Subject: Re: Digest from 09/30/2004 00:00:17 From: Roger Sparks rsparks@.......... Date: Fri, 01 Oct 2004 09:53:17 -0700 Good morning all, I am viewing the multiple quakes from Mt. St. Helens on Amaseis which can present the data from 24 hours on one screen. The larger quakes are coming with surprising regularity. One particularly noticeable grouping forms a slanted line on the screen and has an average interval of about 58.4 minutes between events. The larger events which can be detected here (about 148 km or 91 miles away in Ellensburg, Washington) occur about every 5 to 6 minutes. I can send a bmp file which is a screen shot of Amaseis to anyone who is interested. Best, Roger __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Excel prog. to anal. the STS1 seismometer From: BOB BARNS royb1@........... Date: Wed, 06 Oct 2004 11:43:12 -0400 Hi gang, My friend Brett has constructed a elaborate spreadsheet which allows exploration of the design parameters of the STS1 seismometer. The package (with a .rtf file of explanation) is at: http://bnordgren.org/seismo/ I was able to open it but could not run it because I don't have an aux. program for my version of Excel. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Excel prog. to anal. the STS1 seismometer From: ChrisAtUpw@....... Date: Wed, 6 Oct 2004 15:32:43 EDT In a message dated 06/10/04, royb1@........... writes: > The package (with a .rtf file of explanation) is at: > http://bnordgren.org/seismo/ > I was able to open it but could not run it because I don't have an > aux. program for my version of Excel Hi Bob, Can you advise me please? When I try to download the programme called http://bnordgren.org/seismo/vertgeom.dxf my Microsoft browser insists on treating it as html and renames it vertgeom_dxf.htm or as vertgeom_dfx.txt Can you tell me how I get the .dfx file that I need please? Regards, Chris Chapman In a message=20= dated 06/10/04, royb1@........... writes:

The package (with a .rtf fi= le of explanation) is at:
    http://bnordgren.org/seismo/
  I was able to open it but could not run it because I don't=20= have an=20
aux. program for my version of Excel


Hi Bob,

      Can you advise me please?=20
      When I try to download the programm= e called=20
http://bnordgren.org/seismo/vertgeom.dxf my Microsoft browser insists on= treating it as html and renames it vertgeom_dxf.htm or as vertgeom_dfx.txt
      Can you tell me how I get the .dfx=20= file that I need please?=20

      Regards,

      Chris Chapman
Subject: Re: Excel prog. to anal. the STS1 seismometer From: BOB BARNS royb1@........... Date: Wed, 06 Oct 2004 20:07:26 -0400 Chris, I goofed--the file you want for the STS1 is sts1solve.zip Brett says that vertgeom.dfx is a generic CAD file and can be gotten by a right click and choosing "save target as" or just rename what you got as .dfx Bob ChrisAtUpw@....... wrote: > In a message dated 06/10/04, royb1@........... writes: > >> The package (with a .rtf file of explanation) is at: >> http://bnordgren.org/seismo/ >> I was able to open it but could not run it because I don't have an >> aux. program for my version of Excel > > > > Hi Bob, > > Can you advise me please? > When I try to download the programme called > http://bnordgren.org/seismo/vertgeom.dxf my Microsoft browser insists on > treating it as html and renames it vertgeom_dxf.htm or as vertgeom_dfx.txt > Can you tell me how I get the .dfx file that I need please? > > Regards, > > Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: file for STS1 From: BOB BARNS royb1@........... Date: Wed, 06 Oct 2004 20:10:32 -0400 Hi gang, I failed to say in my previous (about the analysis of the STS1) that the file is sts1solve.zip. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ebay auctions From: BOB BARNS royb1@........... Date: Wed, 20 Oct 2004 09:38:56 -0400 Hi gang, Elementary Seismology Richter 1958 Item number: 2495719500 ends Oct. 25 ----- Triaxial indicating Seismometer Earthquake Volcano HOT! Item number: 6125669899 ends Oct. 24. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Seis Info From: "Edward Ianni" edwianni1@........... Date: Thu, 21 Oct 2004 10:48:38 -0400 Hi All; I recently picked up an old sprengnether seis on ebay. ID = number is 3844382780 I was wondering if any of our members can give me = some additional information on it . Pictures of it and a brief = description are at the above ebay site also. Thanks, Ed.
 
 
Hi All;
 
