From: John Hernlund Subject: Re: [Fwd: [Fwd: Pymatuning, Ohio, Earthquake]] Date: Wed, 30 Sep 1998 14:28:29 -0700 (MST) Edward or Anyone Else, I take it there must not have been enough good data for a moment tensor solution? I have not seen one available, and I think it would be extremely interesting... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ "It is easier to excuse an ignorant person who claims that theory is unnecessary and dispensable in his supposed practice, than to excuse a Sophist who concedes its value to the schools (as, perhaps, only a mental exercise) but who at the same time maintains that matters are quite different in practice- that as one leaves school to enter the world, one will realize one has been pursuing empty ideals and philosophical dreams- and, in a word, that what sounds good in theory is of no practical use." -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No Practical Use ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: [Fwd: [Fwd: Pymatuning, Ohio, Earthquake]] Date: Wed, 30 Sep 1998 16:30:47 -0600 John- I've been so up to my ass in digital and bureaucratic alligators with our own aftershock program, I haven't had a chance to check. Let me know what you find. -Edward John Hernlund wrote: > Edward or Anyone Else, > I take it there must not have been enough good data for a moment tensor > solution? I have not seen one available, and I think it would be extremely > interesting... > > ****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > http://www.public.asu.edu/~hernlund/ > > "It is easier to excuse an ignorant person who claims that theory is > unnecessary and dispensable in his supposed practice, than to excuse a > Sophist who concedes its value to the schools (as, perhaps, only a mental > exercise) but who at the same time maintains that matters are quite > different in practice- that as one leaves school to enter the world, one > will realize one has been pursuing empty ideals and philosophical dreams- > and, in a word, that what sounds good in theory is of no practical > use." > -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No > Practical Use > > ****************************************************************************** > > _____________________________________________________________________ > > 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) From: "Walt Williams" Subject: Those Pesky Little Geophones Date: Wed, 30 Sep 1998 19:49:22 +0000 Hello All, (they're back!) Could someone recommend book or paper which describe the geophone sensor? Thank you. Walt Williams, 98.09.30 dfheli@.............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: PSN-L: MagneTar Date: Wed, 30 Sep 1998 21:05:49 +0000 From: setv-l@........ To: seti-l@......... "'CS'" , "'FPS'" fpspace@.................>, "'ST'" Copies to: "'Don2'" , '''SK'" , "'ScottC'" Date sent: Wed, 30 Sep 1998 01:19:18 +0000 Subject: SETV-L:Tremendous GAMMA-Ray Flare Blasts Earth Send Copies to: Walt Williams Priority: normal Subject: SETI FW: TREMENDOUS GAMMA-RAY FLARE BLASTS EARTH Date sent: Tue, 29 Sep 1998 14:22:15 -0400 ---------- From: NASANews@........... Sent: Tuesday, September 29, 1998 2:10 PM To: undisclosed-recipients:; Subject: TREMENDOUS GAMMA-RAY FLARE BLASTS EARTH Donald Savage Headquarters, Washington, DC Sept. 29, 1998 (Phone: 202/358-1547) Tim Tyson Marshall Space Flight Center, Huntsville, AL (Phone: 256/544-0994) RELEASE: 98-172 TREMENDOUS GAMMA-RAY FLARE BLASTS EARTH An intense wave of gamma rays, emanating from a catastrophic magnetic flare on a mysterious star 20,000 light years away, struck the Earth's atmosphere on August 27, 1998, providing important clues about some of the most unusual stars in the Universe. Scientists said the gamma radiation posed no health risk to humans. The wave hit the night side of the Earth and ionized (or knocked electrons out of) the atoms in the upper atmosphere to a level usually seen only during daytime. This astonishing blast of ionization was detected by Prof. Umran Inan of Stanford University. "It is extremely rare for an event occurring outside the solar system to have any measurable effect on the Earth," Inan said. It was so powerful that it blasted sensitive detectors to maximum or off-scale on at least seven scientific spacecraft in Earth orbit and around the solar system. The wave of radiation emanated from a newly discovered type of star called a magnetar. Magnetars are dense balls of super- heavy matter, no larger than a city but weighing more than the Sun. They have the greatest magnetic field known in the Universe, so intense that it powers a steady glow of X-rays from the star's surface, often punctuated by brief, intense gamma-ray flashes, and occasionally by cataclysmic flares like the one observed on August 27. Astronomers think that all these effects are caused by an out-of-control magnetic field -- a field capable of heating, mixing, and sometimes cracking the star's rigid surface to bits. In June a team of scientists led by Dr. Chryssa Kouveliotou of NASA's Marshall Space Flight Center in Huntsville, AL, used NASA's Compton Gamma Ray Observatory to detect a series of about 50 flashes from the star, a type called a Soft Gamma Repeater (SGR), known as "SGR1900+14" in the constellation Aquila. During the flashing episode, Kouveliotou's team, in collaboration with Dr. Tod Strohmayer and his colleagues at NASA's Goddard Space Flight Center, Greenbelt, MD, pointed sensitive X-ray detectors aboard NASA's Rossi X-ray Timing Explorer satellite toward the star. They found faint X-rays coming from the star, which pulsed regularly in intensity every 5.16 seconds. These 5.16-second pulses already had been detected in April, when Dr. Kevin Hurley, University of California, Berkeley, aimed the Japanese/NASA Advanced Satellite for Cosmology and Astrophysics (ASCA) at the star. Comparisons of the ASCA and RXTE data showed that the X-ray pulses were gradually slowing down. The finding implies that the Soft Gamma Repeater has a magnetic field about 800 trillion times stronger than Earth's magnetic field, and about 100 times stronger than any found anywhere in the Universe. Kouveliotou and her team had earlier found that another SGR was also a magnetar. This was exactly what Dr. Robert Duncan, University of Texas, Austin, and Dr. Christopher Thompson, University of North Carolina, Chapel Hill, predicted in 1992 when they originated the "magnetar" theory. Before the NASA team could announce these conclusions, SGR1900+14 emitted the tremendous flare of August 27, which was observed by almost every spacecraft with a high-energy radiation detector in space. "Magnetars seem to answer several mysteries about the structure and evolution of stars," said Kouveliotou. "We think magnetars spend their first 10,000 years as Soft Gamma Repeaters. As they weaken with age and slow their rotation, they become Anomalous X-ray Pulsars -- stars that do not have enough 'juice' to flash anymore, but which emit a steady flow of X-rays for perhaps another 30,000 years. After that, they fade to black and drift for eternity through the heavens. The absence of observable pulsars in some supernova remnants just means that the pulsar's lights have gone out sooner than we expected." A magnetar forms from the explosion, or supernova, of a very large, ordinary star. The star's heavy center collapses under its own gravity into a dense ball of super-compressed matter 12 miles across. This "neutron star" consists mostly of neutrons in a dense fluid, but the outer layers solidify into a rigid crust of atoms about 1 mile deep, with a surface of iron. Even with this solid crust, a magnetar is incredibly unstable. Almost unimaginable magnetic fields, about 800 trillion times that of Earth's, cause the crust to crack and ripple in powerful starquakes. The energy released in these explosive starquakes streams out into space as intense flashes of gamma- rays. In the August 27 flare, pure magnetic energy was also released, as the star's entire crust was broken to bits. "A magnet this strong could erase the magnetic strip on the credit cards in your wallet or pull the keys out of your pocket from a distance halfway to the Moon," said Duncan. - end - EDITOR'S NOTE: Additional information on magnetars or the Aug. 27 event is available on the internet at: http://www1.msfc.nasa.gov/NEWSROOM/ and http://www.magnetars.com/ * * * NASA press releases and other information are available automatically by sending an Internet electronic mail message to domo@............ In the body of the message (not the subject line) users should type the words "subscribe press-release" (no quotes). The system will reply with a confirmation via E-mail of each subscription. A second automatic message will include additional information on the service. NASA releases also are available via CompuServe using the command GO NASA. To unsubscribe from this mailing list, address an E-mail message to domo@............ leave the subject blank, and type only "unsubscribe press-release" (no quotes) in the body of the message. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Greg Subject: Re: Those Pesky Little Geophones Date: Wed, 30 Sep 1998 22:03:33 -0700 Walt Williams wrote: > Could someone recommend book or paper which describe the > geophone sensor? I still have my sorry little FAQ up at: http://www.treefort.org/~ghost/geo.html You probably wanted something a bit more detailed... let me know what it is when you find it. ;) ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: Those Pesky Little Geophones Date: Thu, 1 Oct 1998 11:29:29 EDT Hello, Try "ENCYCLOPEDIC DICTIONARY OF EXPLORATION GEIOPHYSICS" by R. E. Sheriff published by the Society of Exploration Geophysics, Tulsa OK, U. S. A. In a message dated 98-09-30 22:54:30 EDT, dfheli@.............. writes: << Could someone recommend book or paper which describe the geophone sensor? >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@.................. Subject: Mechanism of the Pymatuning, Ohio, Earthquake Date: Thu, 1 Oct 1998 09:30:46 -0600 (MDT) The Harvard mechanism indicates predominantly thrust due to northeast-southwest compression. JCLahr > From sipkin@gldage Thu Oct 1 09:25 MDT 1998 > Date: Thu, 1 Oct 1998 09:25:25 -0600 > From: sipkin@gldage (Stuart Sipkin) > To: lahr@.................. > Subject: Re: Ohio/Penn. EQ > > John, > > The following is from Harvard. > > Stuart > > ------------------------------------------------------------------------------- > > Here is a preliminary CMT solution for the recent OHIO earthquake. The solution > is calculated from intermediate period surface waves recorded on the USGS > National Seismic Network. > > September 25, OHIO, Mw=4.5 > > Goran Ekstrom > > CENTROID, MOMENT TENSOR SOLUTION > HARVARD EVENT-FILE NAME B092598X > DATA USED: NSN > L.P. BODY WAVES: 17S, 25C, T= 32 > CENTROID LOCATION: > ORIGIN TIME 19:52:55.3 0.2 > LAT 41.43N 0.04;LON 80.41W 0.03 > DEP 12.0 FIX;HALF-DURATION 1.0 > MOMENT TENSOR; SCALE 10**22 D-CM > MRR= 4.83 0.67; MTT= 0.95 0.71 > MFF=-5.77 0.31; MRT=-0.20 0.99 > MRF=-0.39 0.92; MTF= 5.92 0.38 > PRINCIPAL AXES: > 1.(T) VAL= 5.04;PLG=60;AZM=148 > 2.(N) 4.18; 30; 330 > 3.