Subject: Fw: Further eruptions, lava flowage and tsunami at Stromboli. From: "Erich Kern" efkern@............. Date: Tue, 31 Dec 2002 17:43:57 -0800 -----Original Message----- From: Dan Shackelford [mailto:danshack@.............. Sent: Tuesday, December 31, 2002 4:48 PM To: gvn@............... mayberry@.............. Subject: Further eruptions, lava flowage and tsunami at Stromboli. Following the strong explosion and lava flow production of 28 December at Stromboli, the lava flows appeared to cease moving that day. However, by 30 December the lava flowage down the Sciara del Fuoco had resumed, although at a slower rate than that of the 28th. At 1325 on the 30th there was another strong explosion with a large amount of ash. A small tsunami also occurred, likely the result of the collapse of part of the lava fields on the Sciara del Fuoco (perhaps more than the lava flows collapsed, it is unclear.). About 6 people were injured by the tsunami. There have been voluntary evacuations from the island. Source: http://www.educeth.ch/stromboli/beso/bes02c-en.html 31 December 2002, 8.30 Update: The tsunami phenomenon, which yesterday we defined "small" in order to avoid useless alarms when news were still very confusing and contradictory, has revealed hour after hour all its severity. The greatest damages were recorded in Ginostra, but also in the village of Stromboli many boats were destroyed or taken away by the waves, and many buildings were damaged. At least 3 tourists are reported injured, and other sources talk of 6 injured in total. The tsunami has reached also the other Eolian islands and Milazzo harbour, where 2 tankers suffered difficulties. During the evening, following the invitation of the Civil Defense, tens of inhabitants and tourists voluntarily left the island. Moreover, since this morning NON-RESIDENT PEOPLE ARE NOT ALLOWED TO LAND ON STROMBOLI. For what concerns the dynamics of the phenomenon producing the tsunami, there are no evidences of summit eplosions, but only of the collapse, as we suggested yesterday, of part of the lava field over the steep slope of the Sciara del Fuoco, that may have detached only by gravitational instability. This hypothesis is supported by the observation, yesterday afternoon, of a big scar at about midslope on the Sciara (source: the volcano guides Antonio Famularo and Nino Zerilli) and by the seismic data recorded by INGV - Catania, which show the presence of two non-volcanic seismic events, at 13:15 and 13:22 local time respectively. 30 December 2002, 14:55 Update: The village of Stromboli is currently without power supply, probably because of a fault in the power engine, located close to the coast. First damages to walls and buildings near the coast are reported, due to the tsunami wave. Moreover, new ash-rich explosions are reported near the Sciara, which suggests new interactions between magma and seawater. A new survey of Civil Defense and INGV is currently in progress. 30 December 2002, 13.45 Update: A new, strong, explosion, observed at about 13:25 local time, has ejected a great amount of ash that is now falling, mixed with rain, over the village of Stromboli. The explosion must have caused a collapse of part of the lava flow deposits (or more) along the Sciara del Fuoco, as a small tsunami was observed all along the coast near the villages, from Ficogrande (up to the road) to Scari (up to the helipad). Also in Ginostra boats were moved by the tsunami in the small harbour. The explosion was apparently not so loud, and no earthquake was felt by the population. 30. December 2002, 11.00 Update: According to the Stromboli volcano guides, and in particular to Antonio Famularo, the lava flows resumed their movement after a pause, although slower than the first day. The flows seem to originate from a (new? different?) fissure, at about 800 m, below the NE crater. The flows still reach the sea, producing a smaller amount of vapour with respect to the beginning of the eruption. The lack of visibility at the top still prevents observers from evaluating the level of strombolian activity at the craters during the lava effusion. 28. December 2002 Abbreviated from report by Sonia Calvari, Istituto Nazionale di Geofisica e Vulcanologia, via VOLCANO listserv: "On 28 December the height of ejecta reached 200 m above NE Crater, and the shape of explosions suggested magma very close to the crater rim. This activity climaxed at 18:30 with a strong explosion that caused ash fallout on the village of Stromboli, accompanied by the opening of an eruptive fissure trending NE-SW. The fissure opened at the NE base of NE Crater. A lava flow came out from the base of the fissure, and formed three lava branches spreading within the Sciara del Fuoco. Within 30 minutes the flows reached the sea, about 1 km away. The lava flows were up to 300 m wide at the shore line, but very narrow along the steep slope of Sciara del Fuoco. A thermal survey carried out from helicopter on 29 December did not allow us to see the craters because of poor weather conditions. A thick cloud was covering the summit of the volcano above 600 m a.s.l. The lava flows below this elevation were cooling and did not show any movement, suggesting the end of the effusive phase. Photos are on the INGV-CT web page." o o o o o o o o > > > > > danshack@............. o _____________________________ o _____ | | .][__n_n_|DD[ ====_____ | | >(________|__|_[_________]_|___________________________| _/oo OOOOO oo` ooo ooo 'o!o!o o!o!o` -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re. Seismometer Distance Transducer From: ChrisAtUpw@....... Date: Wed, 1 Jan 2003 14:00:11 EST Hi all seis experimenters, John Lahr has very kindly put my notes on the LVDT precision seismic sensor Kit on his Website at: http://jjlahr.com/science/psn/chapman/lvdt/ Th introductory notes now include three close up Webcam photos of the sensor and board. Click on any photo to get an enlarged image. The Experimental notes include details of the modifications to reduce the sensor noise and to greatly extend the period, with circuit diagrams and components lists. I have been able to achieve a resolution of about +/-7 nano metres and a sensor movement range of >+/-12 mm with this Kit. I am developing additional LVDT applications circuits with inexpensive sensors similar to those used by Sean Morrissey on his vertical STM-8 and also with capacitative sensor plates. I will publish them in due course. The NE5521 LVDT chip seems to be easy to use and to be capable of excellent performance. Please also look at my notes on Meredith's Website http://geocities.com/meredithlamb/ Regards, Chris Chapman Hi all seis experimenters,

     John Lahr has very kindly put my notes on the LVDT precision seismic sensor Kit on his Website at:
http://jjlahr.com/science/psn/chapman/lvdt/

     Th introductory notes now include three close up Webcam photos of the sensor and board. Click on any photo to get an enlarged image.

     The Experimental notes include details of the modifications to reduce the sensor noise and to greatly extend the period, with circuit diagrams and components lists. I have been able to achieve a resolution of about +/-7 nano metres and a sensor movement range of >+/-12 mm with this Kit.

     I am developing additional LVDT applications circuits with inexpensive sensors similar to those used by Sean Morrissey on his vertical STM-8 and also with capacitative sensor plates. I will publish them in due course. The NE5521 LVDT chip seems to be easy to use and to be capable of excellent performance.

     Please also look at my notes on Meredith's Website http://geocities.com/meredithlamb/

     Regards,

     Chris Chapman Subject: Re: Re. Seismometer Distance Transducer From: meredithlamb meredithlamb@............. Date: Wed, 01 Jan 2003 15:33:55 -0700 Hi Chris and all, Although I've not had any actual experience with LVDT's and their circuits; it appears that your reference to the NE design and/or your modifications look to be very highly encouraging for their use in more precision instrumentation by amateurs. Thanks for all the work you've done!!! I'd hazard to guess that with such, one might find a really reasonably low priced sensor and accurate assembly that has been not really obtainable heretofore! About the only question of a general nature, I can find to ask is that regarding the shielding of the LVDT unit. Roughly, what do you use; or would suggest in either the minimum or maximum sense? Would say, specific shielding surrounding the LVDT board itself might be in itself somewhat adequate; as alot of amateur seismo's are often rather huge? Take care, Meredith Lamb ChrisAtUpw@....... wrote: > Hi all seis experimenters, > > John Lahr has very kindly put my notes on the LVDT precision > seismic sensor Kit on his Website at: > http://jjlahr.com/science/psn/chapman/lvdt/ > > clipped...... Hi Chris and all,

Although I've not had any actual experience with LVDT's and their
circuits; it appears that your reference to the NE design and/or
your modifications look to be very highly encouraging for their
use in more precision instrumentation by amateurs.  Thanks for
all the work you've done!!!  I'd hazard to guess that with such,
one might find a really reasonably low priced sensor and
accurate assembly that has been not really obtainable heretofore!

About the only question of a general nature, I can find to ask
is that regarding the shielding of the LVDT unit.  Roughly, what
do you use; or would suggest in either the minimum or maximum
sense?  Would say, specific shielding surrounding  the LVDT
board itself might be in itself somewhat adequate; as alot of
amateur seismo's are often rather huge?

Take care, Meredith Lamb

ChrisAtUpw@....... wrote:

Hi all seis experimenters,

     John Lahr has very kindly put my notes on the LVDT precision seismic sensor Kit on his Website at:
http://jjlahr.com/science/psn/chapman/lvdt/

clipped......