I recently picked up an old = sprengnether=20 seis on ebay. ID number is 3844382780   I was = wondering if=20 any of our members can give me some additional information on=20 it . Pictures of it and a brief description are at the = above ebay=20 site also. Thanks,=20 = Ed.
Subject: Something BIG coming in now From: JD Cooley jdcooley@....... Date: Sat, 23 Oct 2004 02:38:44 -0700 Looks like it is close to Korea just before 0900Z.
"JD"
Subject: Earth Hum!!!! From: "Connie and Jim Lehman" lehmancj@........... Date: Sun, 24 Oct 2004 17:47:48 -0400 Recently I saw reference to an article on the parameters of "Earth = Hum"---Real long period waves of 4 to 5 minutes. This translated to a = frequency 16 octives below (256 Hz) middle C. These waveforms are = detectable seemingly anywhere on the Earth's surface. The article can be found in the Sept. 30th '04 issue of Nature = magazine, but didn't give much help in the recording mechanics of such = long waveforms. Can anyone simplify an explanation of how these waves = are detected???? These low frequency oscillations seem to be caused by = winter storms over oceans, and are quite detached from common = microseisms we are familiar with. Jim Lehman
Recently I saw reference to an = article on=20 the parameters of "Earth Hum"---Real long period waves of 4 to 5 = minutes. =20 This translated to a frequency 16 octives below (256 Hz) middle C.  = These=20 waveforms are detectable seemingly anywhere on the Earth's=20 surface.
   The = article can be found=20 in the Sept. 30th '04 issue of Nature magazine, but = didn't give=20 much help in the recording mechanics of such long waveforms. Can = anyone=20 simplify an explanation of how these waves are detected????  These = low=20 frequency oscillations seem to be caused by winter storms over oceans, = and are=20 quite detached from common microseisms we are familiar=20 with.
          &nbs= p;            = ;    =20 Jim Lehman
Subject: willmore MKIIIC/V From: "Steve Shuff" cellectronic@......... Date: Mon, 25 Oct 2004 11:18:27 +0100 Hi all, is any one in possession of technical literature regarding the = Willmore MKIIIC/V seismometer ? I have one which needs repairing and setting up. Regards, Steve
Hi all, is any one in possession of = technical=20 literature regarding the Willmore MKIIIC/V seismometer ?
 
I have one which needs repairing and = setting=20 up.
Regards,=20 Steve
Subject: test From: "Steve Shuff" cellectronic@......... Date: Mon, 25 Oct 2004 11:52:19 +0100 test
test
Subject: Re: Earth Hum! From: ChrisAtUpw@....... Date: Mon, 25 Oct 2004 22:23:36 EDT In a message dated 24/10/04, lehmancj@........... writes: > Recently I saw reference to an article on the parameters of "Earth > Hum"---Real long period waves of 4 to 5 minutes. This translated to a frequency 16 > octives below (256 Hz) middle C. These waveforms are detectable seemingly > anywhere on the Earth's surface. > The article can be found in the Sept. 30th '04 issue of Nature magazine, > but didn't give much help in the recording mechanics of such long waveforms. > Hi Jim, The original Streckeisen STS-1 seismometer had a period of ~850 sec and used a LVDT feedback detector. The Kinemetrics FBA-23 accelerometer works from DC up. The Guralp CMG-3 can work at 360 sec and uses a capacitative detector. It is also possible to use a seismometer with a shorter period and extend the period using digital signal processing, by a factor of up to about 10. Other methods which may be used for sensing very long period signals include extensometers and tiltmeters, often placed deep underground in mine shafts to avoid surface noise. For more information, I suggest you read 'The leaf spring seismometer: design and performance' by E Wielandt and G Streckeisen, Bull Seis Soc America, Vol 72, No. 6, pp2349-2367, 1982. LaCoste came up with an infinite period spring design back in 1934. Basically, you start with a longish period and then apply a feedback loop which defines the response - the S&G seismometers also did that with a 1 sec pendulum - see psn account. There was an Iris conference at Granlibakken last March discussing long period instrument development. See http://www.iris.edu/stations/seisWorkshop04/ The papers are mostly available on line. I hope that this is of some help. Regards, Chris Chapman In a message=20= dated 24/10/04, lehmancj@........... writes:

Recently I saw reference to= an article on the parameters of "Earth Hum"---Real long period waves of 4 t= o 5 minutes.  This translated to a frequency 16 octives below (256 Hz)=20= middle C.  These waveforms are detectable seemingly anywhere on the Ear= th's surface.
  The article can be found in the Sept. 30th '04 issue of = Nature magazine, but didn't give much help in the recording mechanics of= such long waveforms. Can anyone simplify an explanation of how these waves=20= are detected?


Hi Jim,

      The original Streckeisen STS-1 seis= mometer had a period of ~850 sec and used a LVDT feedback detector. The Kine= metrics FBA-23 accelerometer works from DC up. The Guralp CMG-3 can work at=20= 360 sec and uses a capacitative detector. It is also possible to use a seism= ometer with a shorter period and extend the period using digital signal proc= essing, by a factor of up to about 10. Other methods which may be used for s= ensing very long period signals include extensometers and tiltmeters, often=20= placed deep underground in mine shafts to avoid surface noise.=20
      For more information, I suggest you= read 'The leaf spring seismometer: design and performance' by E Wielandt an= d G Streckeisen, Bull Seis Soc America, Vol 72, No. 6, pp2349-2367, 1982. La= Coste came up with an infinite period spring design back in 1934. Basically,= you start with a longish period and then apply a feedback loop which define= s the response - the S&G seismometers also did that with a 1 sec pendulu= m - see psn account.=20
      There was an Iris conference at Gra= nlibakken last March discussing long period instrument development. See http= ://www.iris.edu/stations/seisWorkshop04/ The papers are mostly available on=20= line.
      I hope that this is of some help.=20

