SCEC Award Number 08016 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Developing Physical Limits to Ground Motion
Investigator(s)
Name Organization
Yehuda Ben-Zion University of Southern California
Other Participants Zhe-qiang Shi
SCEC Priorities B2, A7, B5 SCEC Groups GMP, SHRA, ExGM
Report Due Date 02/28/2009 Date Report Submitted N/A
Project Abstract
 Studies under this project attempt to improve the understanding of physical limits to ground motion generated by earthquakes. Our last year investigations focused on the following two research directions: (1) Understanding how generation of rock damage at the source affects the seismic radiation to the bulk. (2) Calculations of statistical properties of earthquake stress drops in models of long-term evolutionary seismicity on a heterogeneous fault. The most striking result is that reduction of elastic moduli in the source volume is shown to be capable of increasing significantly the radiation to the bulk.
Intellectual Merit The most striking theoretical result from research direction (1) is that reduction of elastic moduli in the source volume is shown to be capable of increasing significantly the radiation to the bulk. The results from research direction (2) can resolve the discrepancy between traditional estimates of stress drops and seismological observations. The general tendency for low stress drops of large events provides a rationale for reducing the statistical estimates of potential ground motion associated with large earthquakes.
Broader Impacts The results can be used to improve the estimates of maximum ground motion, and hence expected shaking hazard.
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