Subject: Re: Re. Seismometer Distance Transducer From: ChrisAtUpw@....... Date: Wed, 1 Jan 2003 22:09:51 EST In a message dated 01/01/2003, meredithlamb@............. writes: > About the only question of a general nature, I can find to ask is that > regarding the shielding of the LVDT unit. Roughly, what do you use; or > would suggest in either the minimum or maximum sense? Would say, specific > shielding surrounding the LVDT board itself might be in itself somewhat > adequate; as a lot of amateur seismo's are often rather huge? Take care, > Meredith Lamb ChrisAtUpw@....... wrote: > > >> Hi all seis experimenters, John Lahr has very kindly put my notes on the >> LVDT precision seismic sensor Kit on his Website at: >> http://jjlahr.com/science/psn/chapman/lvdt/ Hi Meredith, The circuit is most sensitive to alternating magnetic fields with a frequency harmonically related to the oscillator frequency. Screens of Al or preferably tinplate are effective. It is preferable to make them with >6 cm clearance from the ends of the board. If they are closer and can physically move, they can couple to the sensor field and give a false reading. I checked the overall frequency response of the sensor by fixing a single 1" square of thick copper wire to the shaft of a miniature electric motor. I mounted the loop about an inch from the outer end of one sensor coil and varied the rotational rate of the motor to modulate the magnetic field. The simplest way to check for interference is to wedge the ferrite rod armature and check that the output signal is constant. The only interference source that I experienced was due to the computer monitor several feet from the sensor. Trimming the oscillator frequency removed the problem, additional screening was a bonus. This sensitivity is only a problem if you don't know about it. Regards, Chris Chapman In a message dated 01/01/2003, meredithlamb@............. writes:

About the only question of a general nature, I can find to ask is that regarding the shielding of the LVDT unit.  Roughly, what do you use; or would suggest in either the minimum or maximum sense?  Would say, specific shielding surrounding the LVDT board itself might be in itself somewhat adequate; as a lot of amateur seismo's are often rather huge? Take care, Meredith Lamb


ChrisAtUpw@....... wrote:

Hi all seis experimenters, John Lahr has very kindly put my notes on the LVDT precision seismic sensor Kit on his Website at:
http://jjlahr.com/science/psn/chapman/lvdt/


Hi Meredith,

     The circuit is most sensitive to alternating magnetic fields with a frequency harmonically related to the oscillator frequency. Screens of Al or preferably tinplate are effective. It is preferable to make them with >6 cm clearance from the ends of the board. If they are closer and can physically move, they can couple to the sensor field and give a false reading. I checked the overall frequency response of the sensor by fixing a single 1" square of thick copper wire to the shaft of a miniature electric motor. I mounted the loop about an inch from the outer end of one sensor coil and varied the rotational rate of the motor to modulate the magnetic field. 
     The simplest way to check for interference is to wedge the ferrite rod armature and check that the output signal is constant. The only interference source that I experienced was due to the computer monitor several feet from the sensor. Trimming the oscillator frequency removed the problem, additional screening was a bonus. This sensitivity is only a problem if you don't know about it.

     Regards,

     Chris Chapman Subject: RE: Notes to UK--Nick From: Jack Ivey ivey@.......... Date: Thu, 2 Jan 2003 09:33:24 -0500 Mauro, I'm not sure it will be _very_ sensitive to axial movements. Horizontal movements of the magnet will not cause as much change in magnetic flux linkage through the coil as vertical movements because of the geometry of the coil and magnet. For movement in one horizontal direction, the magnet is moving parallel to the wires at the top of the coil. For the other horizontal direction, the magnet is moving parallel to the flux between it's poles. In either case any flux change through the coil is a second order effect due to curvature of the coil and curvature of the magnet path. For vertical movement the flux change is a first order effect, proportional to displacement. As a guess I would expect the horizontal sensitivity to be 5x to 10x down from the vertical. Jack -----Original Message----- From: Mauro Mariotti [mailto:mariotti@.......... Sent: Monday, December 30, 2002 2:01 PM To: psn-l@.............. Subject: Re: Notes to UK--Nick Hi all, I suggest a different approach for homemade vertical sensors. The sensor in the link you propose is VERY sensitive to axial movements (horizontal movements) if you give a look to http://www.infoeq.it/doc02v_e.htm and scroll the page until you reach: Lacoste suspension sensor you can see a good approach to a sensitive long period seismometer. There are also sofisticated tecniques to have a virtually infinite response for that kind of seismometer using a "zero length spring". Mr Lacoste writed a lot of paper on it. Chris Chapman is better documented on this point. I hope to have the time to publish an abstract on these tecnmiques but any clever mind can understand how the Lacoste suspension is great and simple to build. Regards Mauro ----- Original Message ----- From: John & Jan Lahr To: psn-l@.............. Sent: Monday, December 30, 2002 6:47 PM Subject: Re: Notes to UK--Nick I've scanned Jim's Short Period design plans and put a copy on my web site here: http://jjlahr.com/science/psn/lehman/ This will save on postage and make the plans available to more people. They are a good example of how to document a seismic sensor design. Happy New Year, John At 12:15 PM 12/28/2002, you wrote: Nick--I do not need an e-mail address. I only needed your mailing address to send the "Short Period" design plans. The plans were mailed airmail to U.K. 2 days before Christmas. A good New Year to you and all the PSN group. J. Lehman.
Mauro,
I'm not sure it will be _very_ sensitive to axial movements.  Horizontal
movements of the magnet will not cause as much change in magnetic
flux linkage through the coil as vertical movements because of the geometry
of the coil and magnet.  For movement in one horizontal direction, the magnet
is moving parallel to the wires at the top of the coil.  For the other horizontal
direction, the magnet is moving parallel to the flux between it's poles.  In either
case any flux change through the coil is a second order effect due to curvature
of the coil and curvature of the magnet path.  For vertical movement the flux
change is a first order effect, proportional to displacement.  As a guess I
would expect the horizontal sensitivity to be 5x to 10x down from the vertical. 
 
Jack
-----Original Message-----
From: Mauro Mariotti [mailto:mariotti@..........
Sent: Monday, December 30, 2002 2:01 PM
To: psn-l@..............
Subject: Re: Notes to UK--Nick

Hi all,
I suggest a different approach for homemade vertical sensors.
The sensor in the link you propose is VERY sensitive to axial movements
(horizontal movements)
if you give a look to
 
http://www.infoeq.it/doc02v_e.htm
 
and scroll the page until you reach:
 
Lacoste suspension sensor
 
you can see a good approach to a sensitive
long period seismometer.
 
There are also sofisticated tecniques to
have a virtually infinite response for that kind
of seismometer using a "zero length spring".
 
Mr Lacoste writed a lot of paper on it.
Chris Chapman is better documented on this point.
I hope to have the time to publish an abstract on these tecnmiques
but any clever mind can understand how the Lacoste suspension
is great and simple to build.
 
Regards
Mauro
 
 
 
----- Original Message -----
Sent: Monday, December 30, 2002 6:47 PM
Subject: Re: Notes to UK--Nick

I've scanned Jim's Short Period design plans and put a copy on my web site here:
http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more people.  They
are a good example of how to document a seismic sensor design.

Happy New Year,
John



At 12:15 PM 12/28/2002, you wrote:
Nick--I do not need an e-mail address.  I only needed your mailing address to send the "Short Period" design plans.
   The plans were mailed airmail  to U.K. 2 days before Christmas.
   A good New Year to you and all the PSN group.
                              J. Lehman.
Subject: Re: Notes to UK--Nick From: "Mauro Mariotti" mariotti@......... Date: Thu, 2 Jan 2003 16:15:35 +0100 Hi, yes, I am gree. The simple design of the lacoste suspension should be considered instead of a simple vertical spring. I experimented several solution and i what i learned the Lacoste suspension is the easier and better solution for a homemade design. Anyway the interesting life of seismo-amateurs is the=20 ability to experiments many solutions... so all the ideas are always welcome! regards Mauro ----- Original Message -----=20 From: Jack Ivey=20 To: psn-l@................. Sent: Thursday, January 02, 2003 3:33 PM Subject: RE: Notes to UK--Nick Mauro, I'm not sure it will be _very_ sensitive to axial movements. = Horizontal movements of the magnet will not cause as much change in magnetic=20 flux linkage through the coil as vertical movements because of the = geometry of the coil and magnet. For movement in one horizontal direction, the = magnet is moving parallel to the wires at the top of the coil. For the other = horizontal direction, the magnet is moving parallel to the flux between it's = poles. In either case any flux change through the coil is a second order effect due to = curvature of the coil and curvature of the magnet path. For vertical movement = the flux=20 change is a first order effect, proportional to displacement. As a = guess I=20 would expect the horizontal sensitivity to be 5x to 10x down from the = vertical. =20 Jack -----Original Message----- From: Mauro Mariotti [mailto:mariotti@.......... Sent: Monday, December 30, 2002 2:01 PM To: psn-l@.............. Subject: Re: Notes to UK--Nick Hi all, I suggest a different approach for homemade vertical sensors. The sensor in the link you propose is VERY sensitive to axial = movements (horizontal movements) if you give a look to=20 http://www.infoeq.it/doc02v_e.htm=20 and scroll the page until you reach: Lacoste suspension sensor=20 you can see a good approach to a sensitive=20 long period seismometer. There are also sofisticated tecniques to=20 have a virtually infinite response for that kind of seismometer using a "zero length spring". Mr Lacoste writed a lot of paper on it. Chris Chapman is better documented on this point. I hope to have the time to publish an abstract on these tecnmiques but any clever mind can understand how the Lacoste suspension is great and simple to build. Regards Mauro ----- Original Message -----=20 From: John & Jan Lahr=20 To: psn-l@................. Sent: Monday, December 30, 2002 6:47 PM Subject: Re: Notes to UK--Nick I've scanned Jim's Short Period design plans and put a copy on my = web site here: http://jjlahr.com/science/psn/lehman/ This will save on postage and make the plans available to more = people. They are a good example of how to document a seismic sensor design. Happy New Year, John At 12:15 PM 12/28/2002, you wrote: Nick--I do not need an e-mail address. I only needed your = mailing address to send the "Short Period" design plans. The plans were mailed airmail to U.K. 2 days before = Christmas. A good New Year to you and all the PSN group. J. Lehman.
Hi,
yes, I am gree.
The simple design of the lacoste = suspension should=20 be
considered instead of a simple vertical = spring.
I experimented several solution and i = what i=20 learned
the Lacoste suspension is the easier = and better=20 solution
for a homemade design.
 