      Regards,

      Chris Chapman
Subject: Re: Earth Hum! From: "Connie and Jim Lehman" lehmancj@........... Date: Tue, 26 Oct 2004 10:17:38 -0400 Thanks Chris-- Well Done, I was wondering if long base tiltmeters might = be employed. Thanks for the references-- Jim Lehman ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Monday, October 25, 2004 10:23 PM Subject: Re: Earth Hum! In a message dated 24/10/04, lehmancj@........... writes:=20 Recently I saw reference to an article on the parameters of "Earth = Hum"---Real long period waves of 4 to 5 minutes. This translated to a = frequency 16 octives below (256 Hz) middle C. These waveforms are = detectable seemingly anywhere on the Earth's surface.=20 The article can be found in the Sept. 30th '04 issue of Nature = magazine, but didn't give much help in the recording mechanics of such = long waveforms. Can anyone simplify an explanation of how these waves = are detected? Hi Jim,=20 The original Streckeisen STS-1 seismometer had a period of ~850 = sec and used a LVDT feedback detector. The Kinemetrics FBA-23 = accelerometer works from DC up. The Guralp CMG-3 can work at 360 sec and = uses a capacitative detector. It is also possible to use a seismometer = with a shorter period and extend the period using digital signal = processing, by a factor of up to about 10. Other methods which may be = used for sensing very long period signals include extensometers and = tiltmeters, often placed deep underground in mine shafts to avoid = surface noise.=20 For more information, I suggest you read 'The leaf spring = seismometer: design and performance' by E Wielandt and G Streckeisen, = Bull Seis Soc America, Vol 72, No. 6, pp2349-2367, 1982. LaCoste came up = with an infinite period spring design back in 1934. Basically, you start = with a longish period and then apply a feedback loop which defines the = response - the S&G seismometers also did that with a 1 sec pendulum - = see psn account.=20 There was an Iris conference at Granlibakken last March = discussing long period instrument development. See = http://www.iris.edu/stations/seisWorkshop04/ The papers are mostly = available on line.=20 I hope that this is of some help.=20 Regards,=20 Chris Chapman=20
Thanks Chris--  Well Done, I was = wondering if=20 long base tiltmeters might be employed.  Thanks for the=20 references--
  Jim Lehman
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Monday, October 25, 2004 = 10:23=20 PM
Subject: Re: Earth Hum!

In a=20 message dated 24/10/04, lehmancj@........... writes: =

Recently I saw reference to an article on the parameters = of=20 "Earth Hum"---Real long period waves of 4 to 5 minutes.  This=20 translated to a frequency 16 octives below (256 Hz) middle C. =  These=20 waveforms are detectable seemingly anywhere on the Earth's surface.=20
  The article can be found in the Sept. 30th '04 issue = of=20 Nature magazine, but didn't give much help in the recording = mechanics=20 of such long waveforms. Can anyone simplify an explanation of how = these=20 waves are detected?


Hi Jim,=20

      The original Streckeisen = STS-1=20 seismometer had a period of ~850 sec and used a LVDT feedback = detector. The=20 Kinemetrics FBA-23 accelerometer works from DC up. The Guralp CMG-3 = can work=20 at 360 sec and uses a capacitative detector. It is also possible to = use a=20 seismometer with a shorter period and extend the period using digital = signal=20 processing, by a factor of up to about 10. Other methods which may be = used for=20 sensing very long period signals include extensometers and tiltmeters, = often=20 placed deep underground in mine shafts to avoid surface noise.=20
      For more information, I = suggest you=20 read 'The leaf spring seismometer: design and performance' by E = Wielandt and G=20 Streckeisen, Bull Seis Soc America, Vol 72, No. 6, pp2349-2367, 1982. = LaCoste=20 came up with an infinite period spring design back in 1934. Basically, = you=20 start with a longish period and then apply a feedback loop which = defines the=20 response - the S&G seismometers also did that with a 1 sec = pendulum - see=20 psn account.
      There was an Iris = conference at Granlibakken last March discussing long period = instrument=20 development. See http://www.iris.edu/stations/seisWorkshop04/ The = papers are=20 mostly available on line.
      I = hope that=20 this is of some help. =

