -1200 Hi Everyone, I'm looking for an instrument for the registration of local earthquakes and microseismicity. Edgard Gonzales egz@............ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: GeE777@....... Subject: Re: seismograph for local earthquake Date: Tue, 2 Mar 1999 17:34:30 EST In a message dated 3/2/99 12:05:22 PM Pacific Standard Time, egz@............ writes: << I'm looking for an instrument for the registration of local earthquakes and microseismicity. Edgard Gonzales egz@............ __ >> That is what I do. I use a vertical and two horizontal 8 HZ geophones into a MPLI hardware and software.interface. George Erich Seismic Exploration Consultant P. O. Box 2011, Norwalk, CA 90651, U. S. A. Phone (562) 868-6013 e-mail GeE777@....... 33 53.90N 118 04.53W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Xmas in Dominica: EQs, Volcanoes, and the PSN Date: Tue, 02 Mar 1999 16:38:07 -0700 Wayne- Jody Bourgeois and I gave a one-hour-long, informal talk about our trip to Dominica that was quite like the trip itself: a mixture of geology, interesting and good people, seismology, and beautiful country. We started with a brief introduction about the volcanic activity in the neighboring island of Montserrat, including a "Full color clip, showing the advancement of the flow down the Tar River Valley and out into the sea, set to the music of Arrow a local Montserratian musician who has written songs about the interaction of the islanders and the volcano. 4.7M QuickTime (w/sound)" , to set the stage for what the people of Dominica had heard about constantly for three years prior to the onset of seismic activity southern Dominica in late 1998. Jody summarized the seismo-tectonics of the Caribbean and geology of Dominica. She showed slides of places on the island we visited: our trek to Boiling Lake led by Clem & Madhava, Soufriere and Scots Head during our stay with Andre' & Joyce, sites along the Portsmouth-Roseau commute that you and Dolores took us several times, and of course, the triumphal DARC Boxing Day party at Clement & Hetty's house when the first earthquake was recorded with the Dominica PSN seismograph you assembled from the many PSN-contributed parts. I concluded with a short on-line demonstration of the Dominica PSN website , including some regional and local records and the notice: INCREASE IN EARTHQUAKE ACTIVITY - March 02, 1999. From 05:00 UTC March 02, 1999, Earthquake activity has increased in the south of Dominica. Between 05:00 UTC and 22:00 UTC, the PSN seismograph has recorded in excess of 58 earthquakes, many of which were felt by local residents. This swarm is ongoing and the larger quakes will soon be posted on this site. (which Jody likes because it supports her hypothesis of increased seismic activity in Dominica during the full-moon) -Edward Wayne Abraham J73WA wrote: > Edward > > I have placed your email in the News and Developments section on our > website. I would be greatful if both you and Jody could send me a note > on the outcome so I can add it to the site. > > Wayne -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Re: Xmas in Dominica: EQs, Volcanoes, and the PSN Date: Tue, 02 Mar 1999 22:44:07 -0400 Edward I will place your last email concerning the informal talak in the News and Developments section of our website. As for Jody's observation, she is bang on the money. I have been noticing that seismic activity increases between the last quarter and full moon. According to the local radio, 64 quakes were recorded by the SRU between Midnight and 2:00pm today but I will have to listen tomorrow morning for the update. We counted 58 up till 5:00pm but there were a few extremely small ones which we deliberately left out. It was like carnival for me today. I really feasted on the beautiful seismograms that were recorded on the system. I may have to split up the day's data into 4 6-hour segments and place 4 files on the website. Keep checking out the site http://www.freeyellow.com/members6/dominicapsn/ for updates. Wayne _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Angel Rodriguez Subject: Re: Larry's SOS call for pickup coil Date: Wed, 3 Mar 1999 18:48:25 -0500 At 04:17 AM 03/01/1999 -0500, you wrote: >Larry - I was thinking about making one using a Teflon tape pipe sealant >dispenser with snap-on cover. The core would make a good bobbin, and you >could snap the cover back on when done. What a great idea. I wound a coil on a telfon tape bobbin today and learned the following. I used #34 wire. When I was done it weighed a bit less that a 1/4 pound and had a resitance of 489 ohms. The problem I encountered was that the sides of the bobbin expaned out as I wrapped and the the thickness at the OD is about 1/8 inch wider than at the ID. I will still use it but I will support the sides on the next one. regards, Angel _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Ted Blank Subject: EMON 7.3a beta version available Date: Wed, 3 Mar 1999 20:15:56 -0800 (PST) A new version of EMON is available for any intrepid beta testers willing to give it a try. Here are the new features: *** What's new in EMON Version 7.3 *** EMON 7.3 has several new features to help automate routine tasks. All of the new features are controlled by entries in the OPT file. *** Support for scheduled actions You can now schedule up to two independent actions (usually, to run a BAT file) at predetermined intervals. The intervals can be DAILY, EVEN, ODD, MON, TUE, WED, THU, FRI, SAT, or SUN. In addition you can choose the hour of the day at which each of the two actions is performed. *** Support for event-driven actions You can now specify a command or BAT file to be run each time a quake file is saved to disk. You may specify up to two parameters to be passed to the BAT file. The parameters can be made up of the following items: String Expansion Type Example ------ ---------------- --------------- ---------- %P = path to save files alphanumeric C:\QUAKES\ %N = file name alphanumeric 980804AN.FOX %D = date mm/dd/yy 08/04/98 %T = time hh:mm:ss 05:33 %MO = month numeric 08 %DA = date numeric 04 %YR = year numeric 98 %H = hour numeric 23 %M = minute numeric 59 %X = maximum data value numeric 4096 n = any non-blank char alphanumeric (),/.- etc. Ex: %P%N would expand to C:\QUAKES\980804AN.FOX %N,%X " " " 980804AN.FOX,4096 (if 4096 was max value) %N/%H:%M " " " 980804AN.FOX/13:30 (if quake time = 13:30) *** Support for special "After Multi-file Quake" activity removed In some earlier versions of EMON, users were given the capability to specify one set of actions to perform after each data file was saved, and a different set of actions after a multiple-file quake occured. The support for special multi-file actions has been removed. *** New A/D boards supported Two additional A/D boards are supported. Their OPT file values are: 14 = Axiom Technology AX5210-PG 15 = ANA290 12-bit 8 Chan Prog Gain *** Support for "keyboard locking" Some schools running EMON under Win95 reported that students were inadvertently exiting EMON by pressing F10 to return to Windows, rather than using Ctrl-Esc to bring up the task bar. Also, some students who were not part of the Quake Tracker team at the school played around with the computer enough that significant data files were missed. With EMON 7.3a you can specify three new options in EMON.OPT. LockKeyboardPassword = xxxx 'None = keyboard cannot be locked 'xxxx = 4-character string to lock keybd UnlockKeyboardPassword = yyyy 'None = n/a 'yyyy = 4-character string to unlock kbd InitialKeyboardState = LOCKED 'Locked or Unlocked upon pgm startup By typing either of the four character passwords, the keyboard can be locked or unlocked without stopping EMON. When the keyboard is locked, a message is displayed at the bottom of the screen inviting the user to enter the unlock password. Typing the lock password re-locks the keyboard, including all F1-F10 keys. Passwords are not displayed as they are typed. Let me know if you are interested in trying out the beta version. If enough people want it, I may ask Larry to put it on the web site. Ted Blank San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Francesco Subject: LARGE QUAKE IN SOUTHERN IRAN Date: Thu, 04 Mar 1999 08:57:51 +0100 At 05.38.26 Ms 6.4 Loc.: 28.31N 51.17E deepth 33.0 SOUTHERN IRAN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Francesco Subject: LARGE AFTERSHOCK IN IRAN Date: Thu, 04 Mar 1999 09:14:31 +0100 07.26.58 MS 5.9~ The same location of main event Francesco Nucera, I.E.S.N. PSN Italy _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Francesco" Subject: IRANIAN SEISMIC CRISIS . ANOTHER LARGE AFTERSHOCK Date: Thu, 4 Mar 1999 11:34:58 +0100 09:51:17 M 5.8 ~ Southern Iran The aftershock continues with many events: 5 > M 5.0 - 3 > m 5.5 From local Tv reporter the notice of many victims and iniureds. Francesco Nucera I.E.S.N. PSN Italy
09:51:17
M 5.8 ~
Southern Iran
 
The aftershock continues with many = events: 5=20 > M 5.0 -  3 > m 5.5
From local Tv reporter the notice of = many=20 victims and iniureds.
 
Francesco Nucera
I.E.S.N. PSN = Italy
From: Larry Cochrane Subject: Re: WinQuake beta releases Date: Thu, 04 Mar 1999 13:42:40 -0800 At 01:49 PM 2/21/99 EST, Bob Laney wrote: >Hi Larry: > >I have gone over WinQuake beta release versions 2.5.7, 2.5.8 and 2.5.9. As >usual, I am impressed with what a great piece of software this is--and it gets >better! In going over the changes, a couple of questions came to mind. > >Double integration--I understand how this is used to get displacement if one >has an accelerometer, but does integrating data from a Lehman or SG sensor >have any physical meaning? If I understand correctly, the output from the SG >and the Lehman varies in proportion to the pendulum's velocity and is >represented by counts. Single integrating some of my event records results in >some interesting looking graphs, but does this give even relative >displacement? Double integration of these records would seem to have no >physical meaning. From what I understand, if you integrate data taken with an accelerometer you get velocity. If you integrate again, you get displacement. So if you integrate the output of a Lehman that is outputting velocity, you should get displacement. I have no idea what one gets if you double integrate velocity. Since the SG sensor's pickup uses displacement, the output below the period of the pendulum is measuring acceleration. On my SG board I have two outputs. One is the direct output, more or less, of the pendulum. There is a 1 pole high pass filter and a 6 pole low pass filter in the signal path. The other output has an integrator in the signal path, as well as some high and low pass filtering, so this output should be velocity below the period of the pendulum. Since teleseismic events have most of their information (at the recording site) below the ~1 second period of the pendulum, this output should be velocity. In fact, if you record both outputs of the SG sensor and integrate, using WinQuake, the "high frequency" or non-integrated output and compare it to the "low frequency" or integrated output, you will see a very similar event file for teleseismic events. I have a more detailed question coming up on the integrating the output of my accelerometer and comparing it to my Lehman. Since the accelerometer has a known output, I should be able to use it to calibrate my other sensor in my house. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: WinQuake beta releases Date: Thu, 04 Mar 1999 19:23:26 -0700 (MST) On Thu, 4 Mar 1999, Larry Cochrane wrote: > At 01:49 PM 2/21/99 EST, Bob Laney wrote: > >Double integration--I understand how this is used to get displacement if one > >has an accelerometer, but does integrating data from a Lehman or SG sensor > >have any physical meaning? > > I have no idea what one gets if you double integrate > velocity. We can sure find out now that Larry added this feature! Anyone tried it yet??? ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Norman Davis WB6SHI Subject: Re: EMON 7.3a beta version available Date: Fri, 05 Mar 1999 08:43:23 -0800 I have looked all over. Where is that program at? At 08:15 PM 3/3/99 -0800, you wrote: >A new version of EMON is available for any intrepid beta testers >willing to give it a try. Here are the new features: > >*** What's new in EMON Version 7.3 *** > >EMON 7.3 has several new features to help automate routine tasks. All of >the new features are controlled by entries in the OPT file. > >*** Support for scheduled actions > >You can now schedule up to two independent actions (usually, to run a BAT >file) at predetermined intervals. The intervals can be DAILY, EVEN, ODD, >MON, TUE, WED, THU, FRI, SAT, or SUN. In addition you can choose the hour >of the day at which each of the two actions is performed. > > >*** Support for event-driven actions > >You can now specify a command or BAT file to be run each time a quake >file is >saved to disk. You may specify up to two parameters to be passed to the >BAT file. The parameters can be made up of the following items: > > > String Expansion Type Example > ------ ---------------- --------------- ---------- > %P = path to save files alphanumeric C:\QUAKES\ > %N = file name alphanumeric 980804AN.FOX > %D = date mm/dd/yy 08/04/98 > %T = time hh:mm:ss 05:33 > %MO = month numeric 08 > %DA = date numeric 04 > %YR = year numeric 98 > %H = hour numeric 23 > %M = minute numeric 59 > %X = maximum data value numeric 4096 > n = any non-blank char alphanumeric (),/.- etc. > > Ex: %P%N would expand to C:\QUAKES\980804AN.FOX > %N,%X " " " 980804AN.FOX,4096 (if 4096 was max value) > %N/%H:%M " " " 980804AN.FOX/13:30 (if quake time = 13:30) > > >*** Support for special "After Multi-file Quake" activity removed > >In some earlier versions of EMON, users were given the capability to >specify one set of actions to perform after each data file was saved, >and a different set of actions after a multiple-file quake occured. The >support for special multi-file actions has been removed. > >*** New A/D boards supported > >Two additional A/D boards are supported. Their OPT file values are: > >14 = Axiom Technology AX5210-PG >15 = ANA290 12-bit 8 Chan Prog Gain > > >*** Support for "keyboard locking" > >Some schools running EMON under Win95 reported that students were >inadvertently exiting EMON by pressing F10 to return to Windows, rather >than using Ctrl-Esc to bring up the task bar. Also, some students who >were not part of the Quake Tracker team at the school played around with >the computer enough that significant data files were missed. > >With EMON 7.3a you can specify three new options in EMON.OPT. > > LockKeyboardPassword = xxxx 'None = keyboard cannot be locked > 'xxxx = 4-character string to lock >keybd > > UnlockKeyboardPassword = yyyy 'None = n/a > 'yyyy = 4-character string to >unlock kbd > > InitialKeyboardState = LOCKED 'Locked or Unlocked upon pgm startup > >By typing either of the four character passwords, the keyboard can be locked >or unlocked without stopping EMON. When the keyboard is locked, a message >is displayed at the bottom of the screen inviting the user to enter the >unlock password. Typing the lock password re-locks the keyboard, including >all F1-F10 keys. Passwords are not displayed as they are typed. > > >Let me know if you are interested in trying out the beta version. If >enough people want it, I may ask Larry to put it on the web site. > >Ted Blank >San Jose, California > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Bonnie Schafer" Subject: Date: Fri, 5 Mar 1999 13:20:19 -0800 Bonnie the crafty crafter _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: bc Subject: Re: WinQuake beta releases Date: Fri, 05 Mar 1999 23:03:33 -0500 At 07:23 PM 3/4/99 -0700, you wrote: >On Thu, 4 Mar 1999, Larry Cochrane wrote: >> At 01:49 PM 2/21/99 EST, Bob Laney wrote: >> >Double integration--I understand how this is used to get displacement if one >> >has an accelerometer, but does integrating data from a Lehman or SG sensor >> >have any physical meaning? >> >> I have no idea what one gets if you double integrate >> velocity. > If you double intergrate velocity you get displacement. > We can sure find out now that Larry added this feature! Anyone tried it >yet??? > >****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > http://www.public.asu.edu/~hernlund/ > >****************************************************************************** > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: WinQuake beta releases Date: Sat, 06 Mar 1999 08:56:07 -0800 bc I disagree.If one double integrates acceleration one gets displacement. Maybe integrating displacement over time (double integrating velocity) is a form of work? regards Barry bc wrote: > At 07:23 PM 3/4/99 -0700, you wrote: > >On Thu, 4 Mar 1999, Larry Cochrane wrote: > >> At 01:49 PM 2/21/99 EST, Bob Laney wrote: > >> >Double integration--I understand how this is used to get displacement > if one > >> >has an accelerometer, but does integrating data from a Lehman or SG sensor > >> >have any physical meaning? > >> > >> I have no idea what one gets if you double integrate > >> velocity. > > > > If you double intergrate velocity you get displacement. > > > We can sure find out now that Larry added this feature! Anyone tried it > >yet??? > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: bc Subject: Re: WinQuake beta releases Date: Sat, 06 Mar 1999 12:16:31 -0500 You are absolutely right, I stand corrected. Thanks for getting me back on track though. Sometimes mouth wags before brain is engaged At 08:56 AM 3/6/99 -0800, you wrote: >bc > I disagree.If one double integrates acceleration one gets displacement. >Maybe >integrating displacement over time (double integrating velocity) is a form >of work? > > regards > Barry > > >bc wrote: > >> At 07:23 PM 3/4/99 -0700, you wrote: >> >On Thu, 4 Mar 1999, Larry Cochrane wrote: >> >> At 01:49 PM 2/21/99 EST, Bob Laney wrote: >> >> >Double integration--I understand how this is used to get displacement >> if one >> >> >has an accelerometer, but does integrating data from a Lehman or SG >sensor >> >> >have any physical meaning? >> >> >> >> I have no idea what one gets if you double integrate >> >> velocity. >> > >> >> If you double intergrate velocity you get displacement. >> >> > We can sure find out now that Larry added this feature! Anyone tried it >> >yet??? >> > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Earthworm Helicorder Date: Sat, 06 Mar 1999 09:37:51 -0800 I think someone mentioned this before because the name sounds familiar. UNR Univ Nevada Reno has a cool realtime display of a particular sensor in Nevada. Does anyone know if there is access to similar sites for other locations? I got to them thru the USGS menlo park site. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: George Bush Subject: Re: WinQuake beta releases Date: Sat, 06 Mar 1999 11:12:47 -0800 At 11:03 PM 3/5/99 -0500, you wrote: >At 07:23 PM 3/4/99 -0700, you wrote: ....clip... > >If you double intergrate velocity you get displacement. > >> We can sure find out now that Larry added this feature! Anyone tried it >>yet??? >> Yes! My instrument is located in the garage in the back corner. When I drive in or out of the garage I record a big spike of noise. I used the double intergration feature to look at the displacement of the slab (actually the tilt of the slab). The result was beautiful, all the spikey noise was integrated out and the resultant curve was a flat line that then sloped-down and levelled off as the car arrived and the slab deflected. Now if I could just figure out what the calibration is. George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: Earthworm Helicorder Date: Sat, 06 Mar 1999 19:21:54 +0000 barry lotz wrote: > in Nevada. Does anyone know if there is access to similar sites for > other locations? I got to them thru the USGS menlo park site. Just how realtime do you mean? I've seen a lot that are updated every 15-30 minutes. Here's a list of some of those: http://aslwww.cr.usgs.gov/Seismic_Data/heli.htm I've also seen a sensor in Southern California somewhere that was showing data through a Java program. Here's some of those: http://benioff.geol.wwu.edu/seismolet.html http://www.ifg.tu-clausthal.de/java/seis/SeisDemApp.html (appears broken) I can't find the one that I tried before. Maybe it's in LA? ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Re: Earthworm Helicorder Date: Sat, 06 Mar 1999 13:07:14 -0800 Greg It looks like a realtime trace. I'm sure it's delayed a little due to processing. I will check it if I see a teleseismic event coming in on my sensor. Try: > http://www.seismo.unr.edu/ftp/pub/ichinose/JavaWorm/WormWavesApplet.html > Regards Barry Greg wrote: > Just how realtime do you mean? I've seen a lot that are updated every > 15-30 minutes. Here's a list of some of those: > > Greg
      It looks like a realtime trace. I'm sure it's delayed a little due to processing. I will check it if I see a teleseismic event coming in on my sensor. Try: 
http://www.seismo.unr.edu/ftp/pub/ichin
ose/JavaWorm/WormWavesApplet.html


Regards
 Barry
 

Greg wrote:

Just how realtime do you mean? I've seen a lot that are updated every
15-30 minutes. Here's a list of some of those:
 
 
From: Edward Cranswick Subject: Re: Fw: {EarthWaves} "CYBERSYSTEM" FOR EARTHQUAKE ENGINEERING SIMULATION Date: Sat, 06 Mar 1999 15:33:41 -0700 Bonnie- I think the mass distribution of strong motion recorders would be a much more effective means of "reducing and mitigating effects of earthquakes". It is better to record what the Earth is doing in fact, rather than to simulate what you think it might do. -Edward Bonnie Schafer wrote: > Bonnie the crafty crafter > -----Original Message----- > > > >Embargoed until 2:00 P.M., ESTMedia contact: February 23, 1999 > >Joel Blumenthal NSF PR 99-13 > >(703) 306-1070/jblument@.............. contact:Priscilla Nelson > >(703) 306-1361/pnelson@....... > > > > NSF TO ESTABLISH "CYBERSYSTEM" > > FOR EARTHQUAKE ENGINEERING SIMULATION > > > > A top National Science Foundation [NSF] official today described > >to a House > >subcommittee how the NSF plans to use information technology [IT] to > >establish a > >cyber Network for Earthquake Engineering Simulation [NEES]. > > Testifying before the House Committee on Science' Subcommittee on > >Basic > >Research, Joseph Bordogna, NSF acting deputy director, said that NEES > >"will > >change the face of earthquake engineering." His statement was part of > >testimony in favor of re-authorizing the National Earthquake Hazards > >Reduction > >Program [NEHRP]. > > NEES "will use IT to serve a critical national need (reducing and > >mitigating effects of earthquakes): to help save lives and money; and > >to make more > >efficient use of government's investment in science and engineering," > >Bordogna said. > >NSF is seeking $7.7 million in its fiscal 2000 budget request for the > >first year of aplanned five-year, $81.9 million program for NEES. > >Bordogna told the subcommittee, chaired by Rep. Nick Smith (R-Mich.), > >that NEES, like NEHRP, was initiated in response to a mandate from > >Congress to take > >stock of the nation's experimental and testing capability in > >earthquake > >engineering. > > NEES will use a computer network to bring "a complete collection > >of > >state-of-the-art facilities under one `virtual roof,'" Eugene Wong, > >NSF's assistant director > >for engineering, said. "It will provide remote access to users, and > >make a > >complete system of testing and experimental facilities available to > >the entire > >earthquake engineering community." Networking software will enable the > >system > >to use models and databases to develop model-based simulation, Wong > >added. > >More than 30 U.S. institutions currently have some kind of > >experimental > >earthquake engineering facilities. These include shake tables for > >earthquake > >simulations, reaction walls for pseudodynamic testing, geotechnical > >centrifuges > >for testing soils during earthquakes, and floor reaction systems. > >NEES funds would be used to: create new shake tables and upgrade > >existing > >shaketables; build centrifuges and Tsunami testing tanks; build new > >reaction walls, > >load simulators and response modifiers; and create field test > >facilities (i.e. mobile > >equipment, field sites and post-quake labs). Funds will also provide > >for system > >integration and to ensure completion of all corefacilities. Bordogna > >stated that NEES > >can serve as an educational tool for students and the public, and as > >the primary > >repository of earthquake engineering physical experiments and data. He > >added that > >NEES also will leverage public and private investments in the $100 > >billion-a-year IT > >industry by using existing software and making effective use of the > >high-speed > >networking infrastructure that is one of NSF's most successful > >ventures. > > -NSF- > > > > > >^^ To UNSUBSCRIBE: Send "unsubscribe earthwaves" to majordomo@........... > >^^ To SUBSCRIBE: Send "subscribe earthwaves" to majordomo@........... > >^^ To SUBSCRIBE ANOTHER: Type "subscribe earthwaves name@........." > >^^ All commands should be placed in body of message, with no quotes > >^^ Auto-approval occurs when confirmation email is returned by subscriber > >^^ Check current EQ reports: http://www.earthwaves.com/current.html > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: Water Valley, MS quake Date: Sat, 06 Mar 1999 15:42:47 -0700 Charlie- I showed your record to Mark Meremonte yesterday when we were looking at the data recorded by USGS instruments in Memphis. Unfortunately, our instruments did not start recording until the day after the Water Valley event. -Edward Charlie Rond wrote: > 2/25/99 Event > > ------------------------------------------------------------------------ > Name: 990225CA.RM1 > 990225CA.RM1 Type: unspecified type (application/octet-stream) > Encoding: base64 > > ------------------------------------------------------------------------ > > Charlie Rond -\/\--Public Seismic Network-Memphis > http://gandlf.ceri.memphis.edu/~rond/psn > -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Greg Subject: Re: Earthworm Helicorder Date: Sun, 07 Mar 1999 01:14:03 +0000 barry lotz wrote: > It looks like a realtime trace. I'm sure it's delayed a little > due to processing. I will check it if I see a teleseismic event coming > in on my sensor. Try: > > > http://www.seismo.unr.edu/ftp/pub/ichinose/JavaWorm/WormWavesApplet.html It's a simulation of an event for now. The date in the windows is 1998, unless that's incorrect. It's says that they hope to make it real-time in the future. It's neat though. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: WinQuake beta releases Date: Sat, 06 Mar 1999 18:24:45 -0700 Barry- Well, integrating or any other kind of analytic math has always been alot of work for me to understand, so forgetting about the niceties of calculus for a second, I will give the cartoon version of the ground motion story. This presentation will be in terms of average values of ground motions, and not instantaneous values, i.e., dx and dt. Thus it will be wrong in terms of accurate scaling, i.e., the constant multiplier that determines the scalar values (the '=' represents proportionality rather than equality), but the units will indicate what is happening during integration. Velocity, V, is displacement, X, divided by time, T: V = X / T e.g., cm / s Acceleration, A, is velocity divided by time: A = V / T = (X / T) / T e.g., cm / s / s = cm / s**2 In effect, when we integrate over time, we multiply by time. So if we integrate acceleration once, we obtain velocity: A * T = ( V / T ) * T = V e.g., cm / s If we integrate velocity, we obtain displacement: V * T = ( X / T ) * T = X e.g., cm If we integrate displacement, X * T = M e.g., cm * s or cm-s where M scales with seismic moment (which is derived from the classical definition of angular moment in terms of force applied along a moment arm of given length, and which is akin to, but not the same as, seismic energy, i.e., work), when X is ground displacement. In a perfect world, which is what geophysicists like to assume about the Earth (geologists believe the Earth simply is), simple slip on a fault produces a single-sided displacement pulse in the far-field (at a distance away from the fault that is an order-of-magnitude greater than the length of fault that slipped): as the seismic wave propagates past the observer, the ground goes up and then goes down (or reverse), returning essentially to its pre-event position. The logarithm of the peak amplitude of that pulse is proportional to the Richter local magnitude (ML). The duration (i.e., half-period) of that single-sided pulse is proportional to the length of the fault that slipped. The area under that pulse, i.e., the integral of the displacement, is proportional to the seismic moment of the earthquake. So, Singly-integrated A = V Singly-integrated V = X Singly-integrated X = M Doubly-integrated A = X Doubly-integrated V = M Doubly-integrated X = ? In the interest of not confusing anybody, particularly myself, I will not continue any further. -Edward barry lotz wrote: > bc > I disagree.If one double integrates acceleration one gets displacement. Maybe > integrating displacement over time (double integrating velocity) is a form of work? > > regards > Barry > > bc wrote: > > > At 07:23 PM 3/4/99 -0700, you wrote: > > >On Thu, 4 Mar 1999, Larry Cochrane wrote: > > >> At 01:49 PM 2/21/99 EST, Bob Laney wrote: > > >> >Double integration--I understand how this is used to get displacement > > if one > > >> >has an accelerometer, but does integrating data from a Lehman or SG sensor > > >> >have any physical meaning? > > >> > > >> I have no idea what one gets if you double integrate > > >> velocity. > > > > > > > If you double intergrate velocity you get displacement. > > > > > We can sure find out now that Larry added this feature! Anyone tried it > > >yet??? > > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: S-T Morrissey Subject: hinge effects Date: Sat, 6 Mar 1999 20:40:46 -0600 (CST) Brett, Thanks for your recent note about modeling the mechanical period of the vertical leaf-spring configuration and the formula for calculating the restoring force effect of the flat leaf orthogonal hinges. It has brought out an important point about the flat-leaf hinge assembly on the STM that is missing from the drawing, namely the "free air" length of the hinges. (I did post a note about it last Nov 24) When I prepare the aluminum angle brackets that the hinges are epoxied to, I file off the outside corners of the angles in the area where the hinges go from one bracket to the other. I file the corner at a 45deg angle, removing about 1/16 or more from each orthogonal side, so when the hinges are assembled, the free air distance is at least 0.125 inches. The actual pivot point is within the hinge thickness (0.005") of the corner of the angles. This free air length results in about 1/3 the force you estimated for 0.040", but it is still significant. This method of providing the hinge clearance has been common practice in many of the hinge designs I have seen in large mechanical seismometers over the years. But now you have provided the reason that it is important, especially when thicker spring material is used to provide a strong assembly. And clearly, if, for example, 0.003" material is used, the force would be about 1/5 of that of the 0.005", but would probably still be strong enough. I used the 0.005" bronze strap because I have about 50 lbs of it. But this relatively significant force does complicate the task of modeling the behavior of the vertical seismometer as the leaf spring is adjusted for minimal restoring force and long periods. In the case of the horizontal, it means that when the boom is exactly horizontal with respect to gravity, the mechanical period resulting from the hinge force will prevail, and as the boom is further raised at the mass end, a small component of g will be cancelling the hinge force, up to the point of instability and infinite period. From this we can see why period instability (and thermal effects) gets to be a serious problem when the actual hinge geometry (center of flexure) changes very slightly with the angle of the boom when the hinges themselves are exerting a significant restoring force. For the vertical configuration, the force of the spring has to offset the force of the hinge stiffness to realize longer periods. This was largely ignored in seismometer designs, which assumed that the hinges exerted zero force compared to the support spring. In the old literature on long period vertical sensors, this was interpreted as configuring the "zero-length" spring for a numerically positive effective length, slightly longer than the number considered as "zero length". I am adding updates to the drawing of the seis, and I will add an inset showing this detail of the hinge assembly. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Bonnie Schafer" Subject: Re: Fw: {EarthWaves} "CYBERSYSTEM" FOR EARTHQUAKE ENGINEERING SIMULATION Date: Sat, 6 Mar 1999 20:51:21 -0800 Hi Edward, Actually, I never thought of that but now that you have brought it to my attention it makes perfect sense. Thanks Bonnie the crafty crafter _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Re: WinQuake beta releases Date: Sun, 07 Mar 1999 08:29:11 -0400 Edward Don't you worry - my confusion won't last forever. Wayne _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: Web-page error Date: Sun, 07 Mar 1999 08:34:36 -0400 Hello all For those of you who regularly visit the new Dominica Public Seismic Network website regularly, you may have noticed that something has gone wrong with the data in there. This is because yesterday, Saturday, the people who host the site upgraded their system. They have replaced all my recent files with older (probably backup) copies. So far I have been unable to update them. Hopefully they will get their act together soon so that I can update them again. http://www.freeyellow.com/members6/dominicapsn/ Wayne. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: robert barns <75612.2635@..............> Subject: Re: WinQuake beta releases Date: Sun, 7 Mar 1999 14:06:08 -0500 About 2 years ago, I posted plans for a calibrator for a horizontal seismometer. You can see this at psn.quake.net/calibrate.html Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Charlie Rond Subject: Re: EMON 7.3a beta version available Date: Sun, 07 Mar 1999 14:39:47 -0600 Ted, >A new version of EMON is available for any intrepid beta testers >willing to give it a try. Here are the new features: I'm anxious to give it a try here! Let us know the next step. Keep up the good work.. Charlie Rond -\/\--Public Seismic Network-Memphis http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Edward Cranswick Subject: Re: WinQuake beta releases Date: Sun, 07 Mar 1999 14:52:25 -0700 Wayne- Where do I get copies of the recents, such as, "18:16 UTC March 02, 1999 [largest quake of the day and aftershock. Was felt over a wide area]"? -Edward Wayne Abraham J73WA wrote: > Edward > > Don't you worry - my confusion won't last forever. > > Wayne > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Malcolm Purves Subject: Re: WinQuake beta releases Date: Sun, 07 Mar 1999 23:09:15 +0000 Excellent exposition Ed. I liked that, I think I am not too confused:-) Back in my youth I was familiar with dx/dy etc for the progression from displacement to velocity to accel. But I had previously, fuzzily, thought that the integral of the displacement might be related to the energy and the Richter Mag., of the quake. But I never got round to thinking about it in detail. Thanks, Malcolm. Edward Cranswick wrote: > > Barry- > Well, integrating or any other kind of analytic math has always been alot of work > for me to understand, so forgetting about the niceties of calculus for a second, I will > give the cartoon version of the ground motion story. This presentation will be in terms etc,snip. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Francesco" Subject: I.E.S.N EQ MESSAGE NOTIFICATION Date: Tue, 9 Mar 1999 16:50:40 +0100 DATE H LAT LONG LOCALIZ = M -------------------------------------------------------------------------= ------------------ 990308 12:25:45 52.13N 159.32E EST OF KAMTCHATKA 6.8 MS This is a preliminary information based on the recorder of all I.ES.N. = italian stations, subject to verification and correction
DATE       =20 H            =        =20 LAT        =20 LONG       =20 LOCALIZ        M
----------------------------------------------------------------= ---------------------------
 
990308  = 12:25:45   =20 52.13N  159.32E     EST OF=20 KAMTCHATKA     6.8 MS
 
 
This is a preliminary information = based on the=20 recorder of all I.ES.N. italian stations, subject to verification and=20 correction
From: "Mark Robinson" Subject: Something fairly large just happened Date: Tue, 9 Mar 1999 04:52:34 +1300 look to the machines lads and ladettes Mark G Robinson | ZL2TOD | other@............... Box 8770, Auckland 1035, New Zealand Phone +64-9-846-3296 | Fax +64-9-849-7408 ------------------------------------------------ 09 Mar 1562 Kissing in public becomes punishable by death in Naples. 09 Mar 1929 A magnitude 6.9 earthquake centred at Arthurs Pass is felt = from Auckland to Bluff. 09 Mar 1956 Opo the dolphin found dead at Opononi. 09 Mar 1997 Lulu Ellen Caitcheon born.
look to the = machines lads and=20 ladettes
 
 
Mark G Robinson = | ZL2TOD | other@...............
Box=20 8770,       Auckland=20 1035,       New Zealand
Phone=20 +64-9-846-3296    |     Fax=20 +64-9-849-7408
------------------------------------------------
09 = Mar=20 1562 Kissing in public becomes punishable by death in Naples.
09 Mar = 1929 A=20 magnitude 6.9 earthquake centred at Arthurs Pass is felt=20 from
           = ;=20 Auckland to Bluff.
09 Mar 1956 Opo the dolphin found dead at = Opononi.
09=20 Mar 1997 Lulu Ellen Caitcheon born.
