HR: 1340h
AN: S43B-1069    [Abstracts]
TI: Southern California Earthquake Forecast Based on the Geodetic Strain Rate
AU: * Shen, Z
EM: zshen@ess.ucla.edu
AF: Dept of Earth and Space Sciences/UCLA, 3806 Geology, 595 Charles Young Drive, Los Angeles, CA 90095-1567 United States
AU: Jackson, D D
EM: djackson@ucla.edu
AF: Dept of Earth and Space Sciences/UCLA, 3806 Geology, 595 Charles Young Drive, Los Angeles, CA 90095-1567 United States
AB: We construct an earthquake likelihood model based on the hypothesis that earthquake frequency and magnitude distribution are related to geodetic strain rate in two ways: a) seismicity rate is steady and proportional to the average horizontal maximum shear strain rate during interseismic time period between large earthquakes; and b) earthquake magnitude distribution is spatially invariant except for an amplitude constant which is proportional to the maximum horizontal shear strain rate. We use geodetically determined maximum shear strain rate averaged from 1993-2001 to "forecast" the earthquakes, and compare strain rate with the earthquake occurrence rate. In a preliminary test, there were few earthquakes within the top 10% of the area with highest strain rate, but most of the earthquakes did occur in the next 15% of the region with highest strain rate. About 75% of the earthquakes occurred at ~25% area with highest strain rate. Therefore our preliminary test of the method yields a cautiously promising result.
DE: 1209 Tectonic deformation (6924)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
SC: Seismology [S]
MN: Fall Meeting 2005