HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Hough, S. E. Search for Related Content GeoRef GeoRef Citation

Empirical Green's Function Analysis of Recent Moderate Events in California

United States Geological Survey
Pasadena, Californi
(S.E.H.)

I use seismic data from portable digital stations and the broadband Terrascope network in southern California to investigate radiated earthquake source spectra and discuss the results in light of previous studies on both static stress drop and apparent stress. Applying the empirical Green's function (EGF) method to two sets of M 4–6.1 events, I obtain deconvolved source-spectra estimates and corner frequencies. The results are consistent with an ² source model and constant Brune stress drop. However, consideration of the raw spectral shapes of the largest events provides evidence for a high-frequency decay more shallow than ². The intermediate (f^–1) slope cannot be explained plausibly with attenuation or site effects and is qualitatively consistent with a model incorporating directivity effects and a fractional stress-drop rupture process, as suggested by Haddon (1996). However, the results obtained in this study are not consistent with the model of Haddon (1996) in that the intermediate slope is not revealed with EGF analysis. This could reflect either bandwidth limitations inherent in EGF analysis or perhaps a rupture process that is not self-similar. I show that a model with an intermediate spectral decay can also reconcile the apparent discrepancy between the scaling of static stress drop and that of apparent stress drop for moderate-to-large events.

This article has been cited by other articles:

				G. Calderoni, A. Rovelli, G. Cultrera, R. M. Azzara, and G. Di Giulio Assessment of Ground Motion in Palermo, Italy, during the 6 September 2002 Mw 5.9 Earthquake Using Source Scaling Law Bulletin of the Seismological Society of America, December 1, 2005; 95(6): 2342 - 2363. [Abstract] [Full Text] [PDF]