      Regards,=20

      Chris Chapman
=20
Subject: Reference to a commercially available Magnet assembly & photodiode From: "Meredith Lamb" meredithlamb@............. Date: Thu, 18 Nov 2004 23:49:43 -0700 Hi all, If you're contemplating building a (?type) seismo, you might check out acouple items I see at the web site for the "Electronic Goldmine" surplus in Arizona, USA. http://www.goldmine-elec-products.com Item #G13502 is a two piece magnet on what seems to be on a "soft iron" (purer iron) bracket. Its "looks like" a old giant computer read head unit, but could have been used for a early tape drive speed brake/dampening control. Its on sale for $3.95 till 11/30/04. I estimate its rating is ~N35. These normally sell for ~$9-$12 each. This is definitely a finger/skin/bone pinching/breaking dangerious item; but good for small diameter copper wound sensing coils that pass over the two magnet junction. It might work for copper plate dampening. Two assemblys facing each other and spaced with threaded bolts/nuts would probably do either function of sensing/dampening and/or both at once...or with additional assemblys for whatever function....but....be very careful in doing this...use wood inbetween for initial "gap" spacing! The soft iron bracket material seems to be very unusual ....its very hard to find, normally very expensive material in itself, and does a excellent job with the magnets field. Forcefield/ Wonder magnet souce has sold gobs of these in the past; but, has none at the present. Item #G13644, is a BPW33 photodiode (photo-generative). Four for $1, or other higher quanities is available. I think alot of people in the "know", rate this item as very good. For a obvious light sensing, mass movement seismo; normally used in a electronic "bridge" pair. Unfortunately there is no web page photo. For a fast review, use the "product Search" box, and item code in the upper left of the web page for the Electronic Goldmine web page reference. I've bought from this source with no trouble; but seen web search engine complaints too. Take care, Meredith Lamb

Hi all,
 
If you're contemplating building a (?type) seismo, you might check out acouple items
I see at the web site for the "Electronic Goldmine" surplus in Arizona, USA.
 
http://www.goldmine-elec-products.com
 
Item #G13502 is a two piece magnet on what seems to be on a "soft iron" (purer iron)
bracket.  Its "looks like" a old giant computer read head unit, but could have been
used for a early tape drive speed brake/dampening control.  Its on sale for $3.95 till
11/30/04.  I estimate its rating is ~N35.  These normally sell for ~$9-$12 each.   This
is definitely a finger/skin/bone pinching/breaking dangerious item; but good for
small diameter copper wound sensing coils that pass over the two magnet junction.
It might work for copper plate dampening.  Two assemblys facing each other and
spaced with threaded bolts/nuts would probably do either function of sensing/dampening
and/or both at once...or with additional assemblys for whatever function....but....be
very careful in doing this...use wood inbetween for initial "gap" spacing!  The soft iron
bracket material seems to be very unusual ....its very hard to find, normally very
expensive material in itself, and does a excellent job with the magnets field.  Forcefield/
Wonder magnet souce has sold gobs of these in the past; but, has none at the present.
 
Item #G13644, is a BPW33 photodiode (photo-generative).  Four for $1, or other
higher quanities is available.  I think alot of people in the "know", rate this item as
very good.  For a obvious light sensing, mass movement seismo; normally used in
a electronic "bridge" pair.   Unfortunately there is no web page photo.
 
For a fast review, use the "product Search" box, and item code in the upper left of the
web page for the Electronic Goldmine web page reference.
 
I've bought from this source with no trouble; but seen web search engine complaints
too.
 
Take care, Meredith Lamb
 
 

Subject: Re: Reference to a commercially available Magnet assembly & photodiode From: ChrisAtUpw@....... Date: Fri, 19 Nov 2004 09:14:41 EST In a message dated 19/11/2004, meredithlamb@............. writes: Item #G13644, is a BPW33 photodiode (photo-generative). Four for $1, or other higher quanities is available. I think alot of people in the "know", rate this item as very good. Hi All, This is a good low leakage 2.71 mm square photodiode in a clear plastic case. See _http://www.osram.convergy.de/upload/documents/bulkload/infrared/bpw33.pdf_ (http://www.osram.convergy.de/upload/documents/bulkload/infrared/bpw33.pdf) Regards, Chris Chapman
In a message dated 19/11/2004, meredithlamb@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Item #G13644, is a BPW33 photodiode (photo-generative).  Four fo= r=20 $1, or other
higher quanities is available.  I think alot of people in the=20 "know", rate this item as
very good. 
Hi All,
 
    This is a good low leakage 2.71 mm square=20 photodiode in a clear plastic case. See http://www.osram.convergy.de/upload/documents/bulkload/infrared/bpw33= ..pdf 
 
    Regards,
 
    Chris Chapman
Subject: Seismoscope From: "Edward Ianni" edwianni1@........... Date: Thu, 2 Dec 2004 21:24:50 -0500 Hi Gang; Seismoscope on ebay.....6128658309. Ed Ianni
Hi Gang;
     Seismoscope on = ebay.....6128658309.
Ed Ianni
Subject: RE: Seismoscope From: "Meredith Lamb" meredithlamb@............. Date: Thu, 2 Dec 2004 23:22:10 -0700 Actually...........these units are antique, and rarely used anywhere anymore, as all they do is put a needle (track) over a smoked glass curved surface and make of record of a nearby (fairly strong) quakes gyrations. They were very well made at the time (~late 1950's, 1960's) However.........they DO present a possible IDEA route for a bi-directional horizontal seismometer approach. If I remember right; they are essentially a hanging mass (S-G = Shackleford- Gunderson type) suspension. It "might" be possible to derive signals with capacitance or displacement light sensors. Dampening could be accomodated via magnetic induction eddy currents...say with the mass being copper, and magnets on the seismo platform adjacent nearby. I'am not suggesting that one buy the seismoscope and convert such; it probably isn't worth the cost effort. The basic idea is very old; but, no one has done such (S-G bi-directional sensing) that I'am aware of. "S-G's" usually have almost nill minor tilt problems compared to other "hanging gate" type construction seismo's. S-G's need a sturdy frame support mechanism/assembly. Obviously they are a "gravity zeroing" instrument. The hanging mass "natural period" will be short in itself; but, with a displacement sensor/s, one should see the "L" phase (somewhat attenuated) longer quake periods results readily. One might need a unspecified thickness of the mass hanging wire; to limit any (air current) mass rotation that could occur with too thin a diameter of smaller gauge wire. Take care, Meredith Lamb ----- Original Message ----- From: Edward Ianni To: psn-l@.............. Sent: 12/2/2004 7:24:49 PM Subject: [Norton AntiSpam] Seismoscope Hi Gang; Seismoscope on ebay.....6128658309. Ed Ianni
Actually...........these units are antique, and rarely used anywhere anymore, as all they do
is put a needle (track) over a smoked glass curved surface and make of record of a nearby
(fairly strong) quakes gyrations.  They were very well made at the time (~late 1950's, 1960's)
 