(P) -9.23; 1; 240 > BEST DOUBLE COUPLE:M0=7.1*10**22 > NP1:STRIKE=303;DIP=51;SLIP= 51 > NP2: 176; 53; 128 > > ###-------- > ######------------- > #######---------------- > ###-----#------------------ > --------########------------- > ---------###########----------- > --------##############--------- > ---------################-------- > ---------##################------ > ---------###################----- > ---------######### ########---- > ---------######## T #########-- > ------######## #########-- > P -------###################- > --------################## > --------############### > -------############ > -----###### > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Mechanism of the Pymatuning, Ohio, Earthquake Date: Thu, 01 Oct 1998 12:17:57 -0600 John- I heard from someone that there was a large non-double-couple component to the mechanism (which could be the apparent result caused by near-surface, high-frequency wave-propagation complexities) which suggested that the event may have been caused by a collapse rather than by slip on a fault plane, and, hence, aftershocks are not to be expected. However, I believe that large collapses are dangerous and also need to be investigated. -Edward lahr@.................. wrote: > The Harvard mechanism indicates predominantly thrust due > to northeast-southwest compression. > > JCLahr > > > From sipkin@gldage Thu Oct 1 09:25 MDT 1998 > > Date: Thu, 1 Oct 1998 09:25:25 -0600 > > From: sipkin@gldage (Stuart Sipkin) > > To: lahr@.................. > > Subject: Re: Ohio/Penn. EQ > > > > John, > > > > The following is from Harvard. > > > > Stuart > > > > ------------------------------------------------------------------------------- > > > > Here is a preliminary CMT solution for the recent OHIO earthquake. The solution > > is calculated from intermediate period surface waves recorded on the USGS > > National Seismic Network. > > > > September 25, OHIO, Mw=4.5 > > > > Goran Ekstrom > > > > CENTROID, MOMENT TENSOR SOLUTION > > HARVARD EVENT-FILE NAME B092598X > > DATA USED: NSN > > L.P. BODY WAVES: 17S, 25C, T= 32 > > CENTROID LOCATION: > > ORIGIN TIME 19:52:55.3 0.2 > > LAT 41.43N 0.04;LON 80.41W 0.03 > > DEP 12.0 FIX;HALF-DURATION 1.0 > > MOMENT TENSOR; SCALE 10**22 D-CM > > MRR= 4.83 0.67; MTT= 0.95 0.71 > > MFF=-5.77 0.31; MRT=-0.20 0.99 > > MRF=-0.39 0.92; MTF= 5.92 0.38 > > PRINCIPAL AXES: > > 1.(T) VAL= 5.04;PLG=60;AZM=148 > > 2.(N) 4.18; 30; 330 > > 3.(P) -9.23; 1; 240 > > BEST DOUBLE COUPLE:M0=7.1*10**22 > > NP1:STRIKE=303;DIP=51;SLIP= 51 > > NP2: 176; 53; 128 > > > > ###-------- > > ######------------- > > #######---------------- > > ###-----#------------------ > > --------########------------- > > ---------###########----------- > > --------##############--------- > > ---------################-------- > > ---------##################------ > > ---------###################----- > > ---------######### ########---- > > ---------######## T #########-- > > ------######## #########-- > > P -------###################- > > --------################## > > --------############### > > -------############ > > -----###### > > > > _____________________________________________________________________ > > 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) From: John Hernlund Subject: Re: Mechanism of the Pymatuning, Ohio, Earthquake Date: Thu, 01 Oct 1998 11:57:46 -0700 (MST) On Thu, 1 Oct 1998, Edward Cranswick wrote: > I heard from someone that there was a large non-double-couple component > to the mechanism (which could be the apparent result caused by near-surface, > high-frequency wave-propagation complexities) which suggested that the event > may have been caused by a collapse rather than by slip on a fault plane, > and, hence, aftershocks are not to be expected. However, I believe that > large collapses are dangerous and also need to be investigated. > -Edward That is very interesting indeed. The depth is given as 12.0 below, which would have to mean something collapse-able survived to that depth, provided that the depth is accurate. Are there any inferences from cross-sections, etc. that might guess what kind of structure is down there? I would guess mostly metamorphics, possibly metasedimentary rocks? I wonder how many old faults from the Appalachian episode might exist on the West side of the mountains... > > The Harvard mechanism indicates predominantly thrust due > > to northeast-southwest compression. > > > DEP 12.0 FIX;HALF-DURATION 1.0 > > > MOMENT TENSOR; SCALE 10**22 D-CM > > > BEST DOUBLE COUPLE:M0=7.1*10**22 > > > NP1:STRIKE=303;DIP=51;SLIP= 51 > > > NP2: 176; 53; 128 > > > ###-------- > > > ######------------- > > > #######---------------- > > > ###-----#------------------ > > > --------########------------- > > > ---------###########----------- > > > --------##############--------- > > > ---------################-------- > > > ---------##################------ > > > ---------###################----- > > > ---------######### ########---- > > > ---------######## T #########-- > > > ------######## #########-- > > > P -------###################- > > > --------################## > > > --------############### > > > -------############ > > > -----###### ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ "It is easier to excuse an ignorant person who claims that theory is unnecessary and dispensable in his supposed practice, than to excuse a Sophist who concedes its value to the schools (as, perhaps, only a mental exercise) but who at the same time maintains that matters are quite different in practice- that as one leaves school to enter the world, one will realize one has been pursuing empty ideals and philosophical dreams- and, in a word, that what sounds good in theory is of no practical use." -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No Practical Use ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: BZIMMERMAN@............ Subject: Re: Mechanism of the Pymatuning, Ohio, Earthquake Date: Thu, 01 Oct 1998 15:10:29 -0500 (EST) If you move closer to the surface the Salina Group salt beds come into play. Depth 3,000-5,000 feet here in Erie County and geetting deeper as you go south. How precise is the depth determination ? Brian Zimmerman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Mechanism of the Pymatuning, Ohio, Earthquake Date: Thu, 01 Oct 1998 12:41:02 -0700 (MST) On Thu, 1 Oct 1998 BZIMMERMAN@............ wrote: > If you move closer to the surface the Salina Group salt beds come into > play. Depth 3,000-5,000 feet here in Erie County and geetting deeper as > you go south. > How precise is the depth determination ? Since local coverage is very poor, and the body waves complicated further as mentioned before I am sure it probably isn't very good. I like the idea of salt beds though... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ "It is easier to excuse an ignorant person who claims that theory is unnecessary and dispensable in his supposed practice, than to excuse a Sophist who concedes its value to the schools (as, perhaps, only a mental exercise) but who at the same time maintains that matters are quite different in practice- that as one leaves school to enter the world, one will realize one has been pursuing empty ideals and philosophical dreams- and, in a word, that what sounds good in theory is of no practical use." -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No Practical Use ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Hall scanned circuit/s is on web site Date: Thu, 01 Oct 1998 14:07:15 -0600 Hi guys, Now have rough scanned circuits of Robert Lamb's Hall amplifier on my web site. The main amplifier needs to be redrawn, but the gist of it is there. Redrew the simplified meter circuit. Thats all the electronics involved. No power supply circuit drawn and its presumed to be other equipment. The 10K resistor coming off terminal 9 feeds directly into Larry Cochranes board & SDR program; other programs/boards may have to be adjusted however. http://www.geocities.com/ResearchTriangle/Facility/1739/index.html The web site needs a gob more detail with the circuit description and operation, parts list, etc. Eventually it will come. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: vbb zero drift Date: Thu, 1 Oct 1998 18:59:18 -0500 (CDT) Barry, Regarding your questions about the need for frequent recentering of your VBB instrument and how this is done with commercial units: The key parameter that effects the thermal stability is the operating period. A 100 second sensor will be about 10 times more of a problem than a 10 second sensor, everything else being equal. So every effort is made in the design to reduce mechanical thermal effects as much as possible. This is one of the reasons that the commercial units are so expensive. But even when the commercial units specify an operating range of +,- 10 degC without re-zeroing, it actually means that the mass or boom will move through its full range during that temperature change. For these sensors, the mass position voltage may range +- 10 volts, but the diurnal earth tides may be 1% of this, equilavent to a temperature change of only 0.1 degC, which, of course, must be much less than this if one wants to record the tides without thermal noise. This is why very careful site selection and elaborate site prepartions are necessary, and sites in deep vaults or caverns are preferable. Link from the PSN site page re. "information, equipment, and software" to the "Guidelines for Installing Broadband Seismic Stations" by the Berkeley Seismo. Lab for a detailed discussion. In general the insulation, etc, should be sufficient so that no daily thermal effects are seen, but seasonal temperature changes might require recentering. The commercial sensors have automatic re-centering features that either drive a miniature motor or apply a DC correction to the displacement detector output. They also have a relatively long time recommended for them to reach thermal stability, like several days. The commercial sensors generally are digitized with 24-bit resolution, or 1 part per 16 million, so the output is always on-scale. The DC offset caused by temperature is removed in processing. But for 16-bit digitizers, a high-pass filter is necessary to keep the data within the range of the digitizer. If the filter period is at least 10 times the longest period of the data, it will not affect the response. So for the 100-second STM-8, I use a 2000-second (2x 4000 ufarad in series, with 1 megohm, a single-pole) high pass coupling into the output amplifier. My RS multimeter digitizer is +,- 200 mv full scale, with the LSB being 0.1 millivolt; the daily temperature drift of the VBB output ranges from 0.1 to 1 volt, but the filter keeps this from the digitizer. I haven't had to re-center the sensor operating in the basement for several weeks, although its output has wandered around by several volts. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Mechanism of the Pymatuning, Ohio, Earthquake Date: Thu, 01 Oct 1998 20:11:24 -0600 Brian- Someone will quantify the depth uncertainty, I hope. Thank you for your remarks in your previous post; it was good to meet you. I think that, with your expertise in economic geology and your interest and knowledge of seismology in conjunction with your proximity, you are in a position to make a valuable contribution to the study of the Pymatuning Earthquake. -Edward BZIMMERMAN@............ wrote: > If you move closer to the surface the Salina Group salt beds come into > play. Depth 3,000-5,000 feet here in Erie County and geetting deeper as > you go south. > > How precise is the depth determination ? > > Brian Zimmerman > > _____________________________________________________________________ > > 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) From: Greg Subject: Re: Dataq acquisition module Date: Fri, 02 Oct 1998 04:53:20 +0000 Gregory Bajuk wrote: > Dataq Instruments has an Internet special price promotion on a serial port > data acquisition module DI-150. Features 2 channels, +/- 10 volt input, The internet special is for the DI-150-SP. They also sell the DI-150-RS. The SP model is not stable in the +-100mv range. Luckily I got a sales guy that knew what was going on. Hopefully nobody bought something that they didn't want. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Steve Carniglia" Subject: Re: Dataq acquisition module Date: Fri, 2 Oct 1998 08:14:10 -0700 I sent the board to Ted Blank.....he tried to make his software work = with the DI190...He felt that the problem was in the video graphics area = so his software would not work. Other than that, Ted was able to see = the board. I do not know about the other software out there...please = let me know if you know of software that is compatible.... Thanks Steve =20 -----Original Message----- From: Francesco To: PSN-L Mailing List Date: Wednesday, September 30, 1998 11:22 AM Subject: R: Dataq acquisition module =20 =20 Which problem have the board using our software (Sdr or Emon or Wq?) = ? =20 Regards Francesco Nucera
I sent the board to Ted Blank.....he = tried to=20 make his software work with the DI190...He felt that the problem was in = the=20 video graphics area so his software would not work.  Other than = that, Ted=20 was able to see the board.  I do not know about the other software = out=20 there...please let me know if you know of software that is=20 compatible....
