PSN-L Email List Message
Subject: Re: P & S Markers Location, WQ
From: "Larry Cochrane" lcochrane@..............
Date: Sun, 2 Jan 2005 20:09:26 -0800
Happy New Year Everyone,
You won't see a P or S wave after ~11000 km. This is because the earths core
creates a shadow of the P wave and the outer core a shadow of the S wave. If
you do a google search you can find more information. This page as a nice
image showing what going on with the P and S waves. The IAPS91 travel-time
table has information that goes past 11000km so WinQuake will place the P
and S marks in the window, but they are meaningless do to the shadowing
Redwood City, PSN
----- Original Message -----
From: "Steve Jones"
Sent: Sunday, January 02, 2005 5:39 PM
Subject: P & S Markers Location, WQ
> Hi Larry,
> I have a question re: Winquake, and the P&S Marker location. I recorded
> 12/26/04 M9.0 event (along with everybody else) and the later 01/01/05
> event off Sumatra. On both of these, I cannot get the P & S marker
> locations on the record to align with the first arrival of the P and S
> at my location. For each event, Winquake does calculate the distance to
> location from the epicenter at 15000+ Km.
> I am running the WQ version 2.9, if that info helps. I have very
> checked my timing and event location data plugged into Winquake. Do you
> have any idea why the P & S calculation seems to be off?
> If need be, I can email the two event records to you for your examination.
> Steve Jones
> Huntsville, Alabama
> 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)
[ Top ]
[ Back ]
[ Home Page ]