However.........they DO present a possible IDEA route for a bi-directional horizontal seismometer
approach.  If I remember right; they are essentially a hanging mass (S-G = Shackleford-
Gunderson type) suspension.  It "might" be possible to derive signals with capacitance
or displacement light sensors.  Dampening could be accomodated via magnetic induction
eddy currents...say with the mass being copper, and magnets on the seismo platform
adjacent nearby.  I'am not suggesting that one buy the seismoscope and convert such;
it probably isn't worth the cost effort.
 
The basic idea is very old; but, no one has done such (S-G bi-directional sensing) that I'am
aware of.
 
"S-G's" usually have almost nill minor tilt problems compared to other "hanging gate" type
construction seismo's.  S-G's need a sturdy frame support mechanism/assembly.
Obviously they are a "gravity zeroing" instrument.
 
The hanging mass "natural period" will be short in itself; but, with a displacement sensor/s,
one should see the "L" phase (somewhat attenuated) longer quake periods results readily. 
 
One might need a unspecified thickness of the mass hanging wire; to limit any (air current)
mass rotation that could occur with too thin a diameter of smaller gauge wire.   
 
Take care, Meredith Lamb
 
----- Original Message -----
From: Edward Ianni
To: psn-l@..............
Sent: 12/2/2004 7:24:49 PM
Subject: [Norton AntiSpam] Seismoscope

Hi Gang;
     Seismoscope on ebay.....6128658309.
Ed Ianni
Subject: RE: Seismoscope From: "Doug Crice" dcrice@............ Date: Fri, 3 Dec 2004 04:51:07 -0800 Actually, these units already have magnetic induction damping. You can see the curved aluminum disk in the photo, and there's a strong, adjustable magnet underneath. Doug Crice Wireless Seismic http://www.wirelessSeismic.com 12996 Somerset Drive phone 1-530-274-4445 Grass Valley, CA 95945 USA fax 1-530-274-4446 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Meredith Lamb Sent: Thursday, December 02, 2004 10:22 PM To: psn-l@.............. Subject: RE: Seismoscope Actually...........these units are antique, and rarely used anywhere anymore, as all they do is put a needle (track) over a smoked glass curved surface and make of record of a nearby (fairly strong) quakes gyrations. They were very well made at the time (~late 1950's, 1960's) However.........they DO present a possible IDEA route for a bi-directional horizontal seismometer approach. If I remember right; they are essentially a hanging mass (S-G = Shackleford- Gunderson type) suspension. It "might" be possible to derive signals with capacitance or displacement light sensors. Dampening could be accomodated via magnetic induction eddy currents...say with the mass being copper, and magnets on the seismo platform adjacent nearby. I'am not suggesting that one buy the seismoscope and convert such; it probably isn't worth the cost effort. The basic idea is very old; but, no one has done such (S-G bi-directional sensing) that I'am aware of. "S-G's" usually have almost nill minor tilt problems compared to other "hanging gate" type construction seismo's. S-G's need a sturdy frame support mechanism/assembly. Obviously they are a "gravity zeroing" instrument. The hanging mass "natural period" will be short in itself; but, with a displacement sensor/s, one should see the "L" phase (somewhat attenuated) longer quake periods results readily. One might need a unspecified thickness of the mass hanging wire; to limit any (air current) mass rotation that could occur with too thin a diameter of smaller gauge wire. Take care, Meredith Lamb ----- Original Message ----- From: Edward Ianni To: psn-l@.............. Sent: 12/2/2004 7:24:49 PM Subject: [Norton AntiSpam] Seismoscope Hi Gang; Seismoscope on ebay.....6128658309. Ed Ianni

Actually, these units already have magnetic induction damping. You can see the curved aluminum disk in the = photo, and there’s a strong, adjustable magnet = underneath.