 
Thanks
Steve
 
-----Original = Message-----
From:=20 Francesco <franuc@......>
To: = PSN-L=20 Mailing List <psn-l@.............>
Dat= e:=20 Wednesday, September 30, 1998 11:22 AM
Subject: R: = Dataq=20 acquisition module

Which problem have the board = using our=20 software (Sdr or Emon or Wq?) ?
 
Regards
Francesco=20 Nucera
From: GeE777@....... Subject: Re: Those Pesky Little Geophones Date: Fri, 2 Oct 1998 12:24:26 EDT Hi, This is taken grom "Seismic Exploration Fundamentals" by J. A. Coffeen p66,67 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Geophone A geophone is a device for detecting sounds from the earth--geo, earth; phone, sound. The type of geophone generally used in seismic exploration on land consists of a strong permanent magnet and a coil of wire, around the magnet, all in a rugged case. The magnet is attached rigidly to the case, which can also retain the magnetic field. The coil, made of fine copper wire wound many times around, is connected to the case by a spring. The geophone is placed in firm contact with the ground. Then any shaking of the ground will shake the case and magnet. The coil, suspended on its spring, will not move as quickly. So the magnet moves up and down past the coil. Relative movement between magnet and coil generates electric current, on this small scale, just as it does in the dynamoes that power cities. The ends of the coil are connected to a "pigtail", a pair of wires extending from the case. to be connected, through the cable, to the recording equipment. The bits of current generated by the movements of the magnet make up the signal from the geophone. They are in proportion to the speed the magnet moves past the coil, so this type of detector is called a velocity geophone. Geophones are set out by recording helpers, "jug hustlers". The "string" of geophones for a group is put on the ground at a set distance from each other. Good contact with the ground is assured. Geophones often have spikes on the bottom, so they can be stabbed into the ground. For frozen ground, they may be flat-bottomed, and need to be pressed into place, or grass scraped aside. Assuring the good contact is "planting" the geophones. A good plant is one in which the contact will allow vibration to be transmitted well from the earth to the geophone. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I am retired from a major oil company research department. I have 8 patents concerning geophones. My expermints indicate that if a geophone can easilly be buried 10 to 20 cm below the surface, there is a much better coupling than on the surface. It is best to remove the "spike" before burying the geophone. This gives the geophone a better impedance match with the earth. You must remember, that most of the time we in the exploration industry are looking for higher frequencies than in the natural seismic studies. George Erich _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: new, revised schematics for VRDT Date: Fri, 2 Oct 1998 20:36:57 -0500 (CDT) Re: VBB schematics: I have just scanned some new and revised schematic drawings regarding the VRDT displacement detector for the VBB seismometer. The drawings are found on the "figures, schematics, drawings ..." page at: http://www.eas.slu.edu/People/STMorrissey/index.html Fig 5 is a hopefully final update of the precision sine wave oscillator that is used (at 5 khz output) with the VRDT. Fig 6 is a NEW drawing showing the connections of the VRDT in the bridge circuit between the oscillator and the amplifier/demodulator. Fig 7 is a final update of the bridge amplifier/demodulator/ DC amplifier, with specific attention to use with a VRDT. Fig 13 shows the results of a sine wave calibration of the 90-second VBB sensor compared with the response indicated by the transfer function. Fig 14 is a plot of the digital data for the sine calibration. A "constant velocity" method was used, which is explained. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rex Klopfenstein, Jr." Subject: VBB Schematics Date: Sat, 03 Oct 1998 11:47:06 -0400 Thanks a lot for the updated schematics, this really pulls the VBB electronics together! I would also like your opinion on breadboarding techniques. I have been using vector board (perf board with holes on .01" centers), IC sockets, and vector clips (small clips that are pushed into .01" holes of perf board & components are soldered on one side, wiring on other). I have been looking into a new system that works with surface-mount components, but it is rather expensive. Everything is soldered on small boards that are then attached to a large board that acts as a ground plane I realize that the above technique has to be done with some thought for high frequency applications; such as, 'large' power feeds (star connections) and try to avoid 'long' parallel runs. What about low noise techniques? I realize that an etched pc board is the best, but for one-shot applications it isn't economically feasible. Rex Klopfenstein, Jr Bowling Green, OH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: vbb zero drift Date: Sat, 03 Oct 1998 10:21:26 -0700 Sean Thomas Thanks for the info on the commercial units. It would be nice to be able to set a unit down in the field in a reasonably level site and walk away. I am still hopefull. Regards Barry PS I picked up a small FB accelerometer from a gentleman with a company called CFX out of Pennsylvania. I have it hooked up adjacent to my VBB and Lehman. The output calibration shows a flat output from DC to 25 hz. It didn't pick up a 4.7 event in S. Cal @ 677k (did with Lehman) but I am hopeful on a teleseismic event. It did pick up a local Redding 3.1 event. It's about 1" in diameter and about 1.5" tall. It wasn't cheap ($170). It requires 6-12 vts @ about 8 ma. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: prototype PC boards Date: Sat, 3 Oct 1998 13:52:30 -0500 (CDT) Rex, RE. prototyping circuit boards, aka one-of-a-kind specials: For quick evaluation of circuits I have been using the solderless breadboards (the square white push-in boards, as in Newark pg 1579, similarly available at Radio Shack) for many years. They can have flaky connections, especially if oversize wires/leads are forced into the holes, or if they have been exposed to dampness. THey can handle a few to a dozen ICs. But for a permanent prototype, or a few special circuits with ICs, I use the Vector boards that have some pre-printed foil patterns on one side, such as their 3677-6 (Newark pg 547, $21 for a 4.5 x 8" board). I cut them to size with an office paper cutter. There are many patterns available, but this seems to be the most generic, and the continuous busses can be used for DC supplies or ground. I have tried their spring-clip mounting, but they are unreliable the long run. I prefer to have things soldered in, and to use good quality IC sockets. I use "solder wick" to remove or change components, or a header in an IC socket for an experimental set of Rs and Cs for such things as a filter. For some digital interfaces, I have used the same boards with IC sockets with wire-wrap pins, and headers for components, and they have worked for years. But I think that a fully soldered epoxy-base board with quality IC sockets is just as good as an etched PC board wrt noise, etc., and we certainly are not pushing any high frequency considerations. I have little experience with the surface mount prototyping, since It seems to lock one into a rather inflexible style and component choice. My old eyes prefer more visible components anyhow. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.................... (Frank Condon) Subject: Salton Sink Hot-Spot Date: Sat, 3 Oct 1998 12:12:31 -0700 (PDT) Hello: I need you all to evaluate this GOES satellite information as relayed to me through the University of Hawaii Hot-Spot Web Page. Apparently, "Bombay Beach" is showing something that indicates to them possible volcanic activity under the Salton Sea. Note: the use of the word "Anaheim." Why isn't it titled as to the proper location under the Salton Sea? http://volcano1.pgd.hawaii.edu/goes/anaheim/latest.shtml What is this all about? Frank Condon "Located in the seismic corridor somewhere between Fontana and Mammoth Lakes" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Breadboard techniques Date: Sat, 03 Oct 1998 12:40:13 -0700 Rex, you asked: =93I would also like your opinion on breadboarding techniques.=94 I would answer as follows: 1) Unless you have a space problem, I personally like the 0.1=94 hole center perf board because there are still huge quantities of parts with pinouts that fit this layout, from connectors to IC=92s. 2) When doing low frequency, perhaps 1 MHz or below, I use wire wrap, and above that frequency I start using point-to-point wire soldered on the pads. 3) And MOST IMPORTANT (and I cannot overemphasize this point) =96 Never use the plain perf board with just holes or holes with solder pads only. Get perf board with a ground plane on one side. This advice applies from DC to light! The ground plane is your best protection from all sorts of =93squirrely=94 behavior with problems ranging from hum to intermittent performance. At work I had special 9=94x9=94 breadboards la= id out and we buy them in quanity. I have only found two sources of something satisfactory in the marketplace. A few are Vector and generally are PC form factor plug-in breadboards with ground planes. These are in the $50 plus price range. The best deal I have found is from: Marlin P. Jones & Assoc. Inc. Phone: 561-848-8236 FAX: 561-844-8764 P.O.Box 12685 Lake Park, Florida 33403-0685 In their 98-4AB catalog on page 86 they have two 6.5=94 x 4.125=94 Proto cards, 0.062=94 Epoxy glass boards with ground plane one side and pads on the other side. I bought one of the 9033-PB boards and found it to be just fine. They are solder plated and routed to shape. Order no.: 9033-PB donut pads $8.95 9035-PB square pads $8.95 They have a $15.00 minimum order policy, but two of these boards will fill that. You can use most SMT parts on the 0.1=94 center pads since most IC=92s us= e 0.05=94 lead spacing. So you solder alternate leads to the adjacent pad row and the remaining leads to the next row over. I.e.: |______| -- IC U U U U -- leads O | O | O --0.1=94 center pads / / -- wire jumpers O O O --0.1=94 center pads Anyway, just a few comments on breadboarding. Hope they help. Charles R. Patton, Editor, Geo-Monitor _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Daryl P. Dacko" Subject: Re: Breadboard techniques Date: Sun, 04 Oct 1998 09:06:16 -0400 At 12:40 PM 10/3/98 -0700, you wrote: >3) And MOST IMPORTANT (and I cannot overemphasize this point) =96 Never >use the plain perf board with just holes or holes with solder pads >only. Get perf board with a ground plane on one side. This advice >applies from DC to light! The ground plane is your best protection from >all sorts of =93squirrely=94 behavior with problems ranging from hum to >intermittent performance.