Bulletin of the Seismological Society of America; August 2007; v. 97; no. 4;
p. 1196-1203; DOI: 10.1785/0120060028
© 2007 Seismological Society of America
Use of Time-Deformation Methods to Discriminate between Earthquakes and Explosions on the Basis of Lg Alone
Wayne A. Woodward1,
Henry L. Gray1,
Indra Gupta2 and
James R. Haney1
1 Department of Statistical Science
Southern Methodist University
Dallas, Texas 75275-4035
(W.A.W., H.L.G., J.R.H.)
2 Multimax, Inc.
1441 McCormick Drive
Largo, Maryland 20774-5323
(I.G.)
In this article we introduce the use of time-transformation methods for
analyzing signals with time-varying frequencies. We show that these techniques
can be usefully applied to the Lg waves of earthquakes and explosions
for purposes of deriving discriminants based on the Lg wave alone.
Preliminary examination of the Lg waves from 10 earthquakes and 10
explosions recorded at the Mina, Nevada (MNV), station shows that
frequencies are varying (decreasing) more systematically with time for
explosions than for earthquakes. Use of a proposed discriminant produced
excellent discrimination between the earthquakes and explosions analyzed.
Copyright © 2009 by Seismological Society of America