 

Doug Crice

Wireless Seismic           = http://www.wirelessSeismic.com

12996 Somerset Drive           &n= bsp;    phone 1-530-274-4445

Grass Valley,  CA  = 95945  USA    fax 1-530-274-4446

 

-----Original = Message-----
From: = psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Meredith Lamb
Sent: Thursday, December = 02, 2004 10:22 PM
To: = psn-l@..............
Subject: RE: = Seismoscope

 

Actually...........these units are antique, and rarely used anywhere anymore, as all they = do

is put a needle = (track) over a smoked glass curved surface and make of record of a = nearby

(fairly strong) = quakes gyrations.  They were very well made at the time (~late = 1950's, 1960's)

 

However.........they DO present a possible IDEA route for a bi-directional horizontal = seismometer

approach.  = If I remember right; they are essentially a hanging mass = (S-G =3D Shackleford-

Gunderson type) suspension.  It "might" be possible to derive signals = with capacitance

or displacement = light sensors.  Dampening could be accomodated via magnetic = induction

eddy = currents...say with the mass being copper, and magnets on the seismo = platform

adjacent = nearby.  I'am not suggesting that one buy the seismoscope and convert = such;

it probably isn't = worth the cost effort.

 

The basic idea is = very old; but, no one has done such (S-G bi-directional sensing) that = I'am

aware = of.

 

"S-G's" = usually have almost nill minor tilt problems compared to other = "hanging gate" type

construction = seismo's.  S-G's need a sturdy frame support mechanism/assembly.

Obviously they = are a "gravity zeroing" instrument.

 

The hanging mass "natural period" will be short in itself; but, with a = displacement sensor/s,

one should see = the "L" phase (somewhat attenuated) longer quake periods results = readily. 

 

One might need a unspecified thickness of the mass hanging wire; to limit any (air = current)

mass rotation = that could occur with too thin a diameter of smaller gauge = wire.   

 

Take care, = Meredith Lamb

 

----- Original = Message -----

From: Edward Ianni

To: = psn-l@..............

=

Sent: 12/2/2004 7:24:49 PM

Subject: [Norton AntiSpam] Seismoscope

 

Hi Gang;

     = Seismoscope on ebay.....6128658309.