=20 I can get away without a ground plane, but I'm fairly good at laying out and adding enough bypass caps to stop such behavior... A very cheap, very good, but very ugly method of breadboarding is 'dead bug' style: Use unetched pc board with continious copper plateing and lay the IC's=20 on their back with the pin's (legs) straight up in the air. Use a=20 drop of instant glue to hold them in place. Solder componests directly to the pc board when you need a ground, and support the supply rails and long signal runs on bypass caps or high=20 ohmage resistors. Interconenct the components with their own leads or waste pieces of cut off leads. Probabaly the uglyest way to breadboard ever seen, but it has better=20 high frequency performance than any breadboarding system I've ever seen. I usually use two inch square pieces of board, with only one or two IC's on each 'module' and just interconnect as needed. This lets you try a=20 new low-noise front end, for example, while leaving the rest of your=20 lashup alone... Just another opinion/option/method ;') Daryl _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ACole65464@....... Subject: Re: Breadboard techniques Date: Sun, 4 Oct 1998 11:29:13 EDT Daryl, Thanks for sharing the "dead bug" idea for breadboarding electronic circuits. It sounds simple. Ideas for circuit fabrication covers an area of design that many of us need to hear about. Allan Coleman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: CARRJJ@....... Subject: Re: Breadboard techniques Date: Sun, 4 Oct 1998 13:09:40 EDT The problem with ground plane perf boards is component thru-lead shorts. Some catalogs where these things are sold also sell a little tool for scraping away the copper around a hole just a little bit. It helps a lot. Ditto on the comments about solving problems. Joe Carr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: circuit boards Date: Sun, 4 Oct 1998 13:45:02 -0500 (CDT) Re: perforated boards with ground planes: Quite obviously the ground plane helps the noise figure, but my experience with it tends to be more related to hidden shorts of component leads, etc.. I have not found it to be necessary for sub-audio (ie seismic) amplifiers, especially when proper power supply by-passing, etc, is used. And when a perf-board proto is turned into a printed/etched board, any double-sided layout ups the complication ante, both for printing/etching proofs of the artwork in our darkroom, or getting them printed/drilled commercially. The component side layout is simulated and tested by copying the layout in reverse through the translucent mylar sheet. Also, for noise protection, we have to assume that the circuit has some external metal shielding/enclosure, and that the noise is contained by proper filtering/bypassing of the signal/power leads at the connector. I have used a variation of the "dead bug" construction technique for lightning suppression modules. Lightning loves a circuit board, and will flash over the entire surface unless it it very clean and dry and properly coated, vaporizing the foil conductors as it goes. SO for the DC power and analogue data lightning protection modules, we use a single high-barrier terminal strip with insulated "turret" style connections, further insulated with shrink tube as they pass through the holes drilled in the box, and mount the larger components (Varistors, inductors, etc) adjacent to the strip (ie on the inside of the cover of the aluminum box) with large gobs of RTV sealant. Smaller components mount directly to the terminal strip. For the UHF/VHF antenna coupler, all the components "hang" between the UHF/N/or BNC connectors at each end. The lightning cannot "bypass" the devices by flashing over an epoxy PC board. By the way, the PC artwork of the circuits of the VRDT oscillator and demodulator are available, both as the 2x original, which I can reduce to 1x on a transparency with the copier. I also have the reversed 1x printing films that can be copied to a transparency, but the result is not dark or dense enough to print a photo-resist. There is some progress in consolidating all the VBB electronics into one or two PC cards that would be available commercially. I believe these will be done with a CAD layout. Timetable ??. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Lehmann sensor Date: Sun, 04 Oct 1998 22:01:41 -0600 You're a funny dude; hope your knees are still good. Ted Blank wrote: > Maybe the Lehman Scale could be defined in terms of how high you have to > jump in the garage to get a standard deflection on a Lehman sensor. -- 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) From: "David A. Nelson" Subject: Re: Breadboard techniques Date: Tue, 06 Oct 1998 10:44:35 +1200 At 09:06 AM 10/4/98 -0400, you wrote: >At 12:40 PM 10/3/98 -0700, you wrote: >>3) And MOST IMPORTANT (and I cannot overemphasize this point) =96 Never >>use the plain perf board with just holes or holes with solder pads >>only. Get perf board with a ground plane on one side. This advice >>applies from DC to light! The ground plane is your best protection from >>all sorts of =93squirrely=94 behavior with problems ranging from hum to >>intermittent performance.=20 I use Veroboard (perf woth copper strips ) for seismic work, building up to 3 preamp channels side by side, without any difficulty at all. As Sean said at the very low freqs involved with seismic work track to track inductance/capacitance is not a problem so therefore stability has not been a prob. In hi gain audio and RF u CANNOT use "Vero" perfboard as u will very quickly get instability. Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., =20 Green Is., Dunedin, =20 South Is.. New Zealand. =20 http://psn.quake.net/dave/home.htm =20 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) From: meredith lamb Subject: Re: circuit boards Date: Mon, 05 Oct 1998 21:16:12 -0600 S-T Morrissey wrote: > There is some progress in consolidating all the VBB electronics into > one or two PC cards that would be available commercially. I believe > these will be done with a CAD layout. Timetable ??. > > Regards, > Sean-Thomas > Sean-Thomas, Am probably pushing it; but can you elaborate more on this? thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Maximumius Glutomious Alligator bites Date: Mon, 05 Oct 1998 21:41:36 -0600 Edward Cranswick, Uhhh.....is there any cure out there in Ohio, for your bites? The weather back here in Colorado was only in the 50's today, and perhaps upon your return, the cool, will sooth the ruffles? Ha. Don't hear anything of aftershocks. Afterbites? Ha. Presume they send you off anywhere for these mainland quakes. Any interesting or noteworthy history stories to pass on of your experiences? Imagine some of the storys maybe quite interesting. Do you take gobs of equipment? Government plane? Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rex Klopfenstein, Jr." Subject: Seismometer Pictures Date: Tue, 06 Oct 1998 18:46:29 -0400 I found several web sites that have pictures of seismometer installations and equipement. These addresses point to homepages. At the Karlsruhe site, follow the Black Forest Observatory links http://www-gpi.physik.uni-karlsruhe.de http://www.geophys.uni-stuttgart.de Rex Klopfenstein, Jr Bowling Green, OH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: Seismometer Pictures Date: Tue, 06 Oct 1998 19:20:35 -0600 Rex Klopfenstein, Jr. wrote: > I found several web sites that have pictures of seismometer > installations and equipement. These addresses point to homepages. At > the Karlsruhe site, follow the Black Forest Observatory links > > http://www-gpi.physik.uni-karlsruhe.de > > http://www.geophys.uni-stuttgart.de > Rex, Went to the Stuttgart site and saw all. Nice "find" of a site with pictures. Perhaps the most "upsetting" was the pictures of the retired seismometers and equipment; including the type of Sprengnethers I use. Seems such a waste to just store them and not use them. Too add to the days mix of photos, I just got done with some web site construction of my own vault pictures. None have the covers off, but they aren't too bad I think. http://www.geocities.com/ResearchTriangle/Facility/1739/vault.html This site only has pictures and afew words; not like the Index.html, which seems to be overloaded-ha. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Easiest web site construction I've seen Date: Tue, 06 Oct 1998 20:35:19 -0600 Hi all, Been using the http://www.geocities.com free web site deal for acouple of weeks. What I have is mostly the "old" html code approach. Acouple of days ago, I tried their new "GeoBuilder" program for creating html files. With that program, you can say GOODBYE to html code typeing stuff....it is actually fun to use!! Point, click, type words...no html to enter. This is a beta program, and requires that you have a computer with at least 133mghz and 24mg of ram, and windows 95 or 98, and java capability stuff. If you're experienced with Windows 95 and file manager housekeeping stuff, this shouldn't be tough to use. Oh yes, you need Internet Explorer or Netscape versions 4.0 along with your ISP. One can make a web site using just the stuff they give you. Of course it would be enhanced with any other accessories like camera, scanner or whatnot..... The main drawback I have seen is that it seems to be toooo popular, as, their can be trouble getting through on weekdays, weekends seem to be the best time to play with the program, or perhaps late at night. The last msg mention (RE:Seismometer Pictures) of the vault.html, is a example of the GeoBuilder program. Underneath that is a huge gob of html code, that the program creates by itself. One can reduce or enlarge or move pictures without leaving the program! Soooo.....if you have the right equipment, try it out, or keep it in mind, if you're aspiring for a web site eventually. I would expect to see more programs of this nature in the near future, begin to pop up alot with other hosts. Anyway.....my seismometers are "retired".....I'am "retired"... and now, html....is "retired". How about a retread job?-ha. Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Easiest web site construction I've seen Date: Tue, 06 Oct 1998 22:43:23 -0700 Hi All I was also trying to put together a web page. Has anyone got a comment/recommendation about Adobe pagemill or Claris pagemaker? I think those are the program names. I would like to avoid HTML text if possible. Thanks Barry >meredith lamb wrote: > >.... > One can make a web site using just the stuff they give you. Of > course it would be enhanced with any other accessories like > camera, scanner or whatnot..... > > The main drawback I have seen is that it seems to be toooo > popular, as, their can be trouble getting through on weekdays, > weekends seem to be the best time to play with the program, > or perhaps late at night. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Easiest web site construction I've seen Date: Wed, 07 Oct 1998 00:37:53 -0600 PSN- We used MS FrontPage'97 to make the Pymatuning EQ website: http://groundmotion.cr.usgs.gov/pym/pym.htm -Edward barry lotz wrote: > Hi All > I was also trying to put together a web page. Has anyone got a > comment/recommendation about Adobe pagemill or Claris pagemaker? I think > those are the program names. I would like to avoid HTML text if > possible. > Thanks > Barry > >meredith lamb wrote: > > > >.... > > One can make a web site using just the stuff they give you. Of > > course it would be enhanced with any other accessories like > > camera, scanner or whatnot..... > > > > The main drawback I have seen is that it seems to be toooo > > popular, as, their can be trouble getting through on weekdays, > > weekends seem to be the best time to play with the program, > > or perhaps late at night. > > > > _____________________________________________________________________ > > 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) From: John Hernlund Subject: Re: Easiest web site construction I've seen Date: Wed, 07 Oct 1998 09:29:41 -0700 (MST) I try to avoid using those fancy "WYSIWYG" web page makers, because there is more going on behind the scene than it seems. There is a html language war being waged by different groups and software developers. The war is market driven of course, as businesses push hard for more commerce-friendly software online. I have tried most of the programs out there, and what I found is that generally: - Some programs made pages that only worked well with certain browsers - The file size of pages made from these programs was >3X larger than mine - The programs stuck in tags, which I hate, and slip in their name - Their tag syntax for items like tables differ - Sometimes they re-size images for a default page format - They are often way overpriced! I guess I am a more old-fashioned web person, but I simply prefer the ability to telnet into a folder, make text changes, and leave fast. This saves me a lot of time. I can also work several times faster than web developers using programs like Pagemill. I also have a preference for future web page syntax; I would love to see it incorporate some items similar to TeX on unix... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ "It is easier to excuse an ignorant person who claims that theory is unnecessary and dispensable in his supposed practice, than to excuse a Sophist who concedes its value to the schools (as, perhaps, only a mental exercise) but who at the same time maintains that matters are quite different in practice- that as one leaves school to enter the world, one will realize one has been pursuing empty ideals and philosophical dreams- and, in a word, that what sounds good in theory is of no practical use." -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No Practical Use ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Greg Subject: Re: Easiest web site construction I've seen Date: Wed, 07 Oct 1998 17:42:03 +0000 I agree with what John H. wrote to some extent. If I had to choose a commercial program (buy one) right now, I think I'd look into Adobe Pagemill. Otherwise download (for FREE) Netscape Communicator Standard Edition, use Composer to write the page and clean it up a little by hand. Composer makes way too many tags for simple things. For example instead of a page break
sometimes it puts in