From: repnizza Subject: Re: QUAKE IN PROGRESS Date: Mon, 08 Mar 1999 14:19:45 +0100 in Piedmont Region (Italy) P & S saturation: Time of arrival: 12.38 UTC Localization: Kamchatka or nearbies ??? Roberto Pozzo Liberio Rossi ha scritto: > >From LAT 43.922 LONG. 10.532E quake in progress. > org. 12.34.6 UTC. > Saluti Liberio rossi LUCCA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Ted Blank Subject: Re: EMON 7.3a beta version available Date: Mon, 8 Mar 1999 09:32:27 -0800 (PST) Norman, I have sent you and four others e-mail with the new code attached. Thanks, look forward to your comments. Ted Blank San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Liberio Rossi" Subject: QUAKE IN PROGRESS Date: Mon, 8 Mar 1999 14:03:32 +0100 From LAT 43.922 LONG. 10.532E quake in progress. org. 12.34.6 UTC. Saluti Liberio rossi LUCCA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Wayne Abraham J73WA Subject: DPSN Website back in order Date: Mon, 08 Mar 1999 19:55:18 -0400 Hello all Just to inform you all that the Dominica Public Seismic Network website http://www.freeyellow.com/members6/dominicapsn/ is in order again. I have reloaded all my files and updated the site with the larger quakes from the swarm of March 02, 1999. Wayne _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Norman Davis WB6SHI Subject: Re: EMON 7.3a beta version available Date: Mon, 08 Mar 1999 20:04:27 -0800 Thanks. Am still trying to find a cheap a/d card. At 09:32 AM 3/8/99 -0800, you wrote: >Norman, I have sent you and four others e-mail with the new code >attached. Thanks, look forward to your comments. > > >Ted Blank >San Jose, California > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L > > Norman M. Davis WB6SHI Shingle springs, CA Email: normd@............. http://www.directcon.net/normd/index.htm ICQ: 7192318 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Ted Blank Subject: Re: EMON 7.3a beta version available Date: Mon, 8 Mar 1999 20:48:54 -0800 (PST) Cheapest one I know of (good quality) is ComputerBoards Inc. 12-bit 8 channel for $149. It is on their web page, www.computerboards.com as I recall. Anyone know where to get this one cheaper? Model is CIO-DAS/08. Ted Blank San Jose, California On Mon, 8 Mar 1999, Norman Davis WB6SHI wrote: > Thanks. Am still trying to find a cheap a/d card. > > At 09:32 AM 3/8/99 -0800, you wrote: > >Norman, I have sent you and four others e-mail with the new code > >attached. Thanks, look forward to your comments. > > > > > >Ted Blank > >San Jose, California > > > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@.............. with the body of the > >message: leave PSN-L > > > > > Norman M. Davis WB6SHI Shingle springs, CA > Email: normd@............. > http://www.directcon.net/normd/index.htm > ICQ: 7192318 > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Re: EMON 7.3a beta version available Date: Mon, 08 Mar 1999 21:08:32 -0800 All, Sorry for the blatant plug but my 12 bit A/D card is only $30.00 more and the small profit I make helps pay for the cost to run this list....You also get a registered copy of my WinQuake program, a $30.00 value as they say. The current version of Emon will work with my board (thanks Ted!) or you can use my SDR program. With the $15.00 WWV option, and a dedicated short-wave receiver, you can have accurate event file timing if you use SDR. Regards, Larry Cochrane Redwood City, PSN At 08:48 PM 3/8/99 -0800, you wrote: > >Cheapest one I know of (good quality) is ComputerBoards Inc. 12-bit 8 >channel for $149. It is on their web page, www.computerboards.com as I >recall. Anyone know where to get this one cheaper? Model is CIO-DAS/08. > > >Ted Blank >San Jose, California > >On Mon, 8 Mar 1999, Norman Davis WB6SHI wrote: > >> Thanks. Am still trying to find a cheap a/d card. >> >> At 09:32 AM 3/8/99 -0800, you wrote: >> >Norman, I have sent you and four others e-mail with the new code >> >attached. Thanks, look forward to your comments. >> > >> > >> >Ted Blank >> >San Jose, California > >> Norman M. Davis WB6SHI Shingle springs, CA >> Email: normd@............. >> http://www.directcon.net/normd/index.htm >> ICQ: 7192318 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Larry Cochrane Subject: Calibrating my Lehman using integration... Date: Tue, 09 Mar 1999 01:41:31 -0800 Hi Everyone, I have some questions for the experts on how to calibrate my Lehman using the FBA-23 accelerometer I am monitoring. First some background; On 2/04/99 at 0:19:36 UTC we had an interesting local double event. The first event was ~ML 3.8 and the second event was somewhat smaller. The events where about 72km from my house. I recorded both events on scale with my Lehman, peek count = 32100 out of 32768, and the FBA-23 recorded a peek count of 43. The files I am using for the information below can be downloaded from my system. The event files are 990204a.lc1, my N-S Lehman, and 990204a.lc5 the N-S channel of the FBA-23. The two sensors are located right next to each other in a spare bedroom. Since I know the characteristics (sensitivity) of FBA sensor, in fact it just got calibration at Kinemetrics a few days before the event!, I should be able to use it to calibrate my Lehman. The problem is the FBA outputs acceleration and my Lehman outputs velocity. Using WinQuake's integration feature, I should be able to convert the FBA data to velocity, by integrating once, and use this to come up with the sensitivity of my Lehman. The FBA channel has the following sensitivity; Full scale is +- 2g, this gives a min/max A/D count of 32768 (16 bit A/D system) so each A/D count is 61.03 ug ( 65536 counts / 4 g). The event produced a peek count of 43, so the peek acceleration was around 2.62 mg (61.03 ug * 43). After integrating the FBA event file, I get a peek count of 1.39 (Note: you will need to use the newest WinQuake beta release to see numbers below 1 after integration). After doing the integration, the event file looks very similar to my Lehman around the S wave, except for the 32100 to 1.39 count difference. Since there is a 32100 to 1.39 difference, I think I can say that my Lehman is ~23,093 times more sensitive then the FBA sensor, after converting to velocity. That would make sense, since the FBA is a strong motion sensor and my Lehman is a higher gain device. So my question basically gets down to what is the 1.39 number I get after doing the integration and can I say that my Lehman has a gain of 23K that number, more or less? Since the FBA senors is a little out of the background noise of the my system (about +- 5 counts or +- .3 mg) there is some error in the 2.62 mg and 1.39 numbers. Part of the 23k gain difference is the amplification between the pickup coil on the Lehman and the A/D converter. I think the gain of my amp / filter card is set too ~5K. If the gain is 5K, then the coil / magnet combination is only around 4.6 times more sensitive then the FBA, after integrating etc.... What I would like to do is measure the actual sensitivity of the coil and magnet, some how, and compare it to the calculated number using the FBA / WinQuake integration method. I think it would be interesting too try and "close the loop" and calibrate my Lehman using the two methods and see how close I can get. One more thing, it has to do with the damping of my Lehman. I think it is safe to say that the actual amount of damping of my Lehman has little effect on my results. My Lehman currently has a natural period of around 8 seconds (If I set it any longer I constantly have to adjust the #$%&^ thing). As I understand it, damping effects the response around the natural period of the pendulum, more of less.... Since the period of the wave used for the peek measurements information above are around 3 to 5 hz, well above the 8 sec period of my Lehman, a little under or over damped system should not effect things too much. Is this a correct statement? Thanks for any input... Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Calibrating my Lehman using integration... Date: Tue, 09 Mar 1999 08:19:13 -0700 (MST) On Tue, 9 Mar 1999, Larry Cochrane wrote: > Since I know the characteristics (sensitivity) of FBA sensor, in fact it > just got calibration at Kinemetrics a few days before the event!, I should > be able to use it to calibrate my Lehman. The problem is the FBA outputs > acceleration and my Lehman outputs velocity. Using WinQuake's integration > feature, I should be able to convert the FBA data to velocity, by > integrating once, and use this to come up with the sensitivity of my Lehman. Larry, The only problem is that each device will have a different frequency response. This means that the FBA sensor may show its maximum amplitude for a certain frequency component of the signal, and that frequency will have a different amplification for the Lehman, and will probably not be the maximum amplitude frequency for the Lehman record. I suppose the best way to determine the differences in amplitude response is to integrate your FBA sensor's record, then do an FFT. Compare this FFT with the FFT for the Lehman sensor; these should be different in a way that reflects each instrument's response. If the FFTs are very similar, then you can certainly make a correlation between the FBA and the Lehman that will not be too far from its real value. But because Lehmans are lower frequency instruments I don't know that this will be the case. Perhaps the best thing to do is make a narrow bandpass filter for each record over the same narrow frequency range (some where between the natural frequency for the FBA and the Lehman where the signal is strong). Then do an IFFT in order to find the maximum counts and use these for your calibration. Another complicated method would involve subtracting one FFT from the other, which I won't say much about since it is probably unnecessary and also beyond the capabilities of Winquake (but this would be a cool feature!)... ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: robert barns <75612.2635@..............> Subject: my web site Date: Tue, 9 Mar 1999 11:19:04 -0500 Hi gang, what's shakin'? I got my website working yesterday. It has some pics of seismometers a= nd a lot of other stuff. www.webspan.net/~bbarns Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Karl Cunningham Subject: Re: Calibrating my Lehman using integration... Date: Tue, 09 Mar 1999 08:40:06 -0800 Hi Larry -- Adding a couple of cents to what John said... As John said, it is important that the records you are comparing have similar bandwidths. If you can be certain that there is a frequency range of flat response from both (understanding that one is velocity and the other is acceleration), you can use WinQuake to do the same bandpass filtering to both, then integrate the acceleration to velocity and compare the waveforms. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Calibrating my Lehman using integration... Date: Tue, 09 Mar 1999 11:44:02 -0700 (MST) On Tue, 9 Mar 1999, Karl Cunningham wrote: > Hi Larry -- > Adding a couple of cents to what John said... > As John said, it is important that the records you are comparing have > similar bandwidths. If you can be certain that there is a frequency range > of flat response from both (understanding that one is velocity and the > other is acceleration), you can use WinQuake to do the same bandpass > filtering to both, then integrate the acceleration to velocity and compare > the waveforms. Karl, Wouldn't you want to integrate the acceleration record first, and then apply the bandpass to it? That way you are working in a velocity spectrum for both records... ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Ted Blank Subject: Re: EMON 7.3a beta version available Date: Tue, 9 Mar 1999 12:31:22 -0800 (PST) Yes, by all means keep your money circulating within the PSN! Hmmm, maybe I'll contact some of these A/D board companies and ask them if they will make a donation to the PSN for every board a member buys. Couldn't hurt to ask...kind of like Points for COmputers at our local mall. Ted Blank San Jose, California On Mon, 8 Mar 1999, Larry Cochrane wrote: > All, > > Sorry for the blatant plug but my 12 bit A/D card is only $30.00 more and > the small profit I make helps pay for the cost to run this list....You also > get a registered copy of my WinQuake program, a $30.00 value as they say. > > The current version of Emon will work with my board (thanks Ted!) or you > can use my SDR program. With the $15.00 WWV option, and a dedicated > short-wave receiver, you can have accurate event file timing if you use SDR. > > Regards, > > Larry Cochrane > Redwood City, PSN > > > At 08:48 PM 3/8/99 -0800, you wrote: > > > >Cheapest one I know of (good quality) is ComputerBoards Inc. 12-bit 8 > >channel for $149. It is on their web page, www.computerboards.com as I > >recall. Anyone know where to get this one cheaper? Model is CIO-DAS/08. > > > > > >Ted Blank > >San Jose, California > > > >On Mon, 8 Mar 1999, Norman Davis WB6SHI wrote: > > > >> Thanks. Am still trying to find a cheap a/d card. > >> > >> At 09:32 AM 3/8/99 -0800, you wrote: > >> >Norman, I have sent you and four others e-mail with the new code > >> >attached. Thanks, look forward to your comments. > >> > > >> > > >> >Ted Blank > >> >San Jose, California > > > >> Norman M. Davis WB6SHI Shingle springs, CA > >> Email: normd@............. > >> http://www.directcon.net/normd/index.htm > >> ICQ: 7192318 > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Karl Cunningham Subject: Re: Calibrating my Lehman using integration... Date: Tue, 09 Mar 1999 13:14:53 -0800 John -- Absolutely right! Otherwise the integrator would not have the full spectrum to work with. Thanks for pointing that out. Another thing I forgot to mention is that it is important that both sensors have a significant amount of flat bandwidth that overlaps, or they'll never agree. -- Karl At 11:44 AM 3/9/99 -0700, you wrote: >Karl, > Wouldn't you want to integrate the acceleration record first, and then >apply the bandpass to it? That way you are working in a velocity spectrum for >both records... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: Hinges and things Date: Tue, 09 Mar 1999 20:10:35 -0500 Seismo builders, Recently, I was looking at calculating the restoring force on a crossed-spring hinge. That got me wondering what it would take to modify the design to have even lower resistance. I think I've stumbled on a configuration that appears to have zero restoring force. I wonder if it will work in practice? see: zerohnge.pdf Also, the file I recently put up regarding the geometry of a leaf spring vertical has now been put into ".pdf" form. Was previously having trouble getting the drawings to look right when I made the .pdf. vertgeom.pdf available for downloading at: http://members.home.net/nordgren/public/ Brett Nordgren _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: GeE777@....... Subject: Rotating Horizontal Seismic Data Date: Tue, 9 Mar 1999 20:40:57 EST Hello All, I am now able to record earthquake data from a three component 10 HZ geophone. The geophone elements are one vertical and the two horizontal, east-west and north-south. I would like to process the horizontal recorded seismic events and determine the direction and relative amplitude of the shear wave. Does anyone know of an application, preferably a windows program that can do this? The data can be in two spreadsheet columns or the like. I only expect to record near by events with this system. I am using Vernier Software's MultiPurpose Lab Interface hardware and software to input the three channels into my computer. Anyone who wants to know more about this recording method e-mail dvernier@........... George Erich Seismic Exploration Consultant P. O. Box 2011, Norwalk, CA 90651, U. S. A. Phone (562) 868-6013 e-mail GeE777@....... 33 53.90N 118 04.53W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Angel Rodriguez Subject: Re: Rotating Horizontal Seismic Data Date: Tue, 9 Mar 1999 21:16:02 -0500 Hi, I have been trying a program call Seisan the may be able to do that. I will be using it to locate local evenst from my 3 componemt 8hz device that I hope to have next wedk. I know that I will be able to get the azimuth of the event. It runs in dos, w95 and on my w98. You can get the manual in PDF format at my ftp ftp://ftp.barriles.com/sismos be forwarned that my ftp is slow becasue it=B4s at the end of a verly long string of routers in Panama. I also have a program that will convert from PSN format to seisan format Seisan does a bunch of stuff Warmly angel _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: barry lotz Subject: Displacement calibration Date: Tue, 09 Mar 1999 20:24:21 -0800 While we are on calibration, I thought I'd mention a new find for me, though it may not be new to others. I was trying to calibrate a homemade LVDT for the high gains STM uses in the VBB sensor. I have only a micrometer with a resolution of 0.001". However I have a weigh scale that reads to 0.1gms. So what I did was calibrate the LVDT for a lower gain with the micrometer so ~3vts=0.020". Then I constructed a 12" long cantilivered beam of 0.125" X 1.00" section. I connected the LVDT at the end of the beam (axis vertical). Normally the deflection of a cant. beam w/concentrated end load would be PL^3/(3EI). Because I couldn't trust my section and length measurements, decided to determine L^3/(3EI). Regardless of gain this should be constant. I used the low gain setting with weights from 0.6 to 20gms. and obtained a factor("/gm). then I increased the LVDT gain ~20 times and applied the lower valued weights (0.2-2.0gms) and got a gain of ~3000vts/in with minimal difficulty. I think with a slightly thicker cantiliver or shorter length I could increase the gain higher yet, since the deflection would be lower. As a note ,I took a zero reading then loaded the beam then took a new zero reading to determine the deflection. There was long term drifting probably due to thermal gradients on the steel cantilever. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: "Charles R. Patton" Subject: Re: Hinges and things Date: Tue, 09 Mar 1999 22:07:56 -0800 Brett Nordgren wrote: > I think I've stumbled on a > configuration that appears to have zero restoring force. I wonder if i= t > will work in practice? > > see: zerohnge.pdf Brett, The first Rolamite patents started about 1972 by Dean E. Gladow and were assigned to Rolamite Inc. in San Francisco, CA. Representative patent num= bers are 3710631, 3691871. As I recall Dean worked for a govt. lab, so the Rol= amite corp licensed the patents to commercially develop them. One later patent= by someone else is 4438983. I have played with these bearings and they have incredibly low friction and hysteresis, even in large sizes. One variati= on I came up with solves one big problem which is that in the previous forms t= he bearings require the use of pressure to keep the cylinders together =96 t= he minute they go into tension, they separate and the performance (geometry)= of the pivot is uncertain. The method to do this is quite simple. Imagine = a stepped cylinder where the top and bottom are a given diameter and the ce= nter section is about 1/2 (not critical) that diameter. Take two of these cylinders and wrap the bands as you would previously. Now the tension in= the center band has two right angle vector components, one acting to keep the bearing together, and the other to keep the bands in tension. This beari= ng is very well behaved. This bearing can be easily constructed with drill ro= d and drill bushings and SS or brass shim stock. to have excellent performance. Charles R. Patton _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Rotating Horizontal Seismic Data Date: Wed, 10 Mar 1999 11:05:16 -0700 (MST) On Tue, 9 Mar 1999 GeE777@....... wrote: > I am now able to record earthquake data from a three component 10 HZ geophone. > The geophone elements are one vertical and the two horizontal, east-west and > north-south. I would like to process the horizontal recorded seismic events > and determine the direction and relative amplitude of the shear wave. Does > anyone know of an application, preferably a windows program that can do this? > The data can be in two spreadsheet columns or the like. I only expect to > record near by events with this system. > I am using Vernier Software's MultiPurpose Lab Interface hardware and > software to input the three channels into my computer. Anyone who wants to > know more about this recording method e-mail dvernier@........... > George Erich George, I have written many fortran codes for doing this type of thing. You will need to save the data in ASCII format. The way to do this is very simple, you just use rotation matrices for the vector components of motion. Doing this, you can rotate your data into an reference frame. It is best to look at the data in several ways: - Rotate it to the back azimuth to source direction and the vary the sideways tile angle. - Rotate the horizontal components all around 360 degrees. People do this to try and find anisotropy... As far as getting this into windows... You could load the data into excel or something like that and accomplish the same thing if you have a very fast computer... I would try this first before getting too fancy. ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Brett Nordgren Subject: More geometry Date: Thu, 11 Mar 1999 09:37:05 -0500 To all: The file "vertgeom.pdf" has been updated today to include some new graphs. These show the results from adjusting the dimensions of a leaf spring vertical to achieve zero net restoring force. Located at: http://members.home.net/nordgren/public/ Brett Nordgren bnordgren@.............