Ed Ianni

Subject: ebay auctions From: BOB BARNS royb1@........... Date: Fri, 03 Dec 2004 10:02:16 -0500 Hi gang, GEOMETRICS ES-2401 EXPORATION SEISMOGRAPH EC&G ES2401 Item number: 3857688672 ends Dec 9 Also, GEOMETRICS ES-2401 EXPORATION SEISMOGRAPH EC&G ES2401 Item number: 3857688672 ends Dec 11 This is one of Bolt's books. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ebay books From: BOB BARNS royb1@........... Date: Sat, 11 Dec 2004 13:50:46 -0500 Hi gang, There is a bunch of books on ebay about seismology. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Wielandt's "inverse filter" or integrator From: "David H. Youden" dyouden@............. Date: Mon, 13 Dec 2004 07:11:26 -0500 Good morning all, I am looking for some enlightenment on the subject circuit. I know just enough about it to be dangerous and not enough to understand what exactly it does and how to select the corner frequency of the high pass filter. I have not been able to obtain a copy of Wielandt's paper "Noise in Electronic Seismograph Systems", so if anyone has an electronic copy (in english) I would appreciate a copy. Short of that, can anyone provide an explanation of how this thing works, and what the alternatives to it might be. I understand that the output of the high pass filter is fed back to the input amplifier and subtracted from the input signal, but doesn't the phase shift in the filter prevent this from working as Allan Coleman describes in his papers? Thanks for any help you may provide Dave Youden __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Wielandt's "inverse filter" or integrator (long) From: Brett Nordgren Brett3kg@............. Date: Wed, 15 Dec 2004 17:54:23 -0500 Dave, Sorry, I don't have a copy of the "Noise" paper. If Chris Chapman is still monitoring the list, he might be able to help you find it. I know he'd been working to acquire many of the old journal articles. Enlightenment is good. Feedback systems are some of the more non-intuitive things you're likely to come across. To tell the truth, when I was first doing feedback design, I think it was a couple of years before I could honestly claim that I had a "feel" for what was going on. One general comment on why feedback seismos exist.... Starting with a spring-mass which has a position sensor and some means for applying force-feedback, the feedback is used to *reduce* and shape the frequency response to predictably match the shape you want. There is a fairly standard set of seismo. frequency-response curves that seem to be in common use by seismologists for different purposes. In most cases, around here, the Velocity Broad Band response seems to be the most common. The purpose of having feedback is to tightly control the instrument response (at the expense of sensitivity). However in electronic seismo. systems, high sensitivity is quite easy to get. The more fundamental issue will usually be instrument noise. The "inverse filter" you refer to was one of many terms coined in the early days of feedback seismometers as designers were first putting together and publishing the concept. A more accurate name might be "one of those things you need in order to make the frequency response what you want", though I admit, it is a little lacking in elegance and brevity. His choice for the term probably comes from the fact that when *any* element is put in the feedback path, the overall instrument response that results will tend to be the inverse of that element's frequency response. That fact is fundamental to *all* feedback designs. If you haven't spent time with them, I would very much recommend Wielandt's articles "Seismic Sensors and their Calibration " online at http://www.geophys.uni-stuttgart.de/seismometry/man_html/index.html and "Seismometry", located at http://www.geophys.uni-stuttgart.de/seismometry/hbk_html/index.html In particular, the sections on force balance seismometers should be helpful. These are much more understandable and technically refined than the early journal articles, which often were not easy to follow. And you can try my Web site downloads index at http://bnordgren.org/seismo/index.html The files "feedback", "complex" and particularly "loop3" might be of interest. Also, today, I put a draft copy of "loop4" on the site, but haven't put it in the index yet. You can access it directly at http://bnordgren.org/seismo/loop4.pdf It is considerably improved from "loop3" (and somewhat larger). These relate to an analysis of the feedback loop of S-T Morrissey's STM-8 leaf spring vertical. Its loop design is very similar to those of the commercial VBB instruments. If you can follow the math, great, but there's still a lot there that should be helpful even neglecting the math details. Hope these help. Brett At 07:11 AM 12/13/2004 -0500, you wrote: >Good morning all, > >I am looking for some enlightenment on the subject circuit. I know just >enough about it to be dangerous and not enough to understand what exactly >it does and how to select the corner frequency of the high pass filter. I >have not been able to obtain a copy of Wielandt's paper "Noise in >Electronic Seismograph Systems", so if anyone has an electronic copy (in >english) I would appreciate a copy. Short of that, can anyone provide an >explanation of how this thing works, and what the alternatives to it might be. > >I understand that the output of the high pass filter is fed back to the >input amplifier and subtracted from the input signal, but doesn't the >phase shift in the filter prevent this from working as Allan Coleman >describes in his papers? > >Thanks for any help you may provide > >Dave Youden __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Wielandt's "inverse filter" or integrator (long) From: "David H. Youden" dyouden@............. Date: Thu, 16 Dec 2004 17:17:29 -0500 Brett, That's an impressive piece of work that you have done there. I have downloaded and printed the files of interest and will start reading them tonight. Thanks so much for your help. Yes, Chris is still around and says that he will try to get the Wielandt paper on noise. I have read the Stuttgart papers and find them very helpful. Thanks again for your help. Dave... Brett Nordgren wrote: > Dave, > > Sorry, I don't have a copy of the "Noise" paper. If Chris Chapman is > still monitoring the list, he might be able to help you find it. I > know he'd been working to acquire many of the old journal articles. > > Enlightenment is good. Feedback systems are some of the more > non-intuitive things you're likely to come across. To tell the truth, > when I was first doing feedback design, I think it was a couple of > years before I could honestly claim that I had a "feel" for what was > going on. > > One general comment on why feedback seismos exist.... Starting with a > spring-mass which has a position sensor and some means for applying > force-feedback, the feedback is used to *reduce* and shape the > frequency response to predictably match the shape you want. There is > a fairly standard set of seismo. frequency-response curves that seem > to be in common use by seismologists for different purposes. In most > cases, around here, the Velocity Broad Band response seems to be the > most common. The purpose of having feedback is to tightly control the > instrument response (at the expense of sensitivity). However in > electronic seismo. systems, high sensitivity is quite easy to get. > The more fundamental issue will usually be instrument noise. > > The "inverse filter" you refer to was one of many terms coined in the > early days of feedback seismometers as designers were first putting > together and publishing the concept. A more accurate name might be > "one of those things you need in order to make the frequency response > what you want", though I admit, it is a little lacking