or something similar. It only makes a couple of meta tags and they are very easy to delete. One is worth keeping. It also does stuff like instead of , but they both still work. Also Composer does tend to resize images when you save the HTML. I usually correct that by hand. If you open the image in Netscape it will show the dimensions in the title bar. _________________ More on topic. I'm within weeks of buy Larry's ADC board, but I don't know about the pre-amp. I'd love to do the following (which I realize involves very little construction) 1. Get a brand new 4.5 Hz geophone and put it in a PVC pipe outside under ground a little. I'll be digging with a pick-axe if I get that far ;) I need some old work songs. 2. Put a small pre-amp in the tube with the geophone. One like Sean-Thomas uses (long battery life) 3. Convert the geophone output to fiber optic and run the fiber to the house. I want fiber optic because of lightning and the ability to extend the distance. 4. Covert back to copper at the back of the computer. I doubt all that will happen soon though. For starters I'll be using my surplus geophone from one of those $10 kits everyone bought. Maybe someday I'll finish my metal Lehman. I don't have any place to put it right now, so it doesn't matter too much. Aside from Larry's pre-amp board for the Lehmans, is there some pre-built amp that I could use for the geophone and just run the risk of lightning with copper? I don't want to have to run power to the geophone preamp AND data to the computer. With a lot more money I could probably run it with a solar panel, but... Also I'm pretty bad with a soldering iron. From the back of the computer to where I want to burry the geophone is about 20-30 ft. I can even move the computer a little closer to the wall if it would help. ,Greg _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re: Easiest web site construction I've seen Date: Wed, 7 Oct 1998 15:16:08 +0000 Hello Meridith and John Hernlund, I agree with John in his view that hand coding is best. Over the past several years and numerous sites under my belt, I personally prefer to hand code the pages. My way is the old-fashioned, 'cut-paste-upload-test/look' method. I load WSFTP (upload software), a favorite editor, I hack for awhile, upload file to my website, and look at it with my web-browser --live. Guidelines: 1 - use 800 x 600 resolution - many monitors are running this res, 2 - use a template, and hack that up, 3 - do not use tiny text, many people wear glasses, set the res for them --everybody will benefit, 4 - do not use frames, many people hate it, (is ok for catalogs) 5 - do not use fancy colors unless you test, test, and test 6 - use a spelling checker, and click & clack all of your links 7 - if you have many pictures, put them on multiple pages or better, make small clickable 'thumb-nail's and use them to load the larger pictures, more work, but infinately better, 8 - unless absolutely lossless pictures are required such as X-Ray pictures, use jpeg type compression schemes to help reduce picture size, 9 - if you want a saavy, cool site, include a TEXT-ONLY version for those folks who are using non-graphic terminals. Miscellany: 10 - include META TITLE for book-marking, 11 - include META SEARCH KEYWORDS for search engines 12 - include last modification date and your e-mail address 13 - lastly, test, test, and test. Some programs which I find are acceptable: Inprise (Borland) "IntraBuilder", HotMetal Pro (hotdog html coders choice) HotDog -- (self explanatory) Micr$oft -- FrontPage, "HTML for Dummies" was fair book on subject with lots of templates on CD. And of course, vector to NetScape for the authoratative InterNet Engineering Task Force (IETF) compliant web code tags. ---------- Shameless braggadacio....check out website Scot Stride & I made at: http://www.jpl.nasa.gov/mpfmir/rovercom/rovcom.html or mirror at: http://mars.sgi.com/rovercom/rovcom.html Best Wishes, Walt Williams, 98.10.07 dfheli@.............. ========================================================== ------- Forwarded Message Follows ------- Date: Wed, 07 Oct 1998 09:29:41 -0700 (MST) From: John Hernlund Subject: Re: Easiest web site construction I've seen To: PSN-L Mailing List Reply-to: PSN-L Mailing List I try to avoid using those fancy "WYSIWYG" web page makers, because there is more going on behind the scene than it seems. There is a html language war being waged by different groups and software developers. The war is market driven of course, as businesses push hard for more commerce-friendly software online. I have tried most of the programs out there, and what I found is that generally: - Some programs made pages that only worked well with certain browsers - The file size of pages made from these programs was >3X larger than mine - The programs stuck in tags, which I hate, and slip in their name - Their tag syntax for items like tables differ - Sometimes they re-size images for a default page format - They are often way overpriced! I guess I am a more old-fashioned web person, but I simply prefer the ability to telnet into a folder, make text changes, and leave fast. This saves me a lot of time. I can also work several times faster than web developers using programs like Pagemill. I also have a preference for future web page syntax; I would love to see it incorporate some items similar to TeX on unix... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ --->deletia<--- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rex Klopfenstein, Jr." Subject: Re: Seismometer Pictures Date: Wed, 07 Oct 1998 19:34:14 -0400 I have a question, are you using the fiberglass 'stuff' used to make air ducts for your covers? I am thinking about using the duct board as an outside cover and fill inside with several layers of foam board. The taped joints really seal out drafts and also improve the appeareance of the units. Where is your vault located? I just cut a door in my basement wall into an old cystern for a vault. It has a separate slap from the house so it is better than nothing! Now I have to clean up and paint the walls. I am planning to build a pier similar to Sean's example. I am currently machining the parts for two SG's for the E-W and N-S axis. When I get these finished with these, I'm planning build a VBB. Just starting to collect the materials and making drawings. meredith lamb wrote: > Too add to the days mix of photos, I just got done with some web > site construction of my own vault pictures. > http://www.geocities.com/ResearchTriangle/Facility/1739/vault.html > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: Easiest web site construction I've seen Date: Wed, 07 Oct 1998 18:00:52 -0600 Barry, Edward, Walt, John and Greg, Thanks for the feedback on web page makers. Seems like the heavy concensus is leaning toward Adobe Pagemill. They do have a free trial 15 day, version of it on their web site for download. http://www.adobe.com/prodindex/pagemill/demodnld.html (choice of power Macintosh or windows, but you need to fill out a form first). I went ahead and downloaded it (~14mb) plus their "getting started" manuel (~1.5mb). Briefly ran it, and in many ways its alot like the GeoBuilder program on GeoCities; but with alot more controls and choices, and explanations. One main positive is that it can be done offline, whereas GeoBuilder has ALOT to do online, and with my ISP, 20 minutes goes whipping by.....sometimes I can resume and sometimes I have to redo, if I get switched off. Too me, Netscape Composer book seems to presume that the reader already knows everything (which I don't). No outside unacqainted pre-edition suggestions readers I think. John.....liked your very extensive site...alot of great educational material there, along with alot of scenic Arizona pictures. Walt.... Yimminy Jeepers!...All those mars rover pictures that go on and on........mars exploration fans heaven! Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ralvarez@........ (Raul Alvarez) Subject: Re: Easiest web site construction I've seen Date: Wed, 7 Oct 1998 18:20:35 -0600 (MDT) Hi Meredith, Enjoyed your web page, but those COOKIES can drive you nuts. Does the geocities site allow you to turn them off? Probably not as they collect info for themselves. Raul >Hi all, > >Been using the http://www.geocities.com free web site deal >for acouple of weeks. What I have is mostly the "old" html code >approach. > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "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) From: meredith lamb Subject: Re: Seismometer Pictures Date: Wed, 07 Oct 1998 19:28:13 -0600 Rex Klopfenstein, Jr. wrote: > I have a question, are you using the fiberglass 'stuff' used to make air > ducts for your covers? I am thinking about using the duct board as an > outside cover and fill inside with several layers of foam board. The taped > joints really seal out drafts and also improve the appeareance of the units. No, on the two horizontals, I used the original Sprengnethers metal frames and simply covered them with layers of commercial "ReflexTex" aluminium/plastic/airbubbles insulation. I used 3M spray glue for attachment. The lower lining is surplus rubber strips to somewhat protect the insulation. However, on the vertical cover, I had to make my own frame cover. I just used peg board, aluminium angles, metal angle brackets, spray glue, 1 layer inside (with taped joints), and 2 layers outside. I salvaged the original round metal and glass viewing porthole (zero view), and stuck that on with bolts and nuts. The side closest to the viewer is actually the access "door", using drilled and tapped screws into the aluminum and pegboard substructure. Your idea of fiberglass could well work fine; but, perhaps you would still need a metal frame to connect too. > > > Where is your vault located? I just cut a door in my basement wall into an > old cystern for a vault. It has a separate slap from the house so it is > better than nothing! Now I have to clean up and paint the walls. I am > planning to build a pier similar to Sean's example. I am currently > machining the parts for two SG's for the E-W and N-S axis. When I get these > finished with these, I'm planning build a VBB. Just starting to collect the > materials and making drawings. > My vault is in the house's crawlspace corner. That way all I had to dowas build 2 short height addtional "walls", including the entrance in one. Ended up digging down an additional 6 inches, as the piers need to be more massive, and the seismometers covers needed room to lift off for servicing on the horizontals. Hope your cistern is large enough for the pier/s you may need. If not, your basement would probably work for any possible additions. Suggest thick plastic tarp underneath the piers to keep the water from being absorbed by your pier/s, and tilting stuff results/cycles. The S-G's you're building.... are you going to use Larry's capacitive sensor circuit amplifer and general size characteristics? Personally, my giant S-G's seem to work great, and the output seems to be a very close reflection of the output of the Sprengnethers horizontals; but with few short maintenance adjustments as the piers they're on, are alot smaller than the Sprengnether piers (which I need to fix), along with the throw on single styrafoam cover-ha. Good on the STM-8 VBB plans....the vertical is very important. I use my vertical as the trigger for the lot, as it doesn't show the closeby "Lawnmower quakes"-ha. Have fun... Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: Easiest web site construction I've seen Date: Wed, 07 Oct 1998 19:50:02 -0600 Raul Alvarez wrote: > Hi Meredith, > > Enjoyed your web page, but those COOKIES can drive you nuts. > Does the geocities site allow you to turn them off? Probably not > as they collect info for themselves. > > Raul > Raul, You got me there....I don't know about shutting off the "cookies". Have had experience with them with programs, but I guess overall, they don't really present too much of a problem, but, yes sometimes, they are a real nusiance....especially if ones in a hurry. So..... hows the seismograph progress going there, with or without the giant IBM voice coil magnets? Hope it is coming along. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Easiest web site construction I've seen Date: Wed, 07 Oct 1998 20:36:12 -0700 To All Also thanks for the feedback. I think I will create a page using a composer and then hand edit it. I like that Idea. Regards Barry Greg wrote: > > I agree with what John H. wrote to some extent. If I had to choose a > commercial program (buy one) right now, I think I'd look into Adobe > Pagemill. Otherwise download (for FREE) Netscape Communicator Standard > Edition, use Composer to write the page and clean it up a little by > hand. Composer makes way too many tags for simple things. For example > instead of a page break
sometimes it puts in >