Anyway the interesting life of = seismo-amateurs is=20 the
ability to experiments many=20 solutions...
so all the ideas are always = welcome!
 
regards
Mauro
----- Original Message -----
From:=20 Jack = Ivey
To: psn-l@..............
Sent: Thursday, January 02, = 2003 3:33=20 PM
Subject: RE: Notes to = UK--Nick

Mauro,
I'm=20 not sure it will be _very_ sensitive to axial movements. =20 Horizontal
movements of the magnet will not cause as much change in = magnetic=20
flux=20 linkage through the coil as vertical movements because of the = geometry
of=20 the coil and magnet.  For movement in one horizontal = direction,=20 the magnet
is moving parallel to the wires at the = top of=20 the coil.  For the other=20 horizontal
direction, the magnet is moving parallel to = the flux=20 between it's poles.  In = either
case any flux change through the coil is a = second=20 order effect due to curvature
of the coil and curvature of the magnet=20 path.  For vertical=20 movement the flux=20
change is a first order effect, = proportional to=20 displacement.  As a=20 guess I=20
would expect = the horizontal=20 sensitivity to be 5x to 10x down = from the=20 vertical. 
 
Jack
-----Original Message-----
From: Mauro Mariotti=20 [mailto:mariotti@..........
Sent: Monday, December 30, = 2002 2:01=20 PM
To: psn-l@..............
Subject: Re: Notes = to=20 UK--Nick

Hi all,
I suggest a different approach = for homemade=20 vertical sensors.
The sensor in the link you = propose is VERY=20 sensitive to axial movements
(horizontal = movements)
if you give a = look to=20
 
http://www.infoeq.it/doc02v_e.= htm=20
 
and scroll the page until you=20 reach:
 
Lacoste suspension = sensor=20
 
you can see a good approach to a = sensitive=20
long period = seismometer.
 
There are also sofisticated = tecniques to=20
have a virtually infinite = response for that=20 kind
of seismometer using a "zero = length=20 spring".
 
Mr Lacoste writed a lot of paper = on=20 it.
Chris Chapman is better = documented on this=20 point.
I hope to have the time to = publish an=20 abstract on these tecnmiques
but any clever mind can = understand how the=20 Lacoste suspension
is great and simple to = build.
 
Regards
Mauro
 
 
 
----- Original Message ----- =
From:=20 John = & Jan=20 Lahr
To: psn-l@.............. =
Sent: Monday, December 30, = 2002 6:47=20 PM
Subject: Re: Notes to = UK--Nick

I've scanned Jim's Short Period design plans and = put a copy=20 on my web site here:
http://jjlahr.com/science/psn/lehman/
This = will=20 save on postage and make the plans available to more people.  = They
are a good example of how to document a seismic sensor=20 design.

Happy New Year,
John



At 12:15 PM=20 12/28/2002, you wrote:
Nick--I do not=20 need an e-mail address.  I only needed your mailing address = to send=20 the "Short Period" design plans.
   The=20 plans were mailed airmail  to U.K. 2 days before=20 Christmas.
   A good New Year = to you=20 and all the PSN group.
          &nbs= p;            = ;      =20 J.=20 Lehman.
= Subject: Re: Notes to UK--Nick From: ChrisAtUpw@....... Date: Thu, 2 Jan 2003 19:19:06 EST In a message dated 02/01/2003, ivey@.......... writes: > Mauro, > I'm not sure it will be _very_ sensitive to axial movements. Horizontal > movements of the magnet will not cause as much change in magnetic flux > linkage through the coil as vertical movements because of the geometry of > the coil and magnet. For movement in one horizontal direction, the magnet > is moving parallel to the wires at the top of the coil. For the other > horizontal direction, the magnet is moving parallel to the flux between > it's poles. In either case any flux change through the coil is a second > order effect due to curvature of the coil and curvature of the magnet path. > For vertical movement the flux change is a first order effect, > proportional to displacement. As a guess I would expect the horizontal > sensitivity to be 5x to 10x down from the vertical. > Jack Hi Jack, I am in agreement with your analysis so far as it goes, but it seems to be incomplete and the conclusion may not be correct. The magnetic damping is presumably adjusted to be near critical for vertical motion. This should also give reasonably good damping for horizontal motion in the plane of the plate. However, the plate will be only lightly damped for horizontal oscillations perpendicular to it's plane and it will show a resonant characteristic with enhanced swing amplitudes. The magnetic field is highly inhomogeneous and movements of the magnet in this plane can be expected to give significant induced signals. The sensitivity could be decreased by mounting the magnet and sensor coil at right angles to the original orientation shown. An arrangement which is less sensitive to horizontal motion and can give a larger signal, may be made using a horizontally mounted flat coil with a vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2" long magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The end of the polepiece should be about the centre plane of the coil. A suitable coil would be about 3/8" long and 5/8" internal diameter, wound with 3,000 to 5,000 turns. Neodymium magnets type #31 or #39 are capable of giving very high damping forces, probably at considerably less cost than the 100 lb pull damping magnets in the original design. I use two opposed #31s with a small 1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong cheap magnets readily available, we might as well make use of them. Regards, Chris Chapman > >> From: Mauro Mariotti [mailto:mariotti@.......... >> Sent: Monday, December 30, 2002 2:01 PM >> Subject: Re: Notes to UK--Nick >> Hi all, >> I suggest a different approach for homemade vertical sensors. The sensor >> in the link you propose is VERY sensitive to axial movements >> (horizontal movements) if you give a look to >> http://www.infoeq.it/doc02v_e.htm >> and scroll the page until you reach: >> Lacoste suspension sensor >> you can see a good approach to a sensitive long period seismometer. >> ....... >> Regards Mauro >> >> >>> From: John & Jan Lahr >>> I've scanned Jim's Short Period design plans and put a copy on my web >>> site here: http://jjlahr.com/science/psn/lehman/ >>> This will save on postage and make the plans available to more people. >>> They >>> are a good example of how to document a seismic sensor design. In a message dated 02/01/2003, ivey@.......... writes:

Mauro,
I'm not sure it will be _very_ sensitive to axial movements.  Horizontal movements of the magnet will not cause as much change in magnetic flux linkage through the coil as vertical movements because of the geometry of the coil and magnet.  For movement in one horizontal direction, the magnet is moving parallel to the wires at the top of the coil.  For the other horizontal direction, the magnet is moving parallel to the flux between it's poles.  In either case any flux change through the coil is a second order effect due to curvature of the coil and curvature of the magnet path.  For vertical movement the flux change is a first order effect, proportional to displacement.  As a guess I would expect the horizontal sensitivity to be 5x to 10x down from the vertical. 
Jack


Hi Jack,

     I am in agreement with your analysis so far as it goes, but it seems to be incomplete and the conclusion may not be correct. The magnetic damping is presumably adjusted to be near critical for vertical motion. This should also give reasonably good damping for horizontal motion in the plane of the plate. However, the plate will be only lightly damped for horizontal oscillations perpendicular to it's plane and it will show a resonant characteristic with enhanced swing amplitudes. The magnetic field is highly inhomogeneous and movements of the magnet in this plane can be expected to give significant induced signals. The sensitivity could be decreased by mounting the magnet and sensor coil at right angles to the original orientation shown.

     An arrangement which is less sensitive to horizontal motion and can give a larger signal, may be made using a horizontally mounted flat coil with a vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2" long magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The end of the polepiece should be about the centre plane of the coil. A suitable coil would be about 3/8" long and 5/8" internal diameter, wound with 3,000 to 5,000 turns.

     Neodymium magnets type #31 or #39 are capable of giving very high damping forces, probably at considerably less cost than the 100 lb pull damping magnets in the original design. I use two opposed #31s with a small 1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong cheap magnets readily available, we might as well make use of them.

     Regards,

     Chris Chapman

From: Mauro Mariotti [mailto:mariotti@..........
Sent: Monday, December 30, 2002 2:01 PM
Subject: Re: Notes to UK--Nick
Hi all,
I suggest a different approach for homemade vertical sensors. The sensor in the link you propose is VERY sensitive to axial movements
(horizontal movements) if you give a look to
http://www.infoeq.it/doc02v_e.htm 
and scroll the page until you reach:
Lacoste suspension sensor
you can see a good approach to a sensitive long period seismometer.
........
Regards Mauro

From: John & Jan Lahr
I've scanned Jim's Short Period design plans and put a copy on my web site here: http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more people.  They
are a good example of how to document a seismic sensor design.


 Subject: RE: Notes to UK--Nick From: Jack Ivey ivey@.......... Date: Fri, 3 Jan 2003 09:01:08 -0500 Chris, Good point about the lack of damping in one horizontal direction. Mauro's web page shows a trace from a similar arrangement which shows this (long tail of low amplitude oscillation after the earthquake signal). I like the symmetry of your suggested coil setup, but I'm not sure changing the coil orientation will fix the problem completely though. There would still be undamped motion on one horizontal axis and still would be some sensitivity of the coil/magnet to horizontal motion, although maybe less than before. If a horizontal damping plate with a vertically aligned magnetic field were added it would help. The Wood-Anderson seismometers had a similar problem with the torsion wire "twanging" and solved it with a drop of oil around the wire as a damper. Jack -----Original Message----- From: ChrisAtUpw@....... [mailto:ChrisAtUpw@........ Sent: Thursday, January 02, 2003 7:19 PM To: psn-l@.............. Subject: Re: Notes to UK--Nick In a message dated 02/01/2003, ivey@.......... writes: Mauro, I'm not sure it will be _very_ sensitive to axial movements. Horizontal movements of the magnet will not cause as much change in magnetic flux linkage through the coil as vertical movements because of the geometry of the coil and magnet. For movement in one horizontal direction, the magnet is moving parallel to the wires at the top of the coil. For the other horizontal direction, the magnet is moving parallel to the flux between it's poles. In either case any flux change through the coil is a second order effect due to curvature of the coil and curvature of the magnet path. For vertical movement the flux change is a first order effect, proportional to displacement. As a guess I would expect the horizontal sensitivity to be 5x to 10x down from the vertical. Jack Hi Jack, I am in agreement with your analysis so far as it goes, but it seems to be incomplete and the conclusion may not be correct. The magnetic damping is presumably adjusted to be near critical for vertical motion. This should also give reasonably good damping for horizontal motion in the plane of the plate. However, the plate will be only lightly damped for horizontal oscillations perpendicular to it's plane and it will show a resonant characteristic with enhanced swing amplitudes. The magnetic field is highly inhomogeneous and movements of the magnet in this plane can be expected to give significant induced signals. The sensitivity could be decreased by mounting the magnet and sensor coil at right angles to the original orientation shown. An arrangement which is less sensitive to horizontal motion and can give a larger signal, may be made using a horizontally mounted flat coil with a vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2" long magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The end of the polepiece should be about the centre plane of the coil. A suitable coil would be about 3/8" long and 5/8" internal diameter, wound with 3,000 to 5,000 turns. Neodymium magnets type #31 or #39 are capable of giving very high damping forces, probably at considerably less cost than the 100 lb pull damping magnets in the original design. I use two opposed #31s with a small 1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong cheap magnets readily available, we might as well make use of them. Regards, Chris Chapman From: Mauro Mariotti [mailto:mariotti@.......... Sent: Monday, December 30, 2002 2:01 PM Subject: Re: Notes to UK--Nick Hi all, I suggest a different approach for homemade vertical sensors. The sensor in the link you propose is VERY sensitive to axial movements (horizontal movements) if you give a look to http://www.infoeq.it/doc02v_e.htm and scroll the page until you reach: Lacoste suspension sensor you can see a good approach to a sensitive long period seismometer. ........ Regards Mauro From: John & Jan Lahr I've scanned Jim's Short Period design plans and put a copy on my web site here: http://jjlahr.com/science/psn/lehman/ This will save on postage and make the plans available to more people. They are a good example of how to document a seismic sensor design.
Chris,
Good point about the lack of damping in one horizontal direction.  Mauro's
web page shows a trace from a similar arrangement which shows
this (long tail of low amplitude oscillation after the earthquake signal). 
 
