← Back to Sessions

Maximum Shaking Earthquake Catalog: A Ground-Motion Based Procedure to Select Earthquakes That Are Relevant to the Seismic Hazard

Session: Probabilistic Seismic Hazard Assessment: Where Do We Go from Here? II

Type: Oral

Date: 4/20/2021

Presentation Time: 02:30 PM Pacific

Description: 

A method is proposed to identify within seismic catalogs those earthquakes that are most relevant to the seismic hazard. The approach contrasts with the classical approach to decluster the seismic catalog with the expectation that the remaining main shocks will be the relevant events for the seismic hazard analysis. We apply a time window as in the declustering approach of Gardner and Knopoff, but the time window is motivated by relevance to engineering. A ground motion criterion replaces the spatial window. An event in the time window is included in the “Maximum Shaking Earthquake Catalog (MSEQ catalog