or something similar. It only makes a couple of > meta tags and they are very easy to delete. One is worth keeping. It > also does stuff like > instead of , but they both still > work. Also Composer does tend to resize images when you save the HTML. I > usually correct that by hand. If you open the image in Netscape it will > show the dimensions in the title bar. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ralvarez@........ (Raul Alvarez) Subject: Re: Easiest web site construction I've seen Date: Thu, 8 Oct 1998 17:56:03 -0600 (MDT) >So..... hows the seismograph progress going there, with or >without the giant IBM voice coil magnets? Hope it is coming >along. > >Thanks, Meredith Lamb > Hi Meredith, Not a whole lot of progress since my last posting to my web site. (www.frii.com/~ralvarez). Been real busy with other things this summer, but looking towards snowed in days to work on it!! Won't be long here in the mountains. Raul ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "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) From: "Walt Williams" Subject: PSN-L: Website Construction Date: Thu, 8 Oct 1998 19:46:43 +0000 Hello Raul, I visited your website, you have an agressive agenda! I love the 2-meter antenna on your "solar page", very sexy. Cool security pictures. Good luck with your STM. Walt Williams, 98.10.08 dfheli@.............. http://www.pacificnet.net/~dfheli ------- Forwarded Message Follows ------- Date: Thu, 8 Oct 1998 17:56:03 -0600 (MDT) To: PSN-L Mailing List From: ralvarez@........ (Raul Alvarez) Subject: Re: Easiest web site construction I've seen Reply-to: PSN-L Mailing List >So..... hows the seismograph progress going there, with or >without the giant IBM voice coil magnets? Hope it is coming >along. > >Thanks, Meredith Lamb > Hi Meredith, Not a whole lot of progress since my last posting to my web site. (www.frii.com/~ralvarez). Been real busy with other things this summer, but looking towards snowed in days to work on it!! Won't be long here in the mountains. Raul ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "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) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: robert barns <75612.2635@..............> Subject: Pymatuning event Date: Fri, 9 Oct 1998 11:59:09 -0400 Why was the Ohio 'quake called "Pymatuning"? Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@.................. Subject: Re: Pymatuning event Date: Fri, 9 Oct 1998 10:34:02 -0600 (MDT) > > Why was the Ohio 'quake called "Pymatuning"? > Bob Barns > > _____________________________________________________________________ The location was just south of the south end of the Pymatuning reservoir, so Ed Cranswick et al. gave it that name. JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Pymatuning aftershock Date: Fri, 09 Oct 1998 15:16:55 -0600 Bob- Did you record the Pymatuning aftershock this morning? We have a link to the CERI records at the website: http://groundmotion.cr.usgs.gov/pym/pym.htm We have also included your records of the Pymatuning EQ and the Java teleseism at the website under 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) From: Roger Baker Subject: The Hi-Q Gravimeter/Seismograph Date: Fri, 09 Oct 1998 17:41:13 -0500 Friends,=20 I wish to proudly announce that I finally got a web page up and running that illustrates many of the details of construction of my gravimeter/seismograph design that I discussed on this list some months ago.= =20 This is one big, slow-loading, long-winded page with enough text, digital photos, drawings and charts to satisfy the most curious, I hope, and with a chart of what I believe is the 5.6 magnitude quake of 11:54 GMT off the coast of Nicaragua this morning along with charts from Albuquerque, N.M., and Hockley, Texas for comparison. To access the page use the following URL: http://www.eden.com/~rcbaker Then go to the VERY BOTTOM of my file index and click "yourpage.html" dated Oct. 9. This will slowly load the latest version from today (I haven't learned how to delete the older stuff from my server yet. Just learning!).= =20 And you bet your boots I would love to get any comments from this group, critical or otherwise. Below you will find the introduction to my page as text. --Yours, Roger Baker ************************************************************************ The Hi-Q Gravimeter/Seismometer This is an amateur scientist-friendly design for an inexpensive vertical seismometer and gravimeter, based on a high-Q magnetic spring combined with force feedback, using optical displacement detection, and all mounted within a magnetically shielded isothermal enclosure.=20 =A0 This instrument, which I call the "Hi-Q", will work as either a teleseismic vertical seismograph or as a gravimeter. Its virtues are that it is relatively small, inexpensive, and easy to build. My design utilizes a very high-Q magnetic spring suspension in combination with active magnetic feedback in an isothermal enclosure to give a frequency response that extends to DC, making it also suitable for use as a gravimeter, able to see the daily background fluctuations in earth tide.=20 The only real problem with a gravimeter being used as a seismometer is that seismometers are designed to be so sensitive to vertical acceleration that slow drift and earth tides are likely to throw the readings off scale. A seismometer usually looks for the smallest possible acceleration changes, Since gravity is physically the same as acceleration, gravimeters are merely versions of seismometers with an infinitely long period response. My instrument is capable of recording acceleration or gravitational data at a fixed location for long periods of time with minor adjustment. My instrument works to detect teleseismic events that match known events recorded by official seismic stations.=20 The principle that=A0 I use employs the repulsion and attraction between magnets as a spring force to balance the force of gravity. I prefer this approach to the metal springs more commonly used in vertical seismographs. Such high-Q systems, even with fairly short periods, are an excellent match for force feedback, because the low mechanical losses associated with high-Q systems imply that they can efficiently capture kinetic energy over periods of time much longer than their own natural frequency. This are the basic virtue needed to sense slow teleseismic events with a physically small instrument.=20 My Hi-Q is fine-tuned to remain within its proper range, i.e. to keep the sensor output from going off-scale, by shifting the position of a ceramic magnet placed on top of the instrument. This is possible because the nickel alloy shield together with a large iron pipe which surrounds the both the instrument and the isothermal enclosure does not shield it completely from external magnetic influence. However, this double shield seems to be sufficient to prevent most practical problems arising from ambient magnetic field changes.=20 The Hi-Q is designed to operate from a small three amp, 12 VDC power supply. Most of the power actually goes to supply the resistance heater needed to maintain a constant temperature set just above ambient or room temperature inside the Styrofoam insulation enclosure. The entire seismograph feedback circuit by itself requires very little power. Since ceramic magnets such as those I use for the magnetic suspension are decidedly sensitive to temperature, my design must remain at a carefully controlled constant temperature. This can be easily done with good thermal insulation and a simple feedback thermistor/ temperature regulation circuit.= =20 Since both temperature control and magnetic shielding are necessary, my experimental designs have evolved in the direction of using a short stubby beam pivoting on a horizontal knife edge that can both be contained within a vertical nickel alloy magnetic shield tube 2.5 inches in diameter and 8 inches tall surrounded by the Styrofoam insulation enclosure.=20 =A0I anticipate the basic materials, exclusive of the magnetic shield and external electronics (mostly off the shelf from Radio Shack), to cost no more than about $25. Since everything is relatively small, it could also be sealed against barometric changes by hermetically sealing it inside a glass container at near atmospheric pressure.=20 I have also made progress in building a more miniaturized version of the instrument only about an inch in diameter, which appears to be nearer in its response characteristics to a geophone, but which remains sensitive to static displacements. The latter instrument is similar to the Hi-Q but smaller, and can be made to fit in a 6 inch tall section of iron pipe, 1.5 inch ID. Such a configuration is very compact and, with suitable adjustments, can be used at any angle from the vertical. My thinking is that the latter design is small enough so that these could be tilted at about a 45 degree angle and mounted in a common isothermal enclosure for full three axis recording with one instrument. For example, four of these could be aligned along the edges of a four-sided pyramid, and the outputs from opposite pairs of outputs added in such a way as to be able to calculate quake shocks as three-dimensional vectors of acceleration force. With computing power being relatively cheap, this should be practical.=20 *************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: The Hi-Q Gravimeter/Seismograph Date: Fri, 09 Oct 1998 21:29:44 -0600 Roger Baker, Congratulations on your new web site! Looks like one heck of a lot of work on your part. Magnificent mechanical drawing! Do suggest that the text be black instead of blue; kind of hard to read. (I also have Netscape) Its going to take awhile to read.......but.....in the meantime...... thanks for the huge data! Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: The Hi-Q Gravimeter/Seismograph Date: Fri, 09 Oct 1998 21:59:38 -0700 Roger, I too, want to congratulate you on your site. And I too have to mirror Meredith=92s comment about the text. My old eyes have a hard time readin= g the light blue on black (Netscape 4.06 at work and 4.04 at home). Additionally, when I printed out the pages at work, the photos came through great on a B&W HP5SI at 600 dpi, but the text prints out in gray, making it hard to read on paper too. Keep up the good work, Charles R. Patton _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Re: The Hi-Q Gravimeter/Seismograph Date: Sat, 10 Oct 1998 01:13:39 -0500 OK OK, I hear you guys. I wanted something to set off the photos a little and black is great for that at least. Since the text is long, maybe I'll try black on pale green or something easy on the eyes like that. Meanwhil= e, I think you can go to the edit button on the browser toolbar and down to "select all" and then dump it in a text file like Word. Details, details.= ... Meanwhile, what I want most is for somebody to get curious enough to replicate and improve the thing now that they can see that it exists and probably does work, and is fairly easy to build, and so on. But thats mostly behind me now; the next personal challenge is all the other instruments that need designing and building. I have years of good stuff that it would be neat to put up on a Science Hacker web page. Like how to gold plate the surface of water, to mention one interesting phenomenon I discovered a few years back, plus lots of others... --Yours, Roger =20 =20 *************************************************************************= * At 09:59 PM 10/9/98 -0700, you wrote: >Roger, >I too, want to congratulate you on your site. And I too have to mirror >Meredith=92s comment about the text. My old eyes have a hard time readi= ng >the light blue on black (Netscape 4.06 at work and 4.04 at home). >Additionally, when I printed out the pages at work, the photos came >through great on a B&W HP5SI at 600 dpi, but the text prints out in >gray, making it hard to read on paper too. > >Keep up the good work, >Charles R. Patton > > > >_____________________________________________________________________ > >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) From: GeE777@....... Subject: Re: The Hi-Q Gravimeter/Seismograph Date: Sat, 10 Oct 1998 12:39:02 EDT Hi Roger and All I have built a gravitymeter using a vertical geophone. The geophone has the same equipment that a gravity meter has, a mass, the coil, suspended on a spring. I applied a voltage to the geophone coil to deflect the coil till the coil hit the stop at the end of the coil travel space. An electronic switch removes the voltage from the coil and hooks the coil output to a recording device, a digital oscillascope. The coil, returning to its natural at rest position, outputs a pulse. The voltage of that pulse is determined by the distance the coil travels within the geophone magnetic field to the at rest position. If the gravity is greater. the coil will be at rest lower in the coil travel area. If the voltage raises the coil to the top of the travel area, the resulting pulse will be larger. To make it more sensitive, I applied an opposite polarity voltage to the coul to deflect it to the lower stop. With more gravity, the resulting pulse will be lower voltage. I then subtract this pulse from the pulse caused by the coil deflected up I have recorded earth tides with this device. Temperature sensitive? yes! I have been hand calculating the temperature effects out of the results. I am building a gravitymeter using four geophones, two connected to the output in the opposite polarity to reduce the effect of seismic noise. This model is almost ready for testing. George Erich Seismic Exploration Acquisition Consultant P. O. Box 2011, Norwalk, CA 90650, U. S. A. Phone (562) 868-6013 e-mail GeE777@....... 