I like the symmetry of your suggested coil setup, but I'm not sure 
changing the coil orientation will fix the problem completely though.  There
would still be undamped motion on one horizontal axis and still would be
some sensitivity of the coil/magnet to horizontal motion, although maybe
less than before. 
 
If a horizontal damping plate with a vertically aligned magnetic field were
added it would help.  The Wood-Anderson seismometers had a similar
problem with the torsion wire "twanging" and solved it with a drop of oil
around the wire as a damper.
 
Jack
 
-----Original Message-----
From: ChrisAtUpw@....... [mailto:ChrisAtUpw@........
Sent: Thursday, January 02, 2003 7:19 PM
To: psn-l@..............
Subject: Re: Notes to UK--Nick

In a message dated 02/01/2003, ivey@.......... writes:
Mauro,
I'm not sure it will be _very_ sensitive to axial movements.  Horizontal movements of the magnet will not cause as much change in magnetic flux linkage through the coil as vertical movements because of the geometry of the coil and magnet.  For movement in one horizontal direction, the magnet is moving parallel to the wires at the top of the coil.  For the other horizontal direction, the magnet is moving parallel to the flux between it's poles.  In either case any flux change through the coil is a second order effect due to curvature of the coil and curvature of the magnet path.  For vertical movement the flux change is a first order effect, proportional to displacement.  As a guess I would expect the horizontal sensitivity to be 5x to 10x down from the vertical. 
Jack


Hi Jack,

     I am in agreement with your analysis so far as it goes, but it seems to be incomplete and the conclusion may not be correct. The magnetic damping is presumably adjusted to be near critical for vertical motion. This should also give reasonably good damping for horizontal motion in the plane of the plate. However, the plate will be only lightly damped for horizontal oscillations perpendicular to it's plane and it will show a resonant characteristic with enhanced swing amplitudes. The magnetic field is highly inhomogeneous and movements of the magnet in this plane can be expected to give significant induced signals. The sensitivity could be decreased by mounting the magnet and sensor coil at right angles to the original orientation shown.

     An arrangement which is less sensitive to horizontal motion and can give a larger signal, may be made using a horizontally mounted flat coil with a vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2" long magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The end of the polepiece should be about the centre plane of the coil. A suitable coil would be about 3/8" long and 5/8" internal diameter, wound with 3,000 to 5,000 turns.

     Neodymium magnets type #31 or #39 are capable of giving very high damping forces, probably at considerably less cost than the 100 lb pull damping magnets in the original design. I use two opposed #31s with a small 1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong cheap magnets readily available, we might as well make use of them.

     Regards,

     Chris Chapman

From: Mauro Mariotti [mailto:mariotti@..........
Sent: Monday, December 30, 2002 2:01 PM
Subject: Re: Notes to UK--Nick
Hi all,
I suggest a different approach for homemade vertical sensors. The sensor in the link you propose is VERY sensitive to axial movements
(horizontal movements) if you give a look to
http://www.infoeq.it/doc02v_e.htm 
and scroll the page until you reach:
Lacoste suspension sensor
you can see a good approach to a sensitive long period seismometer.
.......
Regards Mauro

From: John & Jan Lahr
I've scanned Jim's Short Period design plans and put a copy on my web site here: http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more people.  They
are a good example of how to document a seismic sensor design.


Subject: Re: Graphite Levetation Devices From: "Connie and Jim Lehman" lehmancj@........... Date: Mon, 6 Jan 2003 22:38:16 -0500 Thanks Meredith for the summary of efforts at applying diamagnetic = levitation techniques to seismic sensor possibilities. =20 I first saw a demonstration of diamagnetic levitation several = summers ago in a Physics meeting. Later the details of that = demonstration was published in the Dec. 2001, The Physics Teacher. We = promptly built one from the recommended design, and were pleased at the = ease of adjustment to achieve levitation. =20 To go from a simple demonstration to a stable seismic sensor is a = challenge your summary addresses. I am still digesting the breadth of = the article. Best wishes to all working on this quest.. = Jim Lehman
Thanks Meredith for = the summary=20 of efforts at applying diamagnetic levitation techniques to seismic = sensor=20 possibilities. 
    I = first saw a=20 demonstration of diamagnetic levitation several summers ago in a Physics = meeting.  Later the details of that demonstration was = published in the=20 Dec. 2001, The Physics Teacher.  We promptly built one from=20 the recommended design, and were pleased at the ease of adjustment = to=20 achieve levitation. 
    To = go from a=20 simple demonstration to a stable seismic sensor is a challenge your = summary=20 addresses.  I am still digesting the breadth of the article.  = Best=20 wishes to all working on this quest..
          &nbs= p;            = ;            =             &= nbsp;           &n= bsp;           &nb= sp;           =20 Jim Lehman
Subject: Re: Graphite Levitation Devices From: meredithlamb meredithlamb@............. Date: Mon, 06 Jan 2003 23:41:54 -0700 Hi Jim, Thanks for the reference to the excellent illustrated pictures, text and references of the Adobe PDF article; "Small Inexpensive Diamagnetic Levitation Apparatus", at: http://www.aapt.org/tpt/pdf/dec01/apparatus_dec01.pdf It reminds me of the same type of mechanisms I used some time back; even down to the same general hardware. The current effort of several individuals is with levitating certain varieties of graphite as the mass itself; a dramatic switch in the roles of the basic material in the article above. Levitating magnets just presents too much susceptibility to magnetic "noise", for much useful seismometer utilization. Using levitated graphite as a recording working seimometer has already been done by David Lamb and James Spottiswoode. There is more examples, text, and pictures of this approach on John Lahr's very extensive and educational website, for those interested. See: http://www.jjlahr.com/science/physics/maglev/seismo/index.html Thanks for the best wishes! Its been a rather "unknown", but via the individual personal findings and discoveries of the fine people involved, the exploration challenge is more fun than work. Take care, Meredith Connie and Jim Lehman wrote: > Thanks Meredith for the summary of efforts at applying diamagnetic > levitation techniques to seismic sensor possibilities. I first saw > a demonstration of diamagnetic levitation several summers ago in a > Physics meeting. Later the details of that demonstration was > published in the Dec. 2001, The Physics Teacher. We promptly built > one from the recommended design, and were pleased at the ease of > adjustment to achieve levitation. To go from a simple demonstration > to a stable seismic sensor is a challenge your summary addresses. I > am still digesting the breadth of the article. Best wishes to all > working on this > quest.. > Jim Lehman Hi Jim,

Thanks for the reference to the excellent illustrated pictures,
text and references of the Adobe PDF article; "Small Inexpensive
Diamagnetic Levitation Apparatus", at:

http://www.aapt.org/tpt/pdf/dec01/apparatus_dec01.pdf

It reminds me of the same type of mechanisms I used some
time back; even down to the same general hardware.  The
current effort of several individuals is with levitating certain
varieties of graphite as the mass itself; a dramatic switch in the
roles of the basic material in the article above.  Levitating magnets
just presents too much susceptibility to magnetic "noise", for much
useful seismometer utilization.  Using levitated graphite as a recording
working seimometer has already been done by David Lamb and
James Spottiswoode.

There is more examples, text, and pictures of this approach on
John Lahr's very extensive and educational website, for those
interested.   See:

http://www.jjlahr.com/science/physics/maglev/seismo/index.html

Thanks for the best wishes!  Its been a rather "unknown", but
via the individual personal findings and discoveries of the fine
people involved, the exploration challenge is more fun than work.