in elegance and > brevity. His choice for the term probably comes from the fact that > when *any* element is put in the feedback path, the overall instrument > response that results will tend to be the inverse of that element's > frequency response. That fact is fundamental to *all* feedback designs. > > If you haven't spent time with them, I would very much recommend > Wielandt's articles "Seismic Sensors and their Calibration " online at > http://www.geophys.uni-stuttgart.de/seismometry/man_html/index.html > and "Seismometry", located at > http://www.geophys.uni-stuttgart.de/seismometry/hbk_html/index.html > In particular, the sections on force balance seismometers should be > helpful. These are much more understandable and technically refined > than the early journal articles, which often were not easy to follow. > > And you can try my Web site downloads index at > http://bnordgren.org/seismo/index.html > The files "feedback", "complex" and particularly "loop3" might be of > interest. Also, today, I put a draft copy of "loop4" on the site, but > haven't put it in the index yet. You can access it directly at > http://bnordgren.org/seismo/loop4.pdf > It is considerably improved from "loop3" (and somewhat larger). These > relate to an analysis of the feedback loop of S-T Morrissey's STM-8 > leaf spring vertical. Its loop design is very similar to those of the > commercial VBB instruments. If you can follow the math, great, but > there's still a lot there that should be helpful even neglecting the > math details. > > Hope these help. > > Brett > > At 07:11 AM 12/13/2004 -0500, you wrote: > >> Good morning all, >> >> I am looking for some enlightenment on the subject circuit. I know >> just enough about it to be dangerous and not enough to understand >> what exactly it does and how to select the corner frequency of the >> high pass filter. I have not been able to obtain a copy of Wielandt's >> paper "Noise in Electronic Seismograph Systems", so if anyone has an >> electronic copy (in english) I would appreciate a copy. Short of >> that, can anyone provide an explanation of how this thing works, and >> what the alternatives to it might be. >> >> I understand that the output of the high pass filter is fed back to >> the input amplifier and subtracted from the input signal, but doesn't >> the phase shift in the filter prevent this from working as Allan >> Coleman describes in his papers? >> >> Thanks for any help you may provide >> >> Dave Youden > > > > > __________________________________________________________ > > 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: all the best for the new year From: Mark Robinson mark.robinson@............... Date: Sat, 01 Jan 2005 05:55:34 +1300 Hi everybody, The phrase "rock my world" just went out of fashion. I wonder if there is any software about that can monitor a seismograph signal, pick P and S arrivals, calculate magnitude, location, tsunami threat level, tsunami time of arrival over a defined coastline map, automatically consult and vote with other neighbouring stations on the threat level, and flip a bit on a serial or parallel port if everything is looking really ugly, perhaps morse code "TS" ? You know, all the bells and whistles. My coding skills suck these days, but I'll contribute whatever I can to such a project if it doesn't exist, and if anyone else wants to, purely in my own interests, living as I do on seaside sand dunes on an active part of the intersection of the pacific and australien plates. Enjoy your friendships in celebrating the New Year. Mark Robinson ------------- 01 Jan 1853 The strongest known earthquake in the New Plymouth area. 6.5. 01 Jan 1854 Sir James George Frazer, author and scholar, born. 01 Jan 1867 First Chinese immigrants to NZ arrive at Hokitika. 01 Jan 1897 Author E M Forster born. 01 Jan 1950 Castro seizes power in Cuba, Batista flees. 01 Jan 1984 Mimiwhangata Marine Park established. 01 Jan 1991 Presidents Bush and Gorbachev condemn Iraqi conquest of Kuwait in New Year's messages. There's a mainframe wrecker about 70km from here that sells semiconductor relays for $NZ3 each. These are easy to drive off a port pin. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ebay auction From: BOB BARNS royb1@........... Date: Fri, 31 Dec 2004 13:02:06 -0500 8" chart mover for seismograph Item number: 3864207955 ends Jan.6 Happy New Year! Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: all the best for the new year From: sismos@.............. Date: Fri, 31 Dec 2004 14:03:54 +0000 Hello Mark, Most of what you describe is quite possible. I think that the all the PSN stations that have permanent connections to the internet accurate time and a known locations could contribute. It would also help if the polarity of the signal was correct and finally if the transfer function was known. I think we could locate events with seconds with a loose network. All of the code is written and free all we have to do is assemble it and make it work. I'm interested any other taker on such a project. I was going to propose it in a week or so anyway. Happy New Year to all. Best regards, angel PS Mark, tell me more about the relays, I might want a bunch. Friday, December 31, 2004, 4:55:34 PM, you wrote: MR> Hi everybody, MR> The phrase "rock my world" just went out of fashion. MR> I wonder if there is any software about that can monitor a seismograph signal, MR> pick P and S arrivals, calculate magnitude, location, tsunami threat level, MR> tsunami time of arrival over a defined coastline map, automatically consult and MR> vote with other neighbouring stations on the threat level, and flip a bit on a MR> serial or parallel port if everything is looking really ugly, perhaps morse code MR> "TS" ? You know, all the bells and whistles. MR> My coding skills suck these days, but I'll contribute whatever I can to such a MR> project if it doesn't exist, and if anyone else wants to, purely in my own MR> interests, living as I do on seaside sand dunes on an active part of the MR> intersection of the pacific and australien plates. MR> There's a mainframe wrecker about 70km from here that sells semiconductor relays MR> for $NZ3 each. These are easy to drive off a port pin. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: all the best for the new year From: Mark Robinson mark.robinson@............... Date: Sat, 01 Jan 2005 09:00:17 +1300 sismos@.............. wrote: > All of the code is written and free all we have to do is assemble it > and make it work. I'm interested any other taker on such a project. > I was going to propose it in a week or so anyway. > > PS Mark, tell me more about the relays, I might want a bunch. Hi Angel, Thanks for the encouragement. Here's the bag of relays from my collection : http://zl2tod.net/pix/200501010830-electronic-relays.jpg As you can see they range in switching capacity and sensitivity. I think they are all zero crossing switched and optoisolated to 5kV. You will find datasheets for some of them on the net. The ones that boast 3-32V control will happily work directly off a port pin, and switch easily enough mains AC to run an obnoxiously loud siren or whatever. The Cat Man / New Age Materials is the computer wrecker, you can look at their website at http://www.catman.co.nz/. I reckon last time I was there there were about 50-150 in the bucket, including a number of less switching capacity than those in the picture. That was a few months ago though. I envision a system consisting of a suitable UPS, compact wideband seismic sensor (better work without this as I don't have one here) with versatile networking options. Any old laptop running a bootable linux or *BSD CD image is attractive. regards Mark __________________________________________________________ Public Seismic Network Mailing List (PSN-L)