33 53.90N 118 04.53W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bzimmerman@............ Subject: Re: Pymatuning aftershock Date: Sat, 10 Oct 1998 13:02:15 -0500 (EST) Edward: No, I did not record the Pymatuning aftershock here in Edinboro. I spoke with Nano Seeber who thought it looked like about an M1 event. I would not expect to pick up an event that small considering I am about 50 km from the epicenter. Guess its time to start thinking about some more sophisticated equipment. Thanks for posting those records. On Fri, 9 Oct 1998, Edward Cranswick wrote: Brian Zimmerman > Did you record the Pymatuning aftershock this morning? We have a > link to the CERI records at the website: > > http://groundmotion.cr.usgs.gov/pym/pym.htm > > We have also included your records of the Pymatuning EQ and the Java > teleseism at the website under 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 > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: LARGE QUAKE NOW Date: Mon, 12 Oct 1998 12:00:43 +1200 00:50 UTC 12 Oct 98 recording very large anplitude long period waves in Dunedin NZ 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) From: "Francesco" Subject: R: LARGE QUAKE NOW Date: Mon, 12 Oct 1998 01:07:54 +0100 Until now, no signal from Italy stations. Francesco _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: A Gravity meter using 4 Geophones Date: Sun, 11 Oct 1998 18:24:52 -0600 GeE777@....... wrote: > I have recorded earth tides with this device. Temperature sensitive? yes! I > have been hand calculating the temperature effects out of the results. I am > building a gravitymeter using four geophones, two connected to the output in > the opposite polarity to reduce the effect of seismic noise. This model is > almost ready for testing. > > George Erich > George Erich, I'd be very interested to hear/see more results of your combined 4 geophone instrument. What brand, frequency are you using? Seems like I recall Larry Cochrane using 2 geophones with a type of comparator electronics for regular seismic monitoring. Anyway, I hope the results are positive and its possible for you to submit the details somehow, sometime. Thanks for the new stuff! -- Meredith Lamb <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> Main Web site: http://www.users.uswest.net/~psnseismograph52/Index.html and secondary site: http://www.geocities.com/ResearchTriangle/Facility/1739/index.html <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re large quake Date: Mon, 12 Oct 1998 12:36:50 +1200 00:50 UTC 12 Oct 98 recording very large anplitude long period waves >in Dunedin NZ >Dave Update ....... lookes like the quake is between me and antartica, and prob closer to me. The aslwww seismogram from Scott Base Antartica shows the best record and an early estimate of the event size is between M5.5 and M6.0 this puts the quake within 1500 km odd of me the geophones didnt show it but strong low freq S and Surface waves on my recorder indicate that its probably a shallow event ie. 33km or less. It appeares to have been followed by an aftershock some 15 minutes later 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) From: GeE777@....... Subject: Re: A Gravity meter using 4 Geophones Date: Sun, 11 Oct 1998 21:29:15 EDT Hello All One thing I failed to mention if someone wants to try this. When the voltage to deflect the coil is removed there is a strong short spike resulting from the emf collapsing around the coil. You don't want this as it is much stronger than the wavelet generated by the coil coming to rest. The electronic switch closed the circuit between the coil and the recording device after the spike and before the wavelet generated by the coil movement. To reduce errors, level the phone carefully and always keep on the same azimuth. I got 10 HZ phones But would like to try 4.5 HZ. In a message dated 10/11/98 5:31:31 PM Pacific Daylight Time, psnseismograph52@.......... writes: << I'd be very interested to hear/see more results of your combined 4 geophone instrument. What brand, frequency are you using? >> George Erich Seismic Exploration Acquisition Consultant P. O. Box 2011, Norwalk, CA 90650, U. S. A. Phone (562) 868-6013 e-mail GeE777@....... 33 53.90N 118 04.53W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: A Gravity meter using 4 Geophones Date: Sun, 11 Oct 1998 18:50:01 -0700 (MST) George, Excellent device!!! How accurate is it? milligals or microgals? What if you wanted to build a nanogal gravimeter? Do such things exist? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ "It is easier to excuse an ignorant person who claims that theory is unnecessary and dispensable in his supposed practice, than to excuse a Sophist who concedes its value to the schools (as, perhaps, only a mental exercise) but who at the same time maintains that matters are quite different in practice- that as one leaves school to enter the world, one will realize one has been pursuing empty ideals and philosophical dreams- and, in a word, that what sounds good in theory is of no practical use." -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No Practical Use ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Re large quake Date: Sun, 11 Oct 1998 19:17:02 -0700 Dave I picked up moderate waves in California foothills @ 00:20:18 UTC also Barry David A. Nelson wrote: > > 00:50 UTC 12 Oct 98 recording very large anplitude long period waves > >in Dunedin NZ > >Dave > > Update ....... > > lookes like the quake is between me and antartica, and prob closer to me. > The aslwww seismogram from Scott Base Antartica shows the best record > and an early estimate of the event size is between M5.5 and M6.0 > > this puts the quake within 1500 km odd of me the geophones didnt show it > but strong low freq S and Surface waves on my recorder indicate that > its probably a shallow event ie. 33km or less. > > It appeares to have been followed by an aftershock some 15 minutes later > > Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "J. D. Cooley" Subject: Re: Re large quake Date: Sun, 11 Oct 1998 20:22:40 -0700 Recent automated solutions from the International Data Centre: B Date Time Lat Lon Nph Depth Mag Region a 1998/10/12 00:28:49.0 18.31N 145.82E 7 267.2 mb 3.4 Mariana Islands a 1998/10/11 23:57:30.3 56.21S 143.31W 13 mb 4.7 Pacific-Antarctic Ridge a 1998/10/11 23:36:24.6 56.76S 142.77W 11 mb 4.7 Pacific-Antarctic Ridge a 1998/10/11 21:45:22.4 27.38S 62.55W 8 mb 4.7 Santiago Del Estero Prov., Arg. a 1998/10/11 21:43:13.8 27.72S 63.69W 16 mb 5.6 Santiago Del Estero Prov., Arg. I don't see the Mb5.6 on the aslwww seismograms, but certainly see the Pacific-Antarctic Ridge. At 07:17 PM 10/11/98 -0700, you wrote: >Dave > I picked up moderate waves in California foothills @ 00:20:18 UTC >also > Barry > > >David A. Nelson wrote: >> >> 00:50 UTC 12 Oct 98 recording very large anplitude long period waves >> >in Dunedin NZ >> >Dave >> >> Update ....... >> >> lookes like the quake is between me and antartica, and prob closer to me. >> The aslwww seismogram from Scott Base Antartica shows the best record >> and an early estimate of the event size is between M5.5 and M6.0 >> >> this puts the quake within 1500 km odd of me the geophones didnt show it >> but strong low freq S and Surface waves on my recorder indicate that >> its probably a shallow event ie. 33km or less. >> >> It appeares to have been followed by an aftershock some 15 minutes later >> >> Dave > >_____________________________________________________________________ > >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) From: barry lotz Subject: Red Puma Date: Sun, 11 Oct 1998 21:00:35 -0700 I lost the bookmark. Could someone pass it to me? Thanks Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: peaches@............ (Donna Whitaker) Subject: Re: Red Puma Date: Sun, 11 Oct 1998 18:12:15 -1000 (HST) Barry, http://seismo.ethz.ch/redpuma/redpuma_ami_list.html >I lost the bookmark. Could someone pass it to me? > Thanks > 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) From: meredith lamb Subject: Re: Red Puma Date: Sun, 11 Oct 1998 22:11:00 -0600 barry lotz wrote: > I lost the bookmark. Could someone pass it to me? > Thanks > Barry > http://seismo.ethz.ch/redpuma/redpuma-ami-list.html Use_ where- is shown. -- Meredith Lamb <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> Main Web site: http://www.users.uswest.net/~psnseismograph52/Index.html and secondary site: http://www.geocities.com/ResearchTriangle/Facility/1739/index.html <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>  

barry lotz wrote:

I lost the bookmark. Could someone pass it to me?
                    &nb sp;                    &nbs p; Thanks
                    &nb sp;                    &nbs p;   Barry
 
http://seismo.ethz.ch/redpuma/redpuma-ami-list.html
Use_ where- is shown.

--
Meredith Lamb
<><><><><><><><><><><><><><><><><><><><><><><><>< ;><><><><><><><><><><><>
Main Web site:  http://www.users.uswest.net/~psnsei smograph52/Index.html
                    &nb sp;         and secondary site:
   http://www.geocities.com/Research Triangle/Facility/1739/index.html
<><><><><><><><><><><><><><><><><><><><><><><><>< ;><><><><><><><><><><><>
  From: barry lotz Subject: Re: Red Puma Date: Sun, 11 Oct 1998 21:23:47 -0700 Thanks much! Barry >Donna Whitaker wrote: > > Barry, > > http://seismo.ethz.ch/redpuma/redpuma_ami_list.html > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: A Gravity meter using 4 Geophones Date: Mon, 12 Oct 1998 05:34:51 EDT Hi John & All I started experimenting with this in my lab just before my retirement. Then I was called away to another job. I know that everything seemed to interfere with my results. Movement, rotating, etc. In a message dated 10/11/98 6:51:01 PM Pacific Daylight Time, hernlund@....... writes: << George, Excellent device!!! How accurate is it? milligals or microgals? What if you wanted to build a nanogal gravimeter? Do such things exist? >> <> George Erich Seismic Exploration Acquisition Consultant P. O. Box 2011, Norwalk, CA 90650, U. S. A. Phone (562) 868-6013 e-mail GeE777@....... 33 53.90N 118 04.53W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "J. D. Cooley" Subject: Large quake Date: Mon, 12 Oct 1998 05:02:08 -0700 It is interesting that the quake that occurred at approx. 23:50 UTC on 10/11/98 has not been reported by any agency (except the IDC) even though it has been over 12 hours now! I realize that the guys/gals at USGS are in bed, but usually there are a few automated, at least, solutions posted to RedPuma with a quake this size. Just observing! "JD" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Large quake Date: Tue, 13 Oct 1998 07:18:54 +1200 At 05:02 AM 10/12/98 -0700, you wrote: >It is interesting that the quake that occurred at approx. 23:50 UTC on >10/11/98 has not been reported by any agency (except the IDC) even though it has been over 12 hours now! >I realize that the guys/gals at USGS are in bed, but usually there are a few >automated, at least, solutions posted to RedPuma with a quake this size. >Just observing! >"JD" yeah !!! its common for that to happen wit h quakes in my part of the world. there are many M5-M6 and a reasonable munber of M6++ events that NEVER show up on the NEIC listings. I find it frustrating but as there is nothing i can do abt it i jst live with it. Yesterday's event that u speak of worked out to be ~Ms5.8 + - 0.2 as recorded on my SDR system. i apologise for the time error i reported yesterday too, i was 1 hr in advance, we jst changed to daylite time and i looked at the wrong clock (smile) my i hate daylight saving time !! 