Take care, Meredith
 

Connie and Jim Lehman wrote:

Thanks Meredith for the summary of efforts at applying diamagnetic levitation techniques to seismic sensor possibilities.    I first saw a demonstration of diamagnetic levitation several summers ago in a Physics meeting.  Later the details of that demonstration was published in the Dec. 2001, The Physics Teacher.  We promptly built one from the recommended design, and were pleased at the ease of adjustment to achieve levitation.    To go from a simple demonstration to a stable seismic sensor is a challenge your summary addresses.  I am still digesting the breadth of the article.  Best wishes to all working on this quest..                                                                                    Jim Lehman
Subject: Volcan Baru Array Update From: "a.rodriguez" stuff@................. Date: Thu, 9 Jan 2003 12:55:10 -0500 Hello Everyone, Happy New Year! I have done some updates to the array site. It includes the work done today. The eight bases are in place, within a few centimeters. Trenches next. http://www.volcanbaru.com/array/array.html All comments wanted and welcome. -- Best regards, angel mailto:angel@.............. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ebay item From: BOB BARNS royb1@........... Date: Fri, 10 Jan 2003 14:01:20 -0500 Hi, gang, Ebay.com has an item which may be of interest. Item # 3106334236 Ends Jan-15-03 15:51:29 PST "This auction is for a United Electro Dynamics Type DR 273 seismograph/drum recorder. The unit has three servo motor driver pens which write on a rotating lead screw driven drum in a continuous chart from the top of the chart to the bottom." This is three large drums on the same shaft. Beware of the $95 crating charge. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: rockland filter From: BOB BARNS royb1@........... Date: Fri, 10 Jan 2003 14:12:32 -0500 Hi gang, Another ebay item-- ROCKLAND WAVETEK 1042F DUAL HI LO FILTER Item # 3104911183 Ends Jan-13-03 09:56:12 PST These things are great with a seismograph, I use a 1022F which is v. similar. The manual should be avail. from Wavetek. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ebay item From: Raul Alvarez ralvarez@........ Date: Fri, 10 Jan 2003 13:22:43 -0700 Bob and group, Be VERY AWARE that the "Packing charge" is in ADDITION to the "Shipping charge" !!!!!! RA BOB BARNS wrote: > Hi, gang, >Ebay.com has an item which may be of interest. > Item # 3106334236 Ends Jan-15-03 15:51:29 PST >"This auction is for a United Electro Dynamics Type DR 273 >seismograph/drum recorder. The unit has three servo motor driver pens >which write on a rotating lead screw driven drum in a continuous chart >from the top of the chart to the bottom." > This is three large drums on the same shaft. >Beware of the $95 crating charge. >Bob Barns >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ebay item From: meredithlamb meredithlamb@............. Date: Fri, 10 Jan 2003 13:29:40 -0700 Hi Bob and all, Nice of you to notify of seismo items Bob! For this item, one might note that none of the pens are attached to the pen motors. The original pens (likely were a heated stylus) are probably hard to get and/or VERY expensive even "if" available. Alternatively one might find/make ink pens, but it would also be very difficult to do/find. The total item may have been a parts salvage unit; which "may mean" other parts are also absent. The pen drive amplifier and or any preamplifiere/filter aspect is another additional problem that needs a solution with this. The paper selection (heat sensitive and/or even ink paper) is also very difficult to obtain for the width it "should" use. Drum recorders have a fascinating visual appeal to the general public.......but......it would likely be alot cheaper, and with ALOT less hassle overall to go with a computer and A/D card approach. Take care, Meredith BOB BARNS wrote: > Hi, gang, > Ebay.com has an item which may be of interest. > Item # 3106334236 Ends Jan-15-03 15:51:29 PST > "This auction is for a United Electro Dynamics Type DR 273 > seismograph/drum recorder. The unit has three servo motor driver pens > which write on a rotating lead screw driven drum in a continuous chart > from the top of the chart to the bottom." > This is three large drums on the same shaft. > Beware of the $95 crating charge. > Bob Barns > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fwd: USGS Press Release -- Scientists Update New Madrid Earthquake Forecasts From: RLLaney@....... Date: Mon, 13 Jan 2003 18:21:38 EST Hi all: Thought the group might be interested in this. Bob Laney Salem, Oregon Hi all:

Thought the group might be interested in this.

Bob Laney
Salem, Oregon News Release U.S. Department of the Interior U.S. Geological Survey Release: Contact: January 13, 2003 Eugene Schweig Joan Gomberg Address: Email: 3876 Central Ave . schweig@........ Suite 2 jgomberg@........ Memphis, TN 38152 Phone: 901-678-4974 901-678-4858 Scientists Update New Madrid Earthquake Forecasts Scientists from the U.S. Geological Survey (USGS) and the Center for Earthquake Research and Information at the University of Memphis have updated their expectations for earthquakes in the New Madrid Seismic Zone. The new forecasts estimate a 7 to 10 percent chance, in the next 50 years, of a repeat of a major earthquake like those that occurred in 1811-1812, which likely had magnitudes of between 7.5 and 8.0. There is a 25 to 40 percent chance, in a 50-year time span, of a magnitude 6.0 or greater earthquake. The earthquake probabilities in this region have changed considerably since the most commonly cited forecast published in 1985. The new probabilities show an increased chance of larger (7.5-8.0 magnitude) earthquakes and a lesser chance of magnitude 6.0 and greater earthquakes. Meanwhile, estimates of the hazard, or potential for damage caused by shaking, have changed much less. A fact sheet with the new information is available on the web at: http://pubs.usgs.gov/fs/fs-131-02/. "More than fifteen years of research has given us the information to allow us to update our forecasts. But even though the chances of a mid-sized earthquake are reduced, the chances of a devastating earthquake in the region have risen," said USGS scientist Eugene Schweig. "Given this new information, people should absolutely not drop their guard. The threat of an earthquake to Mid-America is still very real." The New Madrid seismic zone is an area of frequent small earthquakes that stretches along the lower Mississippi Valley from just west of Memphis, Tennessee into southern Illinois. It also was the location of a sequence of three or four major earthquakes in 1811 and 1812. Major earthquakes in the range of magnitude 7.5 to 8.0 are capable of causing widespread damage over a large region. Magnitude 6.0 earthquakes can cause serious damage in areas close to the earthquake's epicenter because the hazard (chance of damage in a given area) depends not only on earthquake size, but also on where the earthquakes occur and local soil conditions. In Memphis and throughout the Mid-America region, the USGS is improving its earthquake monitoring and reporting capabilities through the Advanced National Seismic System (ANSS), a nation-wide network of modern strong motion seismometers that can provide emergency-response personnel with real-time "shaking" information within minutes of an earthquake. ANSS stations assist emergency responders within minutes of an event showing not only the magnitude and epicenter, but where damage is most likely to have occurred. Ten new ANSS instruments were recently installed in the Memphis area, 20 have been installed across the mid-America region, and more than 175 have been installed in other vulnerable urban areas outside the central U.S. to provide real-time information on how the ground responds when a strong earthquake happens. "The ultimate goal of ANSS is to save lives and ensure public safety," said Dr. John Filson, U. S. Geological Survey (USGS) Earthquake Program Coordinator. "This information, already available in Southern California, is generated by data from seismic instruments installed in urban areas and has revolutionized the response time of emergency managers to an earthquake, but its success depends on further deployment of instruments in other vulnerable cities." In 1997, during the reauthorization of the National Earthquake Hazards Reduction Program, Congress asked for an assessment of the status and needs of earthquake monitoring. The result was the authorization of ANSS to be implemented by the USGS. The system, when fully implemented, would integrate all regional and national networks with 7,000 new seismic instruments, including 6,000 new strong-motion sensors in 26 at-risk urban areas. To date, approximately 350 instruments have been installed nationwide. New USGS National Seismic Hazard Maps depict these hazard or likelihood of ground shaking. The USGS and its partners in universities and state geological surveys are preparing more detailed hazard maps for Memphis and other areas that include the effects of local soil conditions. For more information see http://geohazards.cr.usgs.gov/eq/. The goal of USGS earthquake monitoring is to mitigate risk - using better instruments to understand the damage shaking causes and to provide information to help engineers create stronger and sounder structures that ensure vital infrastructures, utility, water, and communication networks keep operating safely and efficiently. As the Nation's science agency for natural resources, hazards and the environment, the USGS is committed to meeting the health, safety and knowledge needs of the changing world around us. ***www.usgs.gov*** Butch Kinerney Public Affairs Specialist USGS Office of Communications 703-648-4732 bkinerney@........ Subject: Something Happening?? From: "Jan D. Marshall" jandmarshall@............ Date: Wed, 15 Jan 2003 18:05:02 -0700 I am getting a lot of activity right now on my unit -- whats up?? 1/15/03 23:57UTC Jan Marshall jandmarshall@............ http://myweb.cableone.net/jandmarshall/ Nampa, ID
I am = getting a lot=20 of activity right now on my unit -- whats up??
 
1/15/03  =20 23:57UTC

Jan Marshall
jandmarshall@............
http://myweb.cableone.net= /jandmarshall/
Nampa, ID

 
Subject: Re: Something Happening?? From: Stephen & Kathy skmort@.......... Date: Wed, 15 Jan 2003 17:13:42 -0800 My alarm started going off at 21:51:37 near Pilot Hill Calif. USA It is going to be a good sized one at a distance from me!!! Stephen Mortensen PSN Station #55 38.828N 120.979W > "Jan D. Marshall" wrote: > > I am getting a lot of activity right now on my unit -- whats up?? > > 1/15/03 23:57UTC > > Jan Marshall > jandmarshall@............ > http://myweb.cableone.net/jandmarshall/ > Nampa, ID > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Something Happening?? From: "Jan D. Marshall" jandmarshall@............ Date: Wed, 15 Jan 2003 18:28:12 -0700 well its time here was actually 00:57:30 UTC Lat 43.5462459 Long -116.5470666 Jan Marshall jandmarshall@............ http://myweb.cableone.net/jandmarshall/ Nampa, ID -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@................. Behalf Of Stephen & Kathy Sent: Wednesday, January 15, 2003 6:14 PM To: psn-l@.............. Subject: Re: Something Happening?? My alarm started going off at 21:51:37 near Pilot Hill Calif. USA It is going to be a good sized one at a distance from me!!! Stephen Mortensen PSN Station #55 38.828N 120.979W > "Jan D. Marshall" wrote: > > I am getting a lot of activity right now on my unit -- whats up?? > > 1/15/03 23:57UTC > > Jan Marshall > jandmarshall@............ > http://myweb.cableone.net/jandmarshall/ > Nampa, ID > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: OOPS Something Happening?? From: Stephen & Kathy skmort@.......... Date: Wed, 15 Jan 2003 17:31:20 -0800 OOPs,,, for some unknown reason my recording time is about 4 hours off???? Sooooo,, ignore the posted time on my last email,, I had a blue screen when I checked, after the alarm, but didn't realize it had affected my recording as it was still going when I cleared the screen!!! Sorry, Stephen > "Jan D. Marshall" wrote: > > I am getting a lot of activity right now on my unit -- whats up?? > > 1/15/03 23:57UTC > > Jan Marshall > jandmarshall@............ > http://myweb.cableone.net/jandmarshall/ > Nampa, ID > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Something Happening?? From: Seisguy@....... Date: Wed, 15 Jan 2003 20:41:30 EST well, there is an event on the anza network that occured at 00:56 UTC. M3.1 near Pomona. No other sites have it posted. http://eqinfo.ucsd.edu/current_earthquakes/anza/regional.html Mike O'Bleness Palm Springs, CA well, there is an event on the anza network that occured at 00:56 UTC.