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Dick Webb Subject: Reading Seismograms Date: Fri, 12 Mar 1999 08:14:20 -0500 For the past few years, I've been using "Earthquake Interpretations A manual for Reading Seismograms" by Simon as an aid in reading seismograms. I've not been able to locate other guides. Do you know of any books or references that give good guidance on making the proper picks. Particularly teleseisms. Dick _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Reading Seismograms Date: Fri, 12 Mar 1999 10:42:10 -0700 (MST) On Fri, 12 Mar 1999, Dick Webb wrote: > For the past few years, I've been using "Earthquake Interpretations A > manual for Reading Seismograms" by Simon as an aid in reading seismograms. > I've not been able to locate other guides. Do you know of any books or > references that give good guidance on making the proper picks. > Particularly teleseisms. Dick, I think most people do things similar to Larry's arrival time picks by plugging in an epicentral distance, depth, and a reference earth model. The reference earth model is itself an inversion of arrival times averaged for many events. If you wanted to get really fancy, you can also have programs that will include the station elevation as well (This effect is less than 1 second, but in some areas this can be important). Different customs exist in earth science like which reference model is used. There are currently three models in use: PREM (Preliminary Reference Earth Model), IASPEI91 (Int'l Assoc. Seis. Phys. Earth. 1991), and the older J-B (Jeffreys-Bullen). Most people use PREM it seems, but which model you use can affect the timing of arrivals. For example, some models put a discontinuity at around 200 km depth, and others don't. This discontinuity may reflect deep continental roots under older cratons. Anyways, the two former models are given roughly below. It is interesting to plot one against the other using one of the parameters to see how the two models give different interpretations. In the following, it may be obvious, but I might as well state it: depth= distance from surface density=mass/unit volume vp= P-wave velocity vs= S-wave velocity Qp= Q factor for P-waves (attenuation) Qs= Q factor for S-waves (attenuation) This is the IASPEI91 model: depth density vp vs Qp Qs Junk 0.00 2.72000 5.80000 3.36000 1456.00 600.00 0.00000 20.00 2.72000 5.80000 3.36000 1350.00 600.00 0.00000 20.00 2.92000 6.50000 3.75000 1350.00 600.00 0.00000 35.00 2.92000 6.50000 3.75000 1350.00 600.00 0.00000 35.00 3.31980 8.04000 4.47000 1350.00 600.00 0.00000 77.50 3.34550 8.04500 4.48500 195.00 80.00 0.00000 120.00 3.37130 8.05000 4.50000 195.00 80.00 0.00000 165.00 3.39850 8.17500 4.50900 195.00 80.00 0.00000 210.00 3.42580 8.30000 4.51800 362.00 143.00 0.00000 210.00 3.42580 8.30000 4.52200 362.00 143.00 0.00000 260.00 3.45610 8.48250 4.60900 365.00 143.00 0.00000 310.00 3.48640 8.66500 4.69600 367.00 143.00 0.00000 360.00 3.51670 8.84750 4.78300 372.00 143.00 0.00000 410.00 3.54700 9.03000 4.87000 365.00 143.00 0.00000 410.00 3.75570 9.36000 5.07000 365.00 143.00 0.00000 460.00 3.81750 9.52800 5.17600 364.00 143.00 0.00000 510.00 3.87930 9.69600 5.28200 363.00 143.00 0.00000 560.00 3.94100 9.86400 5.38800 362.00 143.00 0.00000 610.00 4.00280 10.03200 5.49400 362.00 143.00 0.00000 660.00 4.06460 10.20000 5.60000 362.00 143.00 0.00000 660.00 4.37140 10.79000 5.95000 759.00 312.00 0.00000 710.00 4.40100 10.92290 6.07970 744.00 312.00 0.00000 760.00 4.43050 11.05580 6.20950 730.00 312.00 0.00000 809.50 4.45960 11.14400 6.24740 737.00 312.00 0.00000 859.00 4.48850 11.23000 6.28410 739.00 312.00 0.00000 908.50 4.51730 11.31400 6.31990 743.00 312.00 0.00000 958.00 4.54590 11.39600 6.35460 745.00 312.00 0.00000 1007.50 4.57440 11.47610 6.38830 750.00 312.00 0.00000 1057.00 4.60280 11.55430 6.42110 752.00 312.00 0.00000 1106.50 4.63100 11.63080 6.45300 755.00 312.00 0.00000 1156.00 4.65910 11.70560 6.48410 757.00 312.00 0.00000 1205.50 4.68700 11.77870 6.51430 761.00 312.00 0.00000 1255.00 4.71480 11.85040 6.54380 763.00 312.00 0.00000 1304.50 4.74240 11.92050 6.57250 766.00 312.00 0.00000 1354.00 4.76990 11.98930 6.60060 768.00 312.00 0.00000 1403.50 4.79730 12.05680 6.62800 770.00 312.00 0.00000 1453.00 4.82450 12.12310 6.65470 772.00 312.00 0.00000 1502.50 4.85150 12.18810 6.68090 775.00 312.00 0.00000 1552.00 4.87850 12.25210 6.70660 777.00 312.00 0.00000 1601.50 4.90520 12.31510 6.73170 779.00 312.00 0.00000 1651.00 4.93190 12.37720 6.75640 781.00 312.00 0.00000 1700.50 4.95840 12.43830 6.78070 784.00 312.00 0.00000 1750.00 4.98470 12.49870 6.80460 786.00 312.00 0.00000 1799.50 5.01090 12.55840 6.82820 788.00 312.00 0.00000 1849.00 5.03700 12.61740 6.85140 790.00 312.00 0.00000 1898.50 5.06290 12.67590 6.87450 792.00 312.00 0.00000 1948.00 5.08870 12.73390 6.89720 793.00 312.00 0.00000 1997.50 5.11430 12.79150 6.91990 795.00 312.00 0.00000 2047.00 5.13980 12.84870 6.94230 797.00 312.00 0.00000 2096.50 5.16520 12.90570 6.96470 799.00 312.00 0.00000 2146.00 5.19040 12.96250 6.98700 801.00 312.00 0.00000 2195.50 5.21540 13.01920 7.00930 803.00 312.00 0.00000 2245.00 5.24030 13.07580 7.03160 805.00 312.00 0.00000 2294.50 5.26510 13.13250 7.05400 807.00 312.00 0.00000 2344.00 5.28980 13.18920 7.07650 809.00 312.00 0.00000 2393.50 5.31420 13.24620 7.09910 811.00 312.00 0.00000 2443.00 5.33860 13.30340 7.12180 813.00 312.00 0.00000 2492.50 5.36280 13.36100 7.14490 815.00 312.00 0.00000 2542.00 5.38690 13.41900 7.16810 817.00 312.00 0.00000 2591.50 5.41080 13.47740 7.19170 819.00 312.00 0.00000 2641.00 5.43450 13.53640 7.21560 820.00 312.00 0.00000 2690.50 5.45820 13.59610 7.23980 822.00 312.00 0.00000 2740.00 5.48170 13.65640 7.26450 823.00 312.00 0.00000 2789.67 5.50510 13.66790 7.27680 826.00 312.00 0.00000 2839.33 5.52840 13.67930 7.28920 826.00 312.00 0.00000 2889.00 5.55150 13.69080 7.30150 826.00 312.00 0.00000 2889.00 9.91450 8.00880 0.00000 57882.00 0.00 0.00000 2939.33 9.99420 8.09630 0.00000 57822.00 0.00 0.00000 2989.66 10.07220 8.18210 0.00000 57822.00 0.00 0.00000 3039.99 10.14850 8.26620 0.00000 57822.00 0.00 0.00000 3090.32 10.22330 8.34860 0.00000 57822.00 0.00 0.00000 3140.66 10.29640 8.42930 0.00000 57822.00 0.00 0.00000 3190.99 10.36790 8.50830 0.00000 57822.00 0.00 0.00000 3241.32 10.43780 8.58560 0.00000 57822.00 0.00 0.00000 3291.65 10.50620 8.66110 0.00000 57822.00 0.00 0.00000 3341.98 10.57310 8.73500 0.00000 57822.00 0.00 0.00000 3392.31 10.63850 8.80720 0.00000 57822.00 0.00 0.00000 3442.64 10.70230 8.87760 0.00000 57822.00 0.00 0.00000 3492.97 10.76470 8.94640 0.00000 57822.00 0.00 0.00000 3543.30 10.82570 9.01340 0.00000 57822.00 0.00 0.00000 3593.64 10.88520 9.07870 0.00000 57822.00 0.00 0.00000 3643.97 10.94340 9.14240 0.00000 57822.00 0.00 0.00000 3694.30 11.00010 9.20430 0.00000 57822.00 0.00 0.00000 3744.63 11.05550 9.26450 0.00000 57822.00 0.00 0.00000 3794.96 11.10950 9.32300 0.00000 57822.00 0.00 0.00000 3845.29 11.16230 9.37980 0.00000 57822.00 0.00 0.00000 3895.62 11.21370 9.43490 0.00000 57822.00 0.00 0.00000 3945.95 11.26390 9.48830 0.00000 57822.00 0.00 0.00000 3996.28 11.31270 9.54000 0.00000 57822.00 0.00 0.00000 4046.62 11.36040 9.59000 0.00000 57822.00 0.00 0.00000 4096.95 11.40690 9.63830 0.00000 57822.00 0.00 0.00000 4147.28 11.45210 9.68480 0.00000 57822.00 0.00 0.00000 4197.61 11.49620 9.72970 0.00000 57822.00 0.00 0.00000 4247.94 11.53910 9.77280 0.00000 57822.00 0.00 0.00000 4298.27 11.58090 9.81430 0.00000 57822.00 0.00 0.00000 4348.60 11.62160 9.85400 0.00000 57822.00 0.00 0.00000 4398.93 11.66120 9.89200 0.00000 57822.00 0.00 0.00000 4449.26 11.69980 9.92840 0.00000 57822.00 0.00 0.00000 4499.60 11.73730 9.96300 0.00000 57822.00 0.00 0.00000 4549.93 11.77370 9.99590 0.00000 57822.00 0.00 0.00000 4600.26 11.80920 10.02710 0.00000 57822.00 0.00 0.00000 4650.59 11.84370 10.05660 0.00000 57822.00 0.00 0.00000 4700.92 11.87720 10.08440 0.00000 57822.00 0.00 0.00000 4751.25 11.90980 10.11050 0.00000 57822.00 0.00 0.00000 4801.58 11.94140 10.13490 0.00000 57822.00 0.00 0.00000 4851.91 11.97220 10.15760 0.00000 57822.00 0.00 0.00000 4902.24 12.00210 10.17850 0.00000 57822.00 0.00 0.00000 4952.58 12.03110 10.19780 0.00000 57822.00 0.00 0.00000 5002.91 12.05930 10.21540 0.00000 57822.00 0.00 0.00000 5053.24 12.08670 10.23120 0.00000 57822.00 0.00 0.00000 5103.57 12.11330 10.24540 0.00000 57822.00 0.00 0.00000 5153.90 12.13910 10.25780 0.00000 57882.00 0.00 0.00000 5153.90 12.70370 11.09140 3.43850 445.00 85.00 0.00000 5204.61 12.72890 11.10360 3.44880 444.00 85.00 0.00000 5255.32 12.75300 11.11530 3.45870 443.00 85.00 0.00000 5306.04 12.77600 11.12650 3.46810 441.00 85.00 0.00000 5356.75 12.79800 11.13710 3.47700 440.00 85.00 0.00000 5407.46 12.81880 11.14720 3.48560 439.00 85.00 0.00000 5458.17 12.83870 11.15680 3.49370 438.00 85.00 0.00000 5508.89 12.85740 11.16590 3.50130 437.00 85.00 0.00000 5559.60 12.87510 11.17450 3.50850 436.00 85.00 0.00000 5610.31 12.89170 11.18250 3.51530 436.00 85.00 0.00000 5661.02 12.90720 11.19010 3.52170 435.00 85.00 0.00000 5711.74 12.92170 11.19710 3.52760 434.00 85.00 0.00000 5762.45 12.93510 11.20360 3.53300 434.00 85.00 0.00000 5813.16 12.94740 11.20950 3.53810 433.00 85.00 0.00000 5863.87 12.95860 11.21500 3.54270 433.00 85.00 0.00000 5914.59 12.96880 11.21990 3.54680 432.00 85.00 0.00000 5965.30 12.97790 11.22430 3.55050 432.00 85.00 0.00000 6016.01 12.98590 11.22820 3.55380 432.00 85.00 0.00000 6066.72 12.99290 11.23160 3.55670 432.00 85.00 0.00000 6117.44 12.99880 11.23450 3.55910 431.00 85.00 0.00000 6168.15 13.00360 11.23680 3.56100 431.00 85.00 0.00000 6218.86 13.00740 11.23860 3.56260 431.00 85.00 0.00000 6269.57 13.01000 11.23990 3.56370 431.00 85.00 0.00000 6320.29 13.01170 11.24070 3.56430 0.00 0.00 0.00000 6371.00 13.01220 11.24090 3.56450 0.00 0.00 0.00000 This is the PREM model: 0.00 2.60000 5.80000 3.20000 1456.00 600.00 0.00000 15.00 2.90000 6.80000 3.90000 1350.00 600.00 0.00000 24.40 2.90000 6.80000 3.90000 1350.00 600.00 0.00000 24.40 3.38076 8.11061 4.49094 1446.00 600.00 0.00000 40.00 3.37906 8.10119 4.48486 1446.00 600.00 0.00000 60.00 3.37688 8.08907 4.47715 1447.00 600.00 0.00000 80.00 3.37471 8.07689 4.46954 1447.00 600.00 0.00000 80.00 3.37471 8.07688 4.46953 195.00 80.00 0.00000 115.00 3.37091 8.05540 4.45643 195.00 80.00 0.00000 150.00 3.36710 8.03370 4.44361 195.00 80.00 0.00000 185.00 3.36330 8.01180 4.43108 195.00 80.00 0.00000 220.00 3.35950 7.98970 4.41885 195.00 80.00 0.00000 220.00 3.43578 8.55896 4.64391 362.00 143.00 0.00000 265.00 3.46264 8.64552 4.67540 365.00 143.00 0.00000 310.00 3.48951 8.73209 4.70690 367.00 143.00 0.00000 355.00 3.51639 8.81867 4.73840 370.00 143.00 0.00000 400.00 3.54325 8.90522 4.76989 372.00 143.00 0.00000 400.00 3.72378 9.13397 4.93259 366.00 143.00 0.00000 450.00 3.78678 9.38990 5.07842 365.00 143.00 0.00000 500.00 3.84980 9.64588 5.22428 364.00 143.00 0.00000 550.00 3.91282 9.90185 5.37014 363.00 143.00 0.00000 600.00 3.97584 10.15782 5.51602 362.00 143.00 0.00000 635.00 3.98399 10.21203 5.54311 362.00 143.00 0.00000 670.00 3.99214 10.26662 5.57020 362.00 143.00 0.00000 670.00 4.38071 10.75131 5.94508 759.00 312.00 0.00000 721.00 4.41241 10.91005 6.09418 744.00 312.00 0.00000 771.00 4.44317 11.06557 6.24046 730.00 312.00 0.00000 871.00 4.50372 11.24490 6.31091 737.00 312.00 0.00000 971.00 4.56307 11.41560 6.37813 743.00 312.00 0.00000 1071.00 4.62129 11.57828 6.44232 750.00 312.00 0.00000 1171.00 4.67844 11.73357 6.50370 755.00 312.00 