thumbnail

Energy-to-moment ratios for damaging intraslab earthquakes: preliminary results on a few case studies

Open-File Report 2002-328

By:
and

Links

Abstract

We use the energy-to-moment ratio, as introduced by Newman and Okal [1998] to examine the source characteristics of normal-faulting intraslab earthquakes, compared to nearby interplate thrust events, based on recent case studies in central Chile and southeastern Mexico. In Chile, we find that the 1997 intraslab event had an exceptionally large E/M0 ratio, 30 times greater than the nearby interplate shock. This suggests a very fast strain release at the source as the origin of the particularly destructive character of intraslab events. While the difference is less sharp in Mexico, we find a similar trend, which is in agreement with the observation that the locally most damaging earthquakes are indeed the intraslab events. We also document on the 1939 Chilean earthquake the feasibility of extending this approach to historical earthquakes for which high-quality analog records have been archived.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Energy-to-moment ratios for damaging intraslab earthquakes: preliminary results on a few case studies
Series title:
Open-File Report
Series number:
2002-328
Year Published:
2001
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Earthquake Science Center
Description:
pp. 117-121
Larger Work Type:
Report
Larger Work Subtype:
USGS Numbered Series
Larger Work Title:
The Cascadia Subduction Zone and related subduction systems: seismic structure, intraslab earthquakes and processes, and earthquake hazards (Open-File Report 2002-328)
First page:
117
Last page:
121
Number of Pages:
5