SCEC Award Number 08108 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Do earthquakes that cause exceptional peak accelerations and peak velocities have high stress parameter?
Investigator(s)
Name Organization
John G. Anderson University of Nevada, Reno James Dewey United States Geological Survey David Boore United States Geological Survey
Other Participants
SCEC Priorities B2 SCEC Groups GMP, EEII
Report Due Date 02/28/2009 Date Report Submitted N/A
Project Abstract
 Anderson (2010) developed a list of 246 earthquakes identified by the criteria that peak acceleration exceeded 500 cm/s^{2} or peak velocity exceeded 50 cm/s on at least one component. Accelerograms which met this threshold were termed “exceptional” in the sense meaning “uncommon” or “rare”. Dewey and Boore (SCEC poster) showed results of a global stress parameter they had calculated. The question addressed in this proposal was whether earthquakes in the Anderson (2010) database tend to have a higher stress parameter than average. This study found that the stress parameters of events that cause exceptional ground motions are about 30% higher than the average stress parameters of other events in the region. A possible implication is that teleseismic recordings of earthquakes that have a high stress parameter may be correlated with higher ground motions in the vicinity of the epicenter.
Intellectual Merit Correlations of levels of teleseismic and local ground motions have been elusive. The statistics of this correlation are not entirely robust, but the results do suggest that teleseisms that are rich in high frequencies, as evidenced by high values of mb, may tend to have higher levels of local ground motions.
Broader Impacts A possible implication is that teleseismic recordings of earthquakes that have a high stress parameter may be correlated with higher ground motions in the vicinity of the epicenter. This could be used together with other tools to help refine estimates of the extend of damage associated with an earthquake recorded teleseismically.
Exemplary Figure Figure 2. Residual stress parameters of the 59 matching events. (credit: John Anderson)