M3.1 near Pomona.  No other sites have it posted.

http://eqinfo.ucsd.edu/current_earthquakes/anza/regional.html

Mike O'Bleness
Palm Springs, CA Subject: Re: Something Happening?? From: Stephen & Kathy skmort@.......... Date: Wed, 15 Jan 2003 18:06:32 -0800 FYI,, looking at the world webicorders, Alaska and New Mexico have about the same starting time with Texas and Hawaii a little behind that,, based on that, my first guess would put it in lower Alaska, south western Canada, area???? If so, it could be in the 6 to 7 range. Stephen 38.828N 120.979W Seisguy@....... wrote: > > well, there is an event on the anza network that occured at 00:56 UTC. > > M3.1 near Pomona. No other sites have it posted. > > http://eqinfo.ucsd.edu/current_earthquakes/anza/regional.html > > Mike O'Bleness > Palm Springs, CA __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Something Happening?? From: meredithlamb meredithlamb@............. Date: Wed, 15 Jan 2003 22:32:51 -0700 Jan, Nice record you have on the Oregon quake at: http://24.116.175.108/live%20data.htm Perhaps (?), their was a after shock ~ 0520 UTC (?), but, it might be much further away. Like the marble base, and pics at: http://24.116.175.108/Over%20all%20pictures.htm Take care, Meredith "Jan D. Marshall" wrote: > well its time here was actually 00:57:30 UTC Lat 43.5462459 > Long -116.5470666 > > Jan Marshall > jandmarshall@............ > http://myweb.cableone.net/jandmarshall/ > Nampa, ID > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fwd: Problems with Earthquake Data From: John & Jan Lahr johnjan@........ Date: Thu, 16 Jan 2003 20:58:57 -0700 Does anyone live close enough to Eldon, Missouri, to give this teacher a hand? Thanks, John Lahr USGS Golden, CO http://jjlahr.com/science/ >------------- Begin Forwarded Message ------------- > >Mailing-List: contact irised-help@.................. run by ezmlm >X-No-Archive: yes >List-Post: >List-Help: >List-Unsubscribe: >List-Subscribe: >Delivered-To: mailing list irised@................. >From: Drmuloc@....... >Date: Thu, 16 Jan 2003 13:12:46 EST >Subject: Problems with Earthquake Data >To: irised@................. > >I'm the science teacher in Eldon Missouri that is having major problems with >her seismograph. Is there anyone out there who is close by that can help me >set up a seismograph that doesn't record the pitter patter of anxious middle >school children as they cross the concrete floor? > >I have had the computer person get us on line. I have my program set up. I >just want someone to come to the school and tutor me for 30 minutes to an >hour. They also need to look at my computer to see if everything is correct. > Is this possible? > >My husband says that everything is correct on the computer (He is a Nuclear >Physicist-Adjunct Proff.) Somehow, I cannot get his interpretations about >how to run this equipment properly into my learning curve. > >My principal says that she will send me to wherever I need to go to learn >everything, but I hate to go to far because I don't like to be out of the >classroom. > >Thanks, > >M. A. Martin > >------------- End Forwarded Message ------------- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Problems with Earthquake Data From: steve hammond shammon1@............. Date: Thu, 16 Jan 2003 21:42:23 -0800 Hi John, I'll be happy to supply ongoing mentoring help via the Internet if you can't find somebody closer. Regards, Steve Hammond -----Original Message----- From: John & Jan Lahr [SMTP:johnjan@......... Sent: Thursday, January 16, 2003 7:59 PM To: psn-l@.............. Subject: Fwd: Problems with Earthquake Data Does anyone live close enough to Eldon, Missouri, to give this teacher a hand? Thanks, John Lahr USGS Golden, CO http://jjlahr.com/science/ >------------- Begin Forwarded Message ------------- > >Mailing-List: contact irised-help@.................. run by ezmlm >X-No-Archive: yes >List-Post: >List-Help: >List-Unsubscribe: >List-Subscribe: >Delivered-To: mailing list irised@................. >From: Drmuloc@....... >Date: Thu, 16 Jan 2003 13:12:46 EST >Subject: Problems with Earthquake Data >To: irised@................. > >I'm the science teacher in Eldon Missouri that is having major problems with >her seismograph. Is there anyone out there who is close by that can help me >set up a seismograph that doesn't record the pitter patter of anxious middle >school children as they cross the concrete floor? > >I have had the computer person get us on line. I have my program set up. I >just want someone to come to the school and tutor me for 30 minutes to an >hour. They also need to look at my computer to see if everything is correct. > Is this possible? > >My husband says that everything is correct on the computer (He is a Nuclear >Physicist-Adjunct Proff.) Somehow, I cannot get his interpretations about >how to run this equipment properly into my learning curve. > >My principal says that she will send me to wherever I need to go to learn >everything, but I hate to go to far because I don't like to be out of the >classroom. > >Thanks, > >M. A. Martin > >------------- End Forwarded Message ------------- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Software for the Earthscope From: el.pillan@........... Date: Fri, 17 Jan 2003 13:50:23 +0100 (CET) Does anyone know any software compatible with the Earthscope (PS2) from Kinemetrics? Many thanks in advance for any suggestions you might have. Kind regards from Germany, Werner Keller / www.povi.org __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Software for the Earthscope From: ChrisAtUpw@....... Date: Fri, 17 Jan 2003 14:44:57 EST In a message dated 17/01/03, el.pillan@........... writes: > Does anyone know any software compatible with the Earthscope (PS2) from > Kinemetrics? > > Hi Werner, Looking at http://www.kinemetrics.com/earthscope.html Kinemetrics are supposed to supply a complete suite of software, 2 MB in all. The sensor is vertical 1 to 30 Hz and seems to have an 18 bit A/D. It does not record precise timing and is provided with 4 m of cable to connect to a com port of the host computer. Regards, Chris Chapman In a message dated 17/01/03, el.pillan@........... writes:

Does anyone know any software compatible with the Earthscope (PS2) from
Kinemetrics?

Werner Keller / www.povi.org


Hi Werner,

      Looking at http://www.kinemetrics.com/earthscope.html Kinemetrics are supposed to supply a complete suite of software, 2 MB in all. The sensor is vertical 1 to 30 Hz and seems to have an 18 bit A/D. It does not record precise timing and is provided with 4 m of cable to connect to a com port of the host computer.

      Regards,

      Chris Chapman Subject: BIG Quake From: David A Nelson davenn@............... Date: Mon, 20 Jan 2003 21:13:32 +1100 hi all A magnitude 7.5 earthquake IN THE SOLOMON ISLANDS has occurred at: 10.42S 160.70E Depth 33km Mon Jan 20 08:43:06 2003 UTC cheers Dave N In God I trust; All others pay cash :) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Colorado School of Mines Seismometer Competition From: John & Jan Lahr johnjan@........ Date: Mon, 20 Jan 2003 08:39:28 -0700 During the Fall of 2002 the freshmen at the Colorado School of Mines worked on designing of an inexpensive seismic system. The details are given here: http://www.jjlahr.com/science/psn/epics/ In December the best designs were selected and some of the students' reports are posted here: http://www.jjlahr.com/science/psn/epics/reports/ I will continue to add reports as I receive them. Although none of the designs are ready to go as it, some of the teams are continuing to make refinements this semester. Over all this was a great educational exercise, as the students have a gained a greater appreciation of the difficulty of designing and then building a sensitive instrument. Also as they continue at CSM, they will learn how useful their math, physics, and engineering courses would have been had they taken them prior to trying to build a seismometer! In their senior year, all of the CMS students select an engineering project to work on. I'm hoping that for some the challenge of designing an inexpensive seismic sensor will remain, and that they will apply their newly acquired skills to this topic once again. Cheers, John Lahr __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Acouple neodymium magnets sellers noted From: meredithlamb meredithlamb@............. Date: Mon, 20 Jan 2003 15:38:16 -0700 Hi all, One might note that a canadian seller has a fair variety of magnets at what appears to be at quite reasonably priced items....and they appear to be quite below U.S. prices. Most magnets seem to be gauss rated at MGOe of 38 which is alittle above the (gauss) ratings of alot of normally available magnets. I would guess the shipping costs will kick up the overall price somewhat higher for country to country deliveries, obviously. The E-Bay store name is: Hamilton Core Drill Bits http://www.stores.ebay.com/id=14430047 His E-Bay feedback looks to be exceptionally good; with 647 positives, 10 neutrals, and zero negative. We've no idea if he may offer other magnets in the future or this is a one time deal. I've no prior personal experience with this seller. Most items are only offered within the next two days or so. Theres quite a variety of sizes. So, if you've been waiting for a certain size to fit that certain sized seismo coil, or project .....this "might" be the ticket for you. ************* There is also another new neo mag seller that has a variety of magnets within the U.S. His web site is at: http://www.engconcepts.net/Magnets/Magnets.htm The gauss ratings of the magnets vary, as does the sizes and shapes he has; but I would say the prices are also fairly reasonable. I've no prior personal experience with this seller. *********** Perhaps now the increased ratings and sizes of the available neo magnets are becoming less expensive than in the past... which is very good. Take care, Meredith __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Ref: More Diamagnetism From: "Connie and Jim Lehman" lehmancj@........... Date: Mon, 20 Jan 2003 22:28:26 -0500 PSN people---those interested in diamagnetism and possible seismic = sensor applications may find the recent article in Feb. '03, "The = Physics Teacher" helpful----a horizontal version of the previous = vertical design--- Jim Lehman=20
PSN people---those = interested=20 in diamagnetism and possible seismic sensor applications may find = the=20 recent article in Feb. '03, "The Physics Teacher" helpful----a = horizontal=20 version of the previous vertical design---
          &nbs= p;            = ;            =   =20 Jim Lehman 
Subject: Re: Ref: More Diamagnetism From: John & Jan Lahr johnjan@........ Date: Mon, 20 Jan 2003 21:53:24 -0700 Another aspect of the Physics Teacher article was demonstrating that water was
diamagnetic (repelled by a magnet).  I've posted a page in which I've managed to
recreate the demonstration:
http://jjlahr.com/science/physics/diamag/water/
Cheers,
John