0.00000 1271.00 4.73460 11.88209 6.56250 761.00 312.00 0.00000 1371.00 4.78983 12.02445 6.61891 766.00 312.00 0.00000 1471.00 4.84422 12.16126 6.67317 770.00 312.00 0.00000 1571.00 4.89783 12.29316 6.72548 775.00 312.00 0.00000 1671.00 4.95073 12.42075 6.77606 779.00 312.00 0.00000 1771.00 5.00299 12.54466 6.82512 784.00 312.00 0.00000 1871.00 5.05469 12.66550 6.87289 788.00 312.00 0.00000 1971.00 5.10590 12.78389 6.91957 792.00 312.00 0.00000 2071.00 5.15669 12.90045 6.96538 795.00 312.00 0.00000 2171.00 5.20713 13.01579 7.01053 799.00 312.00 0.00000 2271.00 5.25729 13.13055 7.05525 803.00 312.00 0.00000 2371.00 5.30724 13.24532 7.09974 807.00 312.00 0.00000 2471.00 5.35706 13.36074 7.14423 811.00 312.00 0.00000 2571.00 5.40681 13.47742 7.18892 815.00 312.00 0.00000 2671.00 5.45657 13.59597 7.23403 819.00 312.00 0.00000 2741.00 5.49145 13.68041 7.26597 822.00 312.00 0.00000 2771.00 5.50642 13.68753 7.26575 823.00 312.00 0.00000 2871.00 5.55641 13.71168 7.26486 826.00 312.00 0.00000 2891.00 5.56645 13.71660 7.26466 826.00 312.00 0.00000 2891.00 9.90349 8.06482 0.00000 57882.00 0.00 0.00000 2971.00 10.02940 8.19939 0.00000 57822.00 0.00 0.00000 3071.00 10.18134 8.36019 0.00000 57822.00 0.00 0.00000 3171.00 10.32726 8.51298 0.00000 57822.00 0.00 0.00000 3271.00 10.46727 8.65805 0.00000 57822.00 0.00 0.00000 3371.00 10.60152 8.79573 0.00000 57822.00 0.00 0.00000 3471.00 10.73012 8.92632 0.00000 57822.00 0.00 0.00000 3571.00 10.85321 9.05015 0.00000 57822.00 0.00 0.00000 3671.00 10.97091 9.16752 0.00000 57822.00 0.00 0.00000 3771.00 11.08335 9.27876 0.00000 57822.00 0.00 0.00000 3871.00 11.19067 9.38418 0.00000 57822.00 0.00 0.00000 3971.00 11.29298 9.48409 0.00000 57822.00 0.00 0.00000 4071.00 11.39042 9.57881 0.00000 57822.00 0.00 0.00000 4171.00 11.48311 9.66865 0.00000 57822.00 0.00 0.00000 4271.00 11.57119 9.75393 0.00000 57822.00 0.00 0.00000 4371.00 11.65478 9.83496 0.00000 57822.00 0.00 0.00000 4471.00 11.73401 9.91206 0.00000 57822.00 0.00 0.00000 4571.00 11.80900 9.98554 0.00000 57822.00 0.00 0.00000 4671.00 11.87990 10.05572 0.00000 57822.00 0.00 0.00000 4771.00 11.94682 10.12291 0.00000 57822.00 0.00 0.00000 4871.00 12.00989 10.18743 0.00000 57822.00 0.00 0.00000 4971.00 12.06924 10.24959 0.00000 57822.00 0.00 0.00000 5071.00 12.12500 10.30971 0.00000 57822.00 0.00 0.00000 5149.50 12.16634 10.35568 0.00000 57822.00 0.00 0.00000 5149.50 12.76360 11.02827 3.50432 445.00 85.00 0.00000 5171.00 12.77493 11.03643 3.51002 445.00 85.00 0.00000 5271.00 12.82501 11.07249 3.53522 443.00 85.00 0.00000 5371.00 12.87073 11.10542 3.55823 440.00 85.00 0.00000 5471.00 12.91211 11.13521 3.57905 439.00 85.00 0.00000 5571.00 12.94912 11.16186 3.59767 437.00 85.00 0.00000 5671.00 12.98178 11.18538 3.61411 436.00 85.00 0.00000 5771.00 13.01009 11.20576 3.62835 434.00 85.00 0.00000 5871.00 13.03404 11.22301 3.64041 433.00 85.00 0.00000 5971.00 13.05364 11.23712 3.65027 432.00 85.00 0.00000 6071.00 13.06888 11.24809 3.65794 432.00 85.00 0.00000 6171.00 13.07977 11.25593 3.66342 431.00 85.00 0.00000 6271.00 13.08630 11.26064 3.66670 431.00 85.00 0.00000 The next step to getting an accurate representation of what you see on your seismogram is a method called "synthetic seismograms" which uses a finite-element modelling technique to generate a seismogram based on the information you have given, like the earth model, source mechanism, and any departures from the model between the station and the quake. The earthquake source tells you how the elastic waves looked as they propagated out. There are characteristic radiation patterns for waves leaving an ideal fault (double couple) that are also used. ****************************************************************************** John Hernlund E-mail: hernlund@....... http://www.public.asu.edu/~hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: Dick Webb Subject: Re: Reading Seismograms Date: Fri, 12 Mar 1999 13:30:41 -0500 John, Thanks for the information about earth models. My question is a tad more basic. When confronted with a seismogram what is the best way to approach making picks IF YOU DON'T KNOW THE HYPOCENTER. Are there characteristic shapes and relationships that would let one determine a P from a Pp and even something so simple as an S wave. After all they must have used the eyeball approach before the days of the internet or telemetry. Dick At 10:42 AM 3/12/99 -0700, you wrote: >On Fri, 12 Mar 1999, Dick Webb wrote: >> For the past few years, I've been using "Earthquake Interpretations A >> manual for Reading Seismograms" by Simon as an aid in reading seismograms. >> I've not been able to locate other guides. Do you know of any books or >> references that give good guidance on making the proper picks. >> Particularly teleseisms. > >Dick, > I think most people do things similar to Larry's arrival time picks by >plugging in an epicentral distance, depth, and a reference earth model. The >reference earth model is itself an inversion of arrival times averaged for >many events. If you wanted to get really fancy, you can also have programs >that will include the station elevation as well (This effect is less than 1 >second, but in some areas this can be important). Different customs exist in >earth science like which reference model is used. There are currently three >models in use: PREM (Preliminary Reference Earth Model), IASPEI91 (Int'l >Assoc. Seis. Phys. Earth. 1991), and the older J-B (Jeffreys-Bullen). Most >people use PREM it seems, but which model you use can affect the timing of >arrivals. For example, some models put a discontinuity at around 200 km >depth, and others don't. This discontinuity may reflect deep continental >roots under older cratons. Anyways, the two former models are given roughly >below. It is interesting to plot one against the other using one of the >parameters to see how the two models give different interpretations. In the >following, it may be obvious, but I might as well state it: > >depth= distance from surface >density=mass/unit volume >vp= P-wave velocity >vs= S-wave velocity >Qp= Q factor for P-waves (attenuation) >Qs= Q factor for S-waves (attenuation) > >This is the IASPEI91 model: > > depth density vp vs Qp Qs Junk > 0.00 2.72000 5.80000 3.36000 1456.00 600.00 0.00000 > 20.00 2.72000 5.80000 3.36000 1350.00 600.00 0.00000 > 20.00 2.92000 6.50000 3.75000 1350.00 600.00 0.00000 > 35.00 2.92000 6.50000 3.75000 1350.00 600.00 0.00000 > 35.00 3.31980 8.04000 4.47000 1350.00 600.00 0.00000 > 77.50 3.34550 8.04500 4.48500 195.00 80.00 0.00000 > 120.00 3.37130 8.05000 4.50000 195.00 80.00 0.00000 > 165.00 3.39850 8.17500 4.50900 195.00 80.00 0.00000 > 210.00 3.42580 8.30000 4.51800 362.00 143.00 0.00000 > 210.00 3.42580 8.30000 4.52200 362.00 143.00 0.00000 > 260.00 3.45610 8.48250 4.60900 365.00 143.00 0.00000 > 310.00 3.48640 8.66500 4.69600 367.00 143.00 0.00000 > 360.00 3.51670 8.84750 4.78300 372.00 143.00 0.00000 > 410.00 3.54700 9.03000 4.87000 365.00 143.00 0.00000 > 410.00 3.75570 9.36000 5.07000 365.00 143.00 0.00000 > 460.00 3.81750 9.52800 5.17600 364.00 143.00 0.00000 > 510.00 3.87930 9.69600 5.28200 363.00 143.00 0.00000 > 560.00 3.94100 9.86400 5.38800 362.00 143.00 0.00000 > 610.00 4.00280 10.03200 5.49400 362.00 143.00 0.00000 > 660.00 4.06460 10.20000 5.60000 362.00 143.00 0.00000 > 660.00 4.37140 10.79000 5.95000 759.00 312.00 0.00000 > 710.00 4.40100 10.92290 6.07970 744.00 312.00 0.00000 > 760.00 4.43050 11.05580 6.20950 730.00 312.00 0.00000 > 809.50 4.45960 11.14400 6.24740 737.00 312.00 0.00000 > 859.00 4.48850 11.23000 6.28410 739.00 312.00 0.00000 > 908.50 4.51730 11.31400 6.31990 743.00 312.00 0.00000 > 958.00 4.54590 11.39600 6.35460 745.00 312.00 0.00000 > 1007.50 4.57440 11.47610 6.38830 750.00 312.00 0.00000 > 1057.00 4.60280 11.55430 6.42110 752.00 312.00 0.00000 > 1106.50 4.63100 11.63080 6.45300 755.00 312.00 0.00000 > 1156.00 4.65910 11.70560 6.48410 757.00 312.00 0.00000 > 1205.50 4.68700 11.77870 6.51430 761.00 312.00 0.00000 > 1255.00 4.71480 11.85040 6.54380 763.00 312.00 0.00000 > 1304.50 4.74240 11.92050 6.57250 766.00 312.00 0.00000 > 1354.00 4.76990 11.98930 6.60060 768.00 312.00 0.00000 > 1403.50 4.79730 12.05680 6.62800 770.00 312.00 0.00000 > 1453.00 4.82450 12.12310 6.65470 772.00 312.00 0.00000 > 1502.50 4.85150 12.18810 6.68090 775.00 312.00 0.00000 > 1552.00 4.87850 12.25210 6.70660 777.00 312.00 0.00000 > 1601.50 4.90520 12.31510 6.73170 779.00 312.00 0.00000 > 1651.00 4.93190 12.37720 6.75640 781.00 312.00 0.00000 > 1700.50 4.95840 12.43830 6.78070 784.00 312.00 0.00000 > 1750.00 4.98470 12.49870 6.80460 786.00 312.00 0.00000 > 1799.50 5.01090 12.55840 6.82820 788.00 312.00 0.00000 > 1849.00 5.03700 12.61740 6.85140 790.00 312.00 0.00000 > 1898.50 5.06290 12.67590 6.87450 792.00 312.00 0.00000 > 1948.00 5.08870 12.73390 6.89720 793.00 312.00 0.00000 > 1997.50 5.11430 12.79150 6.91990 795.00 312.00 0.00000 > 2047.00 5.13980 12.84870 6.94230 797.00 312.00 0.00000 > 2096.50 5.16520 12.90570 6.96470 799.00 312.00 0.00000 > 2146.00 5.19040 12.96250 6.98700 801.00 312.00 0.00000 > 2195.50 5.21540 13.01920 7.00930 803.00 312.00 0.00000 > 2245.00 5.24030 13.07580 7.03160 805.00 312.00 0.00000 > 2294.50 5.26510 13.13250 7.05400 807.00 312.00 0.00000 > 2344.00 5.28980 13.18920 7.07650 809.00 312.00 0.00000 > 2393.50 5.31420 13.24620 7.09910 811.00 312.00 0.00000 > 2443.00 5.33860 13.30340 7.12180 813.00 312.00 0.00000 > 2492.50 5.36280 13.36100 7.14490 815.00 312.00 0.00000 > 2542.00 5.38690 13.41900 7.16810 817.00 312.00 0.00000 > 2591.50 5.41080 13.47740 7.19170 819.00 312.00 0.00000 > 2641.00 5.43450 13.53640 7.21560 820.00 312.00 0.00000 > 2690.50 5.45820 13.59610 7.23980 822.00 312.00 0.00000 > 2740.00 5.48170 13.65640 7.26450 823.00 312.00 0.00000 > 2789.67 5.50510 13.66790 7.27680 826.00 312.00 0.00000 > 2839.33 5.52840 13.67930 7.28920 826.00 312.00 0.00000 > 2889.00 5.55150 13.69080 7.30150 826.00 312.00 0.00000 > 2889.00 9.91450 8.00880 0.00000 57882.00 0.00 0.00000 > 2939.33 9.99420 8.09630 0.00000 57822.00 0.00 0.00000 > 2989.66 10.07220 8.18210 0.00000 57822.00 0.00 0.00000 > 3039.99 10.14850 8.26620 0.00000 57822.00 0.00 0.00000 > 3090.32 10.22330 8.34860 0.00000 57822.00 0.00 0.00000 > 3140.66 10.29640 8.42930 0.00000 57822.00 0.00 0.00000 > 3190.99 10.36790 8.50830 0.00000 57822.00 0.00 0.00000 > 3241.32 10.43780 8.58560 0.00000 57822.00 0.00 0.00000 > 3291.65 10.50620 8.66110 0.00000 57822.00 0.00 0.00000 > 3341.98 10.57310 8.73500 0.00000 57822.00 0.00 0.00000 > 3392.31 10.63850 8.80720 0.00000 57822.00 0.00 0.00000 > 3442.64 10.70230 8.87760 0.00000 57822.00 0.00 0.00000 > 3492.97 10.76470 8.94640 0.00000 57822.00 0.00 0.00000 > 3543.30 10.82570 9.01340 0.00000 57822.00 0.00 0.00000 > 3593.64 10.88520 9.07870 0.00000 57822.00 0.00 0.00000 > 3643.97 10.94340 9.14240 0.00000 57822.00 0.00 0.00000 > 3694.30 11.00010 9.20430 0.00000 57822.00 0.00 0.00000 > 3744.63 11.05550 9.26450 0.00000 57822.00 0.00 0.00000 > 3794.96 11.10950 9.32300 0.00000 57822.00 0.00 0.00000 > 3845.29 11.16230 9.37980 0.00000 57822.00 0.00 0.00000 > 3895.62 11.21370 9.43490 0.00000 