Influence of Lithostatic Stress on Earthquake Stress Drops in North America

Earthquake stress drop is a critical parameter for estimating seismic hazard. This parameter can have a strong effect on ground motion amplitudes above ~1Hz and is especially important in Oklahoma and Kansas where earthquake rates have increased sharply since 2008. We estimate stress drops for 1121 earthquakes greater than ~M3 in and near the conterminous United States using spectral ratios between collocated events at given stations. We find that the average stress drop for the few eastern United States (EUS, 26–340 Bars) tectonic main shocks studied, which tend to be deeper thrusting events with few foreshocks and aftershocks, is about three times greater than tectonic main shocks in the western United States...

Categories: Data; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Brune stress drop, Earthquake Hazards Program, GHSC, Geologic Hazards Science Center, Geophysics, All tags... Kansas, Mohr-Coulomb theory, North America, Oklahoma, Seismology, USGS, USGS Science Data Catalog (SDC), United States, earthquake, earthquake hazard, earthquake stress drop, geophysics, ground motion amplitude, high frequency shaking hazard, lithostatic stress, seismic hazard, seismology, shear failure stress, tectonic, Fewer tags