At 08:28 PM 1/20/2003, you wrote:
PSN people---those interested in diamagnetism and possible seismic sensor applications may find the recent article in Feb. '03, "The Physics Teacher" helpful----a horizontal version of the previous vertical design---
                                      Jim Lehman
Subject: Re: Ref: More Diamagnetism From: meredithlamb meredithlamb@............. Date: Mon, 20 Jan 2003 22:26:12 -0700 Hi Jim, Thanks (!) for the reference too: http://ojps.aip.org/tpt/ For those curious, click on February 2003, and go to "More Diamagnetism Demonstrations" written by Chris Conery. It has either standard HTML or Adobe PDF versions available. I note they use some of the best diamagnetic pyrolytic graphite known and likely their levitated magnet is also highly rated at a MGOe of very likely 45. It "used to be" that this pyrolytic graphite could only be obtained at a very high cost (~$400, for a 6" x 6" x ~ .1" thick piece!). They DO take a unusual step with using the ceramic magnets, to the sides of the levitated magnet.....one could use a single magnet that is height adjustable (although this might be somewhat in the way of the view of the surface). The fluid actually helps the magnet levitate higher than normal. Their approach actually seems to entail a number of additional items to produce the same effect that John Lahr's considerably more simplified version demonstrates. See: http://jjlahr.com/science/physics/diamag/water/ Actually, this water diamagnetism hasn't heretofore been as well demonstrated as via these 2 web sites that I'am aware of. The newer and better material available has made some of these demonstration units much more feasible to do, or try. Congratulations to the innovative builders! Take care, Meredith Lamb Connie and Jim Lehman wrote: > PSN people---those interested in diamagnetism and possible seismic > sensor applications may find the recent article in Feb. '03, "The > Physics Teacher" helpful----a horizontal version of the previous > vertical design--- Jim Lehman Hi Jim,

Thanks (!) for the reference too:

http://ojps.aip.org/tpt/

For those curious, click on February 2003, and go to "More
Diamagnetism Demonstrations" written by Chris Conery.  It has
either standard HTML or Adobe PDF versions available.

I note they use some of the best diamagnetic pyrolytic graphite
known and likely their levitated magnet is also highly rated at
a MGOe of very likely 45.  It "used to be" that this pyrolytic
graphite could only be obtained at a very high cost (~$400, for a
6" x 6" x ~ .1" thick piece!).  They DO take a unusual
step with using the ceramic magnets, to the sides of the levitated
magnet.....one could use a single magnet that is height adjustable
(although this might be somewhat in the way of the view of the
surface).  The fluid actually helps the magnet levitate higher than
normal.

Their approach actually seems to entail a number of additional
items to produce the same effect that John Lahr's considerably
more simplified version demonstrates.  See:

http://jjlahr.com/science/physics/diamag/water/

Actually, this water diamagnetism hasn't heretofore been as
well demonstrated as via these 2 web sites that I'am aware
of.  The newer and better material available has made some
of these demonstration units much more feasible to do, or try.
Congratulations to the innovative builders!

Take care, Meredith Lamb

Connie and Jim Lehman wrote:

PSN people---those interested in diamagnetism and possible seismic sensor applications may find the recent article in Feb. '03, "The Physics Teacher" helpful----a horizontal version of the previous vertical design---                                      Jim Lehman
Subject: Re: Ref: More Diamagnetism From: ChrisAtUpw@....... Date: Tue, 21 Jan 2003 08:40:55 EST In a message dated 21/01/03, meredithlamb@............. writes: > Hi Jim, Thanks (!) for the reference too: http://ojps.aip.org/tpt/ For those > curious, click on February 2003, and go to "More Diamagnetism > Demonstrations" written by Chris Conery. It has either standard HTML or > Adobe PDF versions available. I note they use some of the best diamagnetic > pyrolytic graphite known and likely their levitated magnet is also highly > rated at a MGOe of very likely 45. It "used to be" that this pyrolytic > graphite could only be obtained at a very high cost (~$400, for a 6" x 6" x > ~ .1" thick piece!). They DO take a unusual step with using the ceramic > magnets, to the sides of the levitated magnet.....one could use a single > magnet that is height adjustable (although this might be somewhat in the > way of the view of the surface). The fluid actually helps the magnet > levitate higher than > Hi Meredith, I get an 'We can not find the file....' when I click on the above. If you copy the text to Web Address it works, but you then need to click on 'Papers'. Ceramic magnets have relatively low fields and are quite temperature sensitive. They are often fitted with soft iron cap plates to enable the field to be concentrated, such as in loudspeaker applications. Regards, Chris Chapman In a message dated 21/01/03, meredithlamb@............. writes:

Hi Jim, Thanks (!) for the reference too: http://ojps.aip.org/tpt/ For those curious, click on February 2003, and go to "More Diamagnetism Demonstrations" written by Chris Conery.  It has either standard HTML or Adobe PDF versions available. I note they use some of the best diamagnetic pyrolytic graphite known and likely their levitated magnet is also highly rated at a MGOe of very likely 45.  It "used to be" that this pyrolytic graphite could only be obtained at a very high cost (~$400, for a 6" x 6" x ~ .1" thick piece!).  They DO take a unusual step with using the ceramic magnets, to the sides of the levitated magnet.....one could use a single magnet that is height adjustable (although this might be somewhat in the way of the view of the surface).  The fluid actually helps the magnet levitate higher than
normal.


Hi Meredith,

      I get an 'We can not find the file....' when I click on the above. If you copy the text to Web Address it works, but you then need to click on 'Papers'.
      Ceramic magnets have relatively low fields and are quite temperature sensitive. They are often fitted with soft iron cap plates to enable the field to be concentrated, such as in loudspeaker applications.

      Regards,

      Chris Chapman Subject: Re: Ref: More Diamagnetism From: meredithlamb meredithlamb@............. Date: Tue, 21 Jan 2003 11:05:40 -0700 Hi Chris, John Lahr noted this web address correction: http://ojps.aip.org/journals/doc/PHTEAH-ft/vol_41/iss_2/74_1-div0.html He also noted that links for other versions are on this page: http://ojps.aip.org/dbt/dbt.jsp?KEY=PHTEAH&Volume=CURVOL&Issue=CURISS The "Physics Teacher" server seems to be quite slow to respond. I agree on your magnets statement; and....yes, they may need a added mechanical arrangement for the temperature ranges changes that can occur. For that "general" arrangement, only a temperature change of only afew degrees can have a big levitation height change in position. Your iron sheet add-on idea with other diamagnetic setups involving seismic designs is quite a excellent and dramatic improvement, where its possible to do so. Take care, Meredith ChrisAtUpw@....... wrote: > > Hi Meredith, > > I get an 'We can not find the file....' when I click on the > above. If you copy the text to Web Address it works, but you then need > to click on 'Papers'. > Ceramic magnets have relatively low fields and are quite > temperature sensitive. They are often fitted with soft iron cap plates > to enable the field to be concentrated, such as in loudspeaker > applications. > > Regards, > > Chris Chapman Hi Chris,

John Lahr noted this web address correction:
 http://ojps.aip.org/journals/doc/PHTEAH-ft/vol_41/iss_2/74_1-div0.html

He also noted that links for other versions are on this page:
 http://ojps.aip.org/dbt/dbt.jsp?KEY=PHTEAH&Volume=CURVOL&Issue=CURISS

The "Physics Teacher" server seems to be quite slow to respond.

I agree on your magnets statement; and....yes, they may need a
added mechanical arrangement for the temperature ranges
changes that can occur.  For that "general" arrangement, only
a temperature change of only afew degrees can have a big
levitation height change in position.

Your iron sheet add-on idea with other diamagnetic setups
involving seismic designs is quite a excellent and dramatic
improvement, where its possible to do so.

Take care, Meredith

ChrisAtUpw@....... wrote:

 
Hi Meredith,

      I get an 'We can not find the file....' when I click on the above. If you copy the text to Web Address it works, but you then need to click on 'Papers'.
      Ceramic magnets have relatively low fields and are quite temperature sensitive. They are often fitted with soft iron cap plates to enable the field to be concentrated, such as in loudspeaker applications.

      Regards,

      Chris Chapman

Subject: SPAM from my E-mail address From: Bob Fryer bfryer@............ Date: Tue, 21 Jan 2003 13:53:19 -0800 Hello friends, I am getting "rejected E-mails" from Mail Delivery System and others. The items from Mail Delivery System are 105 k in length, suggesting that the original is about 100 k. The addressees are often unknown to me, and are about subjects that I have never hear of. If you have any doubts about the subject... do not open the E-mail. The good news is that, since I work on a Mac, it does not seem that a virus is involved. I suspect that they picked picked up my address from my websites. Until this ceases, my E-mail Subject: lines will contain my initials, BF. I apologize for any difficulty you may experience because of these mental cretins. Take care, Bob Fryer -- earthquake WARNING research Animals, People, Scientific Evidence www.earthquakewarning.org __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Large Quake rolling in now From: Jeff Batten jeff.batten@........ Date: Tue, 21 Jan 2003 18:22:10 -0800 Picking up a large event. Looks very large. No one felt it in S cal. Jeff Jeff Batten Electronics Technician III CSUN Physics and Astronomy San Fernando Observatory 818-677-2768 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Quake rolling in now From: DGentry509@....... Date: Tue, 21 Jan 2003 21:33:05 EST Mexico City 7.6 as reported by FCN at 1830 PST. D Gentry Mexico City 7.6 as reported by FCN at 1830 PST.

