PSN-L Email List Message

Subject: OLDER SEISMOMETERS FOR SALE
From: "James Allen" jcallen1@...........
Date: Mon, 30 Mar 2009 21:15:37 -0700


I met a gentleman via email, Matt, that has a number of older =
seismometers for sale, with some on EBay, a Kinemetrics vertical and =
horizontal and a ranger.  One of the item numbers is 110369876034, that =
listing will take you to the other two he has.  He also would like help =
in identifying a number of other seismometers he has that he has not =
listed as yet.  The URL for the pictures is =
http://s271.photobucket.com/albums/jj139/shostang/Seismology/  He would =
really appreciate list members help in identifying the units he has.
  ----- Original Message -----=20
  From: Bob Hancock=20
  To: psn-l@.................
  Sent: Monday, March 30, 2009 11:58 AM
  Subject: Re: Rayleigh and Love waves


  Hi Martin -


  With two horizontal channels, you an use the amplitude of the P wave =
arrivals to determine a great circle path through your station.  However =
that is insufficient information for you to determine which of two =
inbound headings the signal came from.  For that information, you need =
the initial motion on the P waves from both horizontal channels and the =
vertical channel. =20


  Bob Hancock




  On Mar 30, 2009, at 1:53 AM, Tangazazen@....... wrote:


    Hi Bob,

      I was most interested in your surface wave comments.Here in =
England local earth quakes are rare so most events detected are =
teleseismic.

    I have a pendulum seismometer that resolves both X and Y axis =
components independently ( broadband 50 seconds ). If I plot the N-S =
verses E-W components during the first few minutes of a teleseismic =
event one gets a form that indicates the direction of arrival. The =
Svalbard event you mention shows a form whose major axis is along the  =
NNW-SSE, consistent with it's location relative to England. For the =
recent Tonga event M7.8, the X-Y plot has a majors axis virtually north- =
south consistent with the shortest path though China, Siberia and the =
north pole.
    Inspection of the individual seismographs show an initial strong =
radial component relative to the transverse as would be expected.

    The last local event was  2 years ago ( M 4.7 ) so I have to make =
the most of teleseismic events!


    Regards Martin =20








I met a gentleman via email, = Matt, that has a=20 number of older seismometers for sale, with some on EBay, a Kinemetrics = vertical=20 and horizontal and a ranger.  One of the item numbers is = 110369876034, that=20 listing will take you to the other two he has.  He also would like = help in=20 identifying a number of other seismometers he has that he has not listed = as=20 yet.  The URL for the pictures is ht= tp://s271.photobucket.com/albums/jj139/shostang/Seismology/ =20 He would really appreciate list members help in identifying the units he = has.
----- Original Message -----
From:=20 Bob = Hancock=20
To: psn-l@..............
Sent: Monday, March 30, 2009 = 11:58=20 AM
Subject: Re: Rayleigh and Love=20 waves

Hi Martin -

With two horizontal channels, you an use the amplitude of the P = wave=20 arrivals to determine a great circle path through your station. =  However=20 that is insufficient information for you to determine which of two = inbound=20 headings the signal came from.  For that information, you need = the=20 initial motion on the P waves from both horizontal channels and the = vertical=20 channel.  

Bob Hancock


On Mar 30, 2009, at 1:53 AM, Tangazazen@....... = wrote:
Hi Bob,
 
  I was most interested in your surface wave comments.Here = in=20 England local earth quakes are rare so most events detected are=20 teleseismic.
 
I have a pendulum seismometer that resolves both X and Y axis=20 components independently ( broadband 50 seconds ). If I plot = the N-S=20 verses E-W components during the first few minutes of a teleseismic = event=20 one gets a form that indicates the direction of arrival. The = Svalbard event=20 you mention shows a form whose major axis is along = the  NNW-SSE,=20 consistent with it's location relative to England. For = the recent=20 Tonga event M7.8, the X-Y plot has a majors axis virtually = north-=20 south consistent with the shortest path though China, Siberia = and the=20 north pole.
Inspection of the individual seismographs show an initial = strong radial=20 component relative to the transverse as would be expected.
 
The last local event was  2 years ago ( M 4.7 ) so I have = to make=20 the most of teleseismic events!
 
 
Regards=20 Martin  

=

[ Top ] [ Back ] [ Home Page ]