57822.00 0.00 0.00000 > 3945.95 11.26390 9.48830 0.00000 57822.00 0.00 0.00000 > 3996.28 11.31270 9.54000 0.00000 57822.00 0.00 0.00000 > 4046.62 11.36040 9.59000 0.00000 57822.00 0.00 0.00000 > 4096.95 11.40690 9.63830 0.00000 57822.00 0.00 0.00000 > 4147.28 11.45210 9.68480 0.00000 57822.00 0.00 0.00000 > 4197.61 11.49620 9.72970 0.00000 57822.00 0.00 0.00000 > 4247.94 11.53910 9.77280 0.00000 57822.00 0.00 0.00000 > 4298.27 11.58090 9.81430 0.00000 57822.00 0.00 0.00000 > 4348.60 11.62160 9.85400 0.00000 57822.00 0.00 0.00000 > 4398.93 11.66120 9.89200 0.00000 57822.00 0.00 0.00000 > 4449.26 11.69980 9.92840 0.00000 57822.00 0.00 0.00000 > 4499.60 11.73730 9.96300 0.00000 57822.00 0.00 0.00000 > 4549.93 11.77370 9.99590 0.00000 57822.00 0.00 0.00000 > 4600.26 11.80920 10.02710 0.00000 57822.00 0.00 0.00000 > 4650.59 11.84370 10.05660 0.00000 57822.00 0.00 0.00000 > 4700.92 11.87720 10.08440 0.00000 57822.00 0.00 0.00000 > 4751.25 11.90980 10.11050 0.00000 57822.00 0.00 0.00000 > 4801.58 11.94140 10.13490 0.00000 57822.00 0.00 0.00000 > 4851.91 11.97220 10.15760 0.00000 57822.00 0.00 0.00000 > 4902.24 12.00210 10.17850 0.00000 57822.00 0.00 0.00000 > 4952.58 12.03110 10.19780 0.00000 57822.00 0.00 0.00000 > 5002.91 12.05930 10.21540 0.00000 57822.00 0.00 0.00000 > 5053.24 12.08670 10.23120 0.00000 57822.00 0.00 0.00000 > 5103.57 12.11330 10.24540 0.00000 57822.00 0.00 0.00000 > 5153.90 12.13910 10.25780 0.00000 57882.00 0.00 0.00000 > 5153.90 12.70370 11.09140 3.43850 445.00 85.00 0.00000 > 5204.61 12.72890 11.10360 3.44880 444.00 85.00 0.00000 > 5255.32 12.75300 11.11530 3.45870 443.00 85.00 0.00000 > 5306.04 12.77600 11.12650 3.46810 441.00 85.00 0.00000 > 5356.75 12.79800 11.13710 3.47700 440.00 85.00 0.00000 > 5407.46 12.81880 11.14720 3.48560 439.00 85.00 0.00000 > 5458.17 12.83870 11.15680 3.49370 438.00 85.00 0.00000 > 5508.89 12.85740 11.16590 3.50130 437.00 85.00 0.00000 > 5559.60 12.87510 11.17450 3.50850 436.00 85.00 0.00000 > 5610.31 12.89170 11.18250 3.51530 436.00 85.00 0.00000 > 5661.02 12.90720 11.19010 3.52170 435.00 85.00 0.00000 > 5711.74 12.92170 11.19710 3.52760 434.00 85.00 0.00000 > 5762.45 12.93510 11.20360 3.53300 434.00 85.00 0.00000 > 5813.16 12.94740 11.20950 3.53810 433.00 85.00 0.00000 > 5863.87 12.95860 11.21500 3.54270 433.00 85.00 0.00000 > 5914.59 12.96880 11.21990 3.54680 432.00 85.00 0.00000 > 5965.30 12.97790 11.22430 3.55050 432.00 85.00 0.00000 > 6016.01 12.98590 11.22820 3.55380 432.00 85.00 0.00000 > 6066.72 12.99290 11.23160 3.55670 432.00 85.00 0.00000 > 6117.44 12.99880 11.23450 3.55910 431.00 85.00 0.00000 > 6168.15 13.00360 11.23680 3.56100 431.00 85.00 0.00000 > 6218.86 13.00740 11.23860 3.56260 431.00 85.00 0.00000 > 6269.57 13.01000 11.23990 3.56370 431.00 85.00 0.00000 > 6320.29 13.01170 11.24070 3.56430 0.00 0.00 0.00000 > 6371.00 13.01220 11.24090 3.56450 0.00 0.00 0.00000 > >This is the PREM model: > > 0.00 2.60000 5.80000 3.20000 1456.00 600.00 0.00000 > 15.00 2.90000 6.80000 3.90000 1350.00 600.00 0.00000 > 24.40 2.90000 6.80000 3.90000 1350.00 600.00 0.00000 > 24.40 3.38076 8.11061 4.49094 1446.00 600.00 0.00000 > 40.00 3.37906 8.10119 4.48486 1446.00 600.00 0.00000 > 60.00 3.37688 8.08907 4.47715 1447.00 600.00 0.00000 > 80.00 3.37471 8.07689 4.46954 1447.00 600.00 0.00000 > 80.00 3.37471 8.07688 4.46953 195.00 80.00 0.00000 > 115.00 3.37091 8.05540 4.45643 195.00 80.00 0.00000 > 150.00 3.36710 8.03370 4.44361 195.00 80.00 0.00000 > 185.00 3.36330 8.01180 4.43108 195.00 80.00 0.00000 > 220.00 3.35950 7.98970 4.41885 195.00 80.00 0.00000 > 220.00 3.43578 8.55896 4.64391 362.00 143.00 0.00000 > 265.00 3.46264 8.64552 4.67540 365.00 143.00 0.00000 > 310.00 3.48951 8.73209 4.70690 367.00 143.00 0.00000 > 355.00 3.51639 8.81867 4.73840 370.00 143.00 0.00000 > 400.00 3.54325 8.90522 4.76989 372.00 143.00 0.00000 > 400.00 3.72378 9.13397 4.93259 366.00 143.00 0.00000 > 450.00 3.78678 9.38990 5.07842 365.00 143.00 0.00000 > 500.00 3.84980 9.64588 5.22428 364.00 143.00 0.00000 > 550.00 3.91282 9.90185 5.37014 363.00 143.00 0.00000 > 600.00 3.97584 10.15782 5.51602 362.00 143.00 0.00000 > 635.00 3.98399 10.21203 5.54311 362.00 143.00 0.00000 > 670.00 3.99214 10.26662 5.57020 362.00 143.00 0.00000 > 670.00 4.38071 10.75131 5.94508 759.00 312.00 0.00000 > 721.00 4.41241 10.91005 6.09418 744.00 312.00 0.00000 > 771.00 4.44317 11.06557 6.24046 730.00 312.00 0.00000 > 871.00 4.50372 11.24490 6.31091 737.00 312.00 0.00000 > 971.00 4.56307 11.41560 6.37813 743.00 312.00 0.00000 > 1071.00 4.62129 11.57828 6.44232 750.00 312.00 0.00000 > 1171.00 4.67844 11.73357 6.50370 755.00 312.00 0.00000 > 1271.00 4.73460 11.88209 6.56250 761.00 312.00 0.00000 > 1371.00 4.78983 12.02445 6.61891 766.00 312.00 0.00000 > 1471.00 4.84422 12.16126 6.67317 770.00 312.00 0.00000 > 1571.00 4.89783 12.29316 6.72548 775.00 312.00 0.00000 > 1671.00 4.95073 12.42075 6.77606 779.00 312.00 0.00000 > 1771.00 5.00299 12.54466 6.82512 784.00 312.00 0.00000 > 1871.00 5.05469 12.66550 6.87289 788.00 312.00 0.00000 > 1971.00 5.10590 12.78389 6.91957 792.00 312.00 0.00000 > 2071.00 5.15669 12.90045 6.96538 795.00 312.00 0.00000 > 2171.00 5.20713 13.01579 7.01053 799.00 312.00 0.00000 > 2271.00 5.25729 13.13055 7.05525 803.00 312.00 0.00000 > 2371.00 5.30724 13.24532 7.09974 807.00 312.00 0.00000 > 2471.00 5.35706 13.36074 7.14423 811.00 312.00 0.00000 > 2571.00 5.40681 13.47742 7.18892 815.00 312.00 0.00000 > 2671.00 5.45657 13.59597 7.23403 819.00 312.00 0.00000 > 2741.00 5.49145 13.68041 7.26597 822.00 312.00 0.00000 > 2771.00 5.50642 13.68753 7.26575 823.00 312.00 0.00000 > 2871.00 5.55641 13.71168 7.26486 826.00 312.00 0.00000 > 2891.00 5.56645 13.71660 7.26466 826.00 312.00 0.00000 > 2891.00 9.90349 8.06482 0.00000 57882.00 0.00 0.00000 > 2971.00 10.02940 8.19939 0.00000 57822.00 0.00 0.00000 > 3071.00 10.18134 8.36019 0.00000 57822.00 0.00 0.00000 > 3171.00 10.32726 8.51298 0.00000 57822.00 0.00 0.00000 > 3271.00 10.46727 8.65805 0.00000 57822.00 0.00 0.00000 > 3371.00 10.60152 8.79573 0.00000 57822.00 0.00 0.00000 > 3471.00 10.73012 8.92632 0.00000 57822.00 0.00 0.00000 > 3571.00 10.85321 9.05015 0.00000 57822.00 0.00 0.00000 > 3671.00 10.97091 9.16752 0.00000 57822.00 0.00 0.00000 > 3771.00 11.08335 9.27876 0.00000 57822.00 0.00 0.00000 > 3871.00 11.19067 9.38418 0.00000 57822.00 0.00 0.00000 > 3971.00 11.29298 9.48409 0.00000 57822.00 0.00 0.00000 > 4071.00 11.39042 9.57881 0.00000 57822.00 0.00 0.00000 > 4171.00 11.48311 9.66865 0.00000 57822.00 0.00 0.00000 > 4271.00 11.57119 9.75393 0.00000 57822.00 0.00 0.00000 > 4371.00 11.65478 9.83496 0.00000 57822.00 0.00 0.00000 > 4471.00 11.73401 9.91206 0.00000 57822.00 0.00 0.00000 > 4571.00 11.80900 9.98554 0.00000 57822.00 0.00 0.00000 > 4671.00 11.87990 10.05572 0.00000 57822.00 0.00 0.00000 > 4771.00 11.94682 10.12291 0.00000 57822.00 0.00 0.00000 > 4871.00 12.00989 10.18743 0.00000 57822.00 0.00 0.00000 > 4971.00 12.06924 10.24959 0.00000 57822.00 0.00 0.00000 > 5071.00 12.12500 10.30971 0.00000 57822.00 0.00 0.00000 > 5149.50 12.16634 10.35568 0.00000 57822.00 0.00 0.00000 > 5149.50 12.76360 11.02827 3.50432 445.00 85.00 0.00000 > 5171.00 12.77493 11.03643 3.51002 445.00 85.00 0.00000 > 5271.00 12.82501 11.07249 3.53522 443.00 85.00 0.00000 > 5371.00 12.87073 11.10542 3.55823 440.00 85.00 0.00000 > 5471.00 12.91211 11.13521 3.57905 439.00 85.00 0.00000 > 5571.00 12.94912 11.16186 3.59767 437.00 85.00 0.00000 > 5671.00 12.98178 11.18538 3.61411 436.00 85.00 0.00000 > 5771.00 13.01009 11.20576 3.62835 434.00 85.00 0.00000 > 5871.00 13.03404 11.22301 3.64041 433.00 85.00 0.00000 > 5971.00 13.05364 11.23712 3.65027 432.00 85.00 0.00000 > 6071.00 13.06888 11.24809 3.65794 432.00 85.00 0.00000 > 6171.00 13.07977 11.25593 3.66342 431.00 85.00 0.00000 > 6271.00 13.08630 11.26064 3.66670 431.00 85.00 0.00000 > > > The next step to getting an accurate representation of what you see on your >seismogram is a method called "synthetic seismograms" which uses a >finite-element modelling technique to generate a seismogram based on the >information you have given, like the earth model, source mechanism, and any >departures from the model between the station and the quake. The earthquake >source tells you how the elastic waves looked as they propagated out. There >are characteristic radiation patterns for waves leaving an ideal fault (double >couple) that are also used. > >****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > http://www.public.asu.edu/~hernlund/ > >****************************************************************************** > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@.............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email listserver@.............. with the body of the message: leave PSN-L From: John Hernlund Subject: Re: Reading Seismograms Date: Fri, 12 Mar 1999 15:37:01 -0700 (MST) On Fri, 12 Mar 1999, Dick Webb wrote: > John, > Thanks for the information about earth models. My question is a tad more > basic. When confronted with a seismogram what is the best way to approach > making picks IF YOU DON'T KNOW THE HYPOCENTER. Are there characteristic > shapes and relationships that would let one determine a P from a Pp and > even something so simple as an S wave. After all they must have used the > eyeball approach before the days of the internet or telemetry. Dick, Well, reading seismograms really well involves an intimate aquaintance with wave behavior and the earth models. The successful interpretation must be consistent with all of the facts. Keep in mind that interpreting seismograms is very difficult! I'll outline techniques and general rules to use to start interpreting these things, but beyond that I am not that good at interpreting these things myself! 1- Never use the onset of surface waves for your travel times. Surface waves are the largest features on a seismogram, and it is tempting to use them, but their travel paths are complicated by changes in the crust and upper mantle. 2- You will never know for sure if your arrivals are S or P type unless you have at least two well-oriented seismographs and in general you must have all three components of ground motion and have instruments that have the same ground response. 3- If you have three components, then you can make vector plots (also called particle motion plots) of two component directions for any direction you want by using linear algebra (rotation matrix). These will help you understand what direction the ground was moving in three dimensions. A first P-wave arrival will always produce a particle motion that points down back toward the epicenter. The S-wave motions will in general be nearly perpendicular to the P-wave direction. If the first P-wave arrival is up and down motion then the epicenter is on the opposite side of the Earth. If it is nearly horizontal then the earthquake is fairly close. 4- Waves do not leave the earthquake source nicely. The fault that generated the quake probably did not move smoothly, but rather in small steps and jumps. Also, the fault is not a single point but a planar feature, so tha