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) From: S-T Morrissey Subject: Gravimeters Date: Mon, 12 Oct 1998 18:31:04 -0500 (CDT) Re: high resolution gravimeters The most recent commercial gravimeters have nanogal resolution at about 1/nanodollar prices. Some are absolute meters, the more clever of which tracks a falling corner cube reflector with a lasar interferometer to measure the acceleration of G. It is curious to "hear" it "plink" away while at work, as a little elevator device raises the cube in the vacuum column and drops it repeatedly about every 10 seconds. The lasar interferometer uses a reference mass on a "superspring" in the base to eliminate seismic disturbances. A computer does the statistics in real time, as well as correcting for environmental noise (temperature, etc.) After about 24 hours, sub-microgal noise levels are realized. For reference, earth tides are of the order of 100 to 200 microgals, where a microgal is an acceleration of 10^-8 m/sec^2. The instrument costs in excess of $100k. The highest resolution instruments levitate a superconducting sphere to measure G. A combination of magnetic and electrostatic feedback make detection levels of less than 1 nanogal (10^-11 m/sec^2) possible, with noise level power spectra of 10^-3 microgal^2 per cycle/hour possible at periods longer than 0.2 cycle/hour. With these instruments, many natural effects have to be removed, including the solid earth tides, ocean loading, barometric loading (0.3 microgal/millibar), etc. More affordable instruments are realized by incorporating electrostatic feedback into LaCoste-style instruments. Even the best Broadband vertical seismometer, the STS-1V, produces earth-tide data with microgal resolution, and its ultra long period seismic data is useful for studying the gravitational oscillations of the earth excited by large earthquakes. At the IRIS stations, the 24-bit digitizer resolution of the ULP data (at 150 seconds) is about 100 counts / microgal. The long period (20 to 60 second) surface waves produced by moderate (M=6 +) quakes are often about the amplitude of the earth tides. at 150 seconds. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Large quake Date: Mon, 12 Oct 1998 17:35:04 -0700 (MST) On Tue, 13 Oct 1998, David A. Nelson wrote: > >I realize that the guys/gals at USGS are in bed, but usually there are a few > >automated, at least, solutions posted to RedPuma with a quake this size. > yeah !!! its common for that to happen wit h quakes in my part of the > world. there are many M5-M6 and a reasonable munber of M6++ events that > NEVER show up on the NEIC listings. I find it frustrating but as there is > nothing i can do abt it i jst live with it. This worries me, because I like to work with statistical analysis of seismicity, which depends very strongly on the accuracy, thoroughness, and coverage of the collected data. But, like you said, we get what we get... > Yesterday's event that u speak of worked out to be ~Ms5.8 + - 0.2 as > recorded on my SDR system. We all need more stations all over the globe to improve coverage. It would be nice to have as many stations as would be needed so that no magnitude 2.0 or greater event would escape detection anywhere... But we are probably talking mega-bucks here... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ http://www.public.asu.edu/~hernlund/ "It is easier to excuse an ignorant person who claims that theory is unnecessary and dispensable in his supposed practice, than to excuse a Sophist who concedes its value to the schools (as, perhaps, only a mental exercise) but who at the same time maintains that matters are quite different in practice- that as one leaves school to enter the world, one will realize one has been pursuing empty ideals and philosophical dreams- and, in a word, that what sounds good in theory is of no practical use." -Immanuel Kant, On the Proverb: That May be True in Theory, But Is of No Practical Use ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: Geophone amps Date: Mon, 12 Oct 1998 19:41:46 -0500 (CDT) Greg, The micropower seismic preamp that we use here (I assume you saw my description of it, which I can repeat if necessary) has been made here and elsewhere, and was also made by Sprengnether at one time. I think they still make a pre-amp, but I don't know if it is micro-power. (www.sprengnether.com). The amplifier is simple enough that it can even be made on a perforated PC board in a few hours with just two MC1776 Amps, but using fixed gain/filter stages for simplicity and be able to run from photo-lithium batteries for a few years. I guess I could just do it and document it if there is any interest. The battery operation greatly simplifies the remote installation. I actually have several versions of the 4 amplifier design that were made by students on perf-board to fit inside the 1" diameter case of hydrophones (we once tried to detect tidal strains by using an air-gun in a well and timing the seismic pulse to stations several kilometers away). Maybe I should photograph the board and post it with documentation. The only consideration for use with a geophone is that more gain will be needed. We use 60 db (x 1000) and up with a L4-C with a 100v/m/sec pad. A geophone may need 10x more gain. The pre-amp can be configured for 80db, or x100 per stage, Its filters can also be made low pass at 1 hz or less to provide more response to distant earthquakes. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: Large quake Date: Mon, 12 Oct 1998 19:54:23 -0500 (CDT) In the defense of the USGS, I don't think that they have recently missed cataloging any magnitude 6 earthquake. The NEIS HAS listed the events near the Pacific-Antartic ridge of Oct. 11, at magnitudes 5.7 and 5.5, as well as a rare event this morning near the Artic circle, a M=4.8 north of Severnaya Zemlya. I believe that their current global catalogue is quite complete for events greater than magnitude 5. On the other hand, the earth could still use better coverage with calibrated broadband stations, which is where the PSN can make a serious scientific contribution. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Large quake Date: Tue, 13 Oct 1998 14:28:11 +1200 At 07:54 PM 10/12/98 -0500, you wrote: >In the defense of the USGS, I don't think that they have recently missed >cataloging any magnitude 6 earthquake. The NEIS HAS listed the events >near the Pacific-Antartic ridge of Oct. 11, at magnitudes 5.7 and >5.5, as well as a rare event this morning near the Artic circle, >a M=4.8 north of Severnaya Zemlya. I believe that their current >global catalogue is quite complete for events greater than magnitude 5. >On the other hand, the earth could still use better coverage with >calibrated broadband stations, which is where the PSN can make a >serious scientific contribution. >Regards, >Sean-Thomas Sorry Sean i have to STRONGLY dispute that as said in my previous e-mail there are many M5 - M6 and the occassional M6+ event in this part of the world that goes unnoticed. i could produce quite a substantial list of these events over even the last 10 yrs since i have been seriously involved in seismic recording. here is one example that didnt make it to the NEIC listing..... 210498 1134 6.3 39.02S 174.92E, 245KD, 33 km WSW of Taumarunui, Felt from Christchurch to Taranaki and Hawke's Bay. Shaking felt for about 45 seconds in Wellington (New Zealand) the only M6+ event onland in NZ so far this yr and it was missed IDC did log it but at a ridiculously low magnitude and very poor location now there have been at least 5 x M5.0 + events this yr alone that didnt make it to the NEIC d/m/y NZST Mb Lat Long Depth 090298 0626 5.3 45.06S 170.47E, 12KD, 250298 0517 5.4 41.92S 174.19E, 21KD, 250398 2018 5.0 38.29S 176.29E, 05KD, 060598 2056 5.0 44.91S 167.97E, 33KD, 140598 2127 5.0 38.47S 177.17E, 58KD, now this isnt all the NEIC's fault, from observations... the NZ seismo observatory dont seem to get the info passed on to the USA agencies very well. WHY ?? i dont know jst seems to be a lack of communications. im jst an amateur *smile* 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) From: Edward Cranswick Subject: Re: Large quake Date: Mon, 12 Oct 1998 21:07:40 -0600 Thank you, Sean-Thomas. S-T Morrissey wrote: > In the defense of the USGS, I don't think that they have recently missed > cataloging any magnitude 6 earthquake. The NEIS HAS listed the events > near the Pacific-Antartic ridge of Oct. 11, at magnitudes 5.7 and > 5.5, as well as a rare event this morning near the Artic circle, > a M=4.8 north of Severnaya Zemlya. I believe that their current > global catalogue is quite complete for events greater than magnitude 5. > > On the other hand, the earth could still use better coverage with > calibrated broadband stations, which is where the PSN can make a > serious scientific contribution. > > 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 -- 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) From: Edward Cranswick Subject: Re: Large quake Date: Mon, 12 Oct 1998 21:14:09 -0600 Dave- Interesting observations. I'll pass them along. -Edward David A. Nelson wrote: > At 07:54 PM 10/12/98 -0500, you wrote: > >In the defense of the USGS, I don't think that they have recently missed > >cataloging any magnitude 6 earthquake. The NEIS HAS listed the events > >near the Pacific-Antartic ridge of Oct. 11, at magnitudes 5.7 and > >5.5, as well as a rare event this morning near the Artic circle, > >a M=4.8 north of Severnaya Zemlya. I believe that their current > >global catalogue is quite complete for events greater than magnitude 5. > >On the other hand, the earth could still use better coverage with > >calibrated broadband stations, which is where the PSN can make a > >serious scientific contribution. > >Regards, > >Sean-Thomas > > Sorry Sean i have to STRONGLY dispute that as said in my previous > e-mail there are many M5 - M6 and the occassional M6+ event in this part > of the world that goes unnoticed. > > i could produce quite a substantial list of these events over even the > last 10 yrs since i have been seriously involved in seismic recording. > > here is one example that didnt make it to the NEIC listing..... > > 210498 1134 6.3 39.02S 174.92E, 245KD, 33 km WSW of Taumarunui, Felt > from Christchurch to Taranaki and Hawke's Bay. Shaking felt for about 45 > seconds in Wellington (New Zealand) > > the only M6+ event onland in NZ so far this yr and it was missed > IDC did log it but at a ridiculously low magnitude and very poor location > > now there have been at least 5 x M5.0 + events this yr alone that > didnt make it to the NEIC > > d/m/y NZST Mb Lat Long Depth > 090298 0626 5.3 45.06S 170.47E, 12KD, > 250298 0517 5.4 41.92S 174.19E, 21KD, > 250398 2018 5.0 38.29S 176.29E, 05KD, > 060598 2056 5.0 44.91S 167.97E, 33KD, > 140598 2127 5.0 38.47S 177.17E, 58KD, > > now this isnt all the NEIC's fault, from observations... the NZ > seismo observatory dont seem to get the info passed on to the USA > agencies very well. WHY ?? i dont know jst seems to be a lack of > communications. > im jst an amateur *smile* > > 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 -- 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) From: "James M Hannon" Subject: Re: Large quake Date: Tue, 13 Oct 1998 07:26:57 -0500 That explains why I was confused. I looked at my watch and thought either my watch was set wrong or you had discovered a new way to predict quakes :)! Jim Hannon "David A. Nelson" on 10/12/98 02:18:54 PM Please respond to PSN-L Mailing List To: PSN-L Mailing List cc: Subject: Re: Large quake i apologise for the time error i reported yesterday too, i was 1 hr in advance, we jst changed to daylite time and i looked at the wrong clock (smile) my i hate daylight saving time !! Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. _____________________________________________________________________ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "J. D. Cooley" Subject: Re: Large quake Date: Tue, 13 Oct 1998 06:39:27 -0700 At 02:28 PM 10/13/98 +1200, you wrote: [good sized snip] > >here is one example that didnt make it to the NEIC listing..... > >210498 1134 6.3 39.02S 174.92E, 245KD, 33 km WSW of Taumarunui, Felt >from Christchurch to Taranaki and Hawke's Bay. Shaking felt for about 45 >seconds in Wellington (New Zealand) The University of Washington (IRIS) has data and some very impressive seismograms of a quake occurring on (using your convention for date): 200498 23:34:13.0 38.31S 173.8E 245KD M5.5 Could this be the quake you are referring to? I don't know if the USGS has it in any of their listings, but the most impressive seismogram of this quake was by CTAO which is listed as: Charters Towers, Queensland, Australia and below that is: IRIS-USGS. It also says that this seismometer is on the BRS Network which is the University of Queensland, Brisbane, Australia. I didn't check the other quakes you listed below, just the one. "JD" > > the only M6+ event onland in NZ so far this yr and it was missed > IDC did log it but at a ridiculously low magnitude and very poor location > > now there have been at least 5 x M5.0 + events this yr alone that >didnt make it to the NEIC > >d/m/y NZST Mb Lat Long Depth >090298