D Gentry Subject: hi 3.2 From: allan egleston allane@......... Date: Tue, 21 Jan 2003 18:34:09 -0800 A 3.2 event just occured 6 miles of Cabazon Ca __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Quake rolling in now From: "Larry Cochrane" cochrane@.............. Date: Tue, 21 Jan 2003 18:35:13 -0800 Looks like a magnitude of ~ Ms7.4 off of the coast of Mexico. This is based on information from my sensors and a few of the broadband sensors I am monitoring. -Larry Cochrane Redwood City, PSN ----- Original Message ----- From: "Jeff Batten" To: Sent: Tuesday, January 21, 2003 6:22 PM Subject: Large Quake rolling in now > > > > Picking up a large event. Looks very large. No one felt it in S cal. > > Jeff > Jeff Batten > Electronics Technician III > CSUN Physics and Astronomy > San Fernando Observatory > 818-677-2768 > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Quake rolling in now From: Dgw5319@....... Date: Tue, 21 Jan 2003 21:36:02 EST Looks like maybe off the coast of Mexico? M 6.4+ EMSC Real Time Seismicity RedPuma Global List and Waveforms Dave Looks like maybe off the coast of Mexico?  M 6.4+

EMSC Real Time Seismicity

RedPuma Global List and Waveforms

Dave Subject: hi update From: allan egleston allane@......... Date: Tue, 21 Jan 2003 18:39:11 -0800 mag 7 in mexico __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Large Quake rolling in now From: meredithlamb meredithlamb@............. Date: Tue, 21 Jan 2003 19:40:52 -0700 Hi Jeff and all, Yes indeed! Monitor here in Denver, totally "smeared" with signal for ~ 10 minutes. Dangerious quake. Just for interest, I had a undampened diamagnetic seismo setup on the kitchen table (very solid, very little deflection upon approach), and its pendulum was oscillating with about 1" of lateral horizontal travel. Kind of rare to visually observe such. Take care, Meredith Jeff Batten wrote: > Picking up a large event. Looks very large. No one felt it in S cal. > > Jeff > Jeff Batten > Electronics Technician III > CSUN Physics and Astronomy > San Fernando Observatory > 818-677-2768 > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: mexico quake From: TESMECO@....... Date: Tue, 21 Jan 2003 21:57:45 EST looks like a 7.6 no damage reports yet not felt in riverside ca looks like a 7.6 no damage reports yet
not felt in riverside ca Subject: Mexico quake From: meredithlamb meredithlamb@............. Date: Tue, 21 Jan 2003 20:06:35 -0700 Hi all, Reuters has some ~ priminary news. See: http://asia.reuters.com/newsArticle.jhtml?type=topNews&storyID=2084917 Meredith __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Colorado School of Mines Seismometer Competition From: meredithlamb meredithlamb@............. Date: Thu, 23 Jan 2003 21:52:32 -0700 Hi John and all, Thanks John for doing ALOT of work with posting the entrys on your web site! I find them very interesting to explore, and I'am looking forward to seeing any remaining papers eventually. The diamagnetic one was of particular interest too me of course. They used "end magnets" which seems to double the period of the levitated spectrographic rod of a similar arrangement here I copyed (but without end magnets and using curved filed iron spacers). Chris Chapman has made earlier similar comments on this in the past also. I've tried using other size magnets where I put the "end magnets" across the row/s tops ends, and it also has a similar effect. Most interesting; as it eliminates having to hand file the iron spacers center region with a man made curvature; which makes it alot easier to setup and seems to present a consistent seismo period, for ~ possible easy replication by others. Take care, Meredith John & Jan Lahr wrote: > During the Fall of 2002 the freshmen at the Colorado School of Mines worked on > designing of an inexpensive seismic system. The details are given here: > > http://www.jjlahr.com/science/psn/epics/ > > In December the best designs were selected and some of the students' > reports are > posted here: > http://www.jjlahr.com/science/psn/epics/reports/ > > I will continue to add reports as I receive them. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: EMON PROBLEM From: RADIOTEL@....... Date: Sat, 25 Jan 2003 21:36:21 EST NEED HELP WITH EMON. I am using Emon with w CIO Das-8 A/D card. It works great until I press the F8 key on the computer to view the file. The the screen reflects : Loading QUAKEVU.INI file... Error 7 at line 0 , press any key Can anyone tell me how to fix this problem. Sure would appreciate the assistance. NEED HELP WITH EMON.  I am using Emon with w CIO Das-8 A/D card.  It works great until I press the F8 key on the computer to view the file.  The the screen reflects :
Loading QUAKEVU.INI file...

Error 7 at line 0 , press any key
Can anyone tell me how to fix this problem.  Sure would appreciate the assistance.
 Subject: New WinQuake Beta Release From: "Larry Cochrane" cochrane@.............. Date: Sun, 26 Jan 2003 03:19:51 -0800 Hi Everyone, I've released a new beta version of WinQuake, see this page for a download link and release notes: http://www.seismicnet.com/wqdocs/wqbeta.html Here's what's new in this release. For a complete list of new features and how to use them please see the release notes. Both WinQuake and WinSDR (the current beta version just released) now support a new data structure in the PSN Type 4 event file record. The new structure contains additional information about the sensor channel. The new data fields are: Sensor output voltage in volts per cm of movement, amplifier gain between the sensor and the A/D converter and the peak A/D input volts. This information and the number of A/D bits make up the Sensor Sensitivity field in the main fix header section. See this page for more information on the PSN Type 4 event file format: http://www.seismicnet.com/psnformat4.html WinQuake now calculates Mb or Body Wave magnitude. The program uses this formulate to calculate Mb: mb = log10(A/T) + 0.01*D + 5.9 A = Peak P wave displacement amplitude in micrometers, T = Period of the displacement amplitude and D = Distance in degrees. The program can also calculate the Ms or Mb peak wave period used by the Ms and Mb formulas. In the Time Domain Filter dialog box the user can now enter the period in seconds rather then the frequency. To do this add an 's' after the number. Example: Entering "20s" will produce a frequency of 0.05 Hz. The user can now crop an event file. To do this zoom into the area of interest and then use the View / Crop menu items. The user can now search for event files on their system. The search includes filters like min/max magnitude, event to station distance, start and end times, as well as other filters. To make the search faster, the program can create a database file. This file contains information about each event file in a directory and any subdirectories. The database file can be used for the search rather then opening each file on your system. This drastically improves the search time if you have a lot of event files. WinQuake now as a Magnitude Calculator dialog box. See the release notes for all of the info on this new dialog box. The Y-Scaling has been changed. The Y-Scale number now represents the peak data to display. Example: If WinQuake is displaying A/D counts and the Y-Scale number is set to 1000, WinQuake will display 0 to +-1000 counts. The program can display the following Y-Scale units: A/D Counts, this is the default if the Sensor Sensitivity number and A/D Input Volts fields of the header are 0, Sensor Units (cm, mm etc) if the Sensor Sensitivity is known, amplifier input voltage, this is the voltage from the sensor element, if the amp gain and A/D input voltage is known, and A/D volts if this information is available in the header. The map window's title now displays the Y-Scale in the title bar of the map window. This is the distance in km displayed between the top and bottom of the window. That's it for the new features. I'm currently working on a major rewrite of the program so that more then one event file can be displayed in the same event window. The ability to add new event files to the same window will be limited to Z, N-S and E-W channels with the same start / end times and sample rate. This way the data from a two or three component sensor can be displayed and analyzed in one window. I also will be adding the ability to read and write a PSN volume set that can contain two or three event files. Once I have this working and released, I will modify WinSDR so it can support a two or three channel volume set file that can be read in with WinQuake. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New WinQuake Beta Release From: John & Jan Lahr johnjan@........ Date: Sun, 26 Jan 2003 08:44:31 -0700 Hi Larry, Sounds like a lot of helpful new features for WinQuake. In your magnitude calculations, do you account for the variation in overall gain between ~1s P waves for mb and ~ 20 s surface waves for MS? To a first approximation if the gain of the system were know at these two frequencies, that would be enough for rough magnitude determinations. AmaSeis does not write the new PSN Type 4 format now. What would be the advantages of making this change? Can the old format be converted to Type 4 and then the file augmented with additional data, or does the change need to be made in AmaSeis? Cheers, John Lahr At 04:19 AM 1/26/2003, you wrote: >I've released a new beta version of WinQuake, see this page for a download >link and release notes: __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: EMON PROBLEM From: steve hammond shammon1@............. Date: Sun, 26 Jan 2003 10:07:22 -0800 Quakevu is the display program that Ted Black created. It is a stand alone dos program QUAKEVU.EXE. I'll send you a copy of it if you don't have it. I use EMON for data capture and Larry's Winquake for viewing the data. Regards, Steve Hammond PSN San Jose, Aptos CA -----Original Message----- From: RADIOTEL@....... [SMTP:RADIOTEL@........ Sent: Saturday, January 25, 2003 6:36 PM To: psn-l@.............. Subject: Re: EMON PROBLEM NEED HELP WITH EMON. I am using Emon with w CIO Das-8 A/D card. It works great until I press the F8 key on the computer to view the file. The the screen reflects : Loading QUAKEVU.INI file... Error 7 at line 0 , press any key Can anyone tell me how to fix this problem. Sure would appreciate the assistance. << File: ATT00004.html >> __________________________________________________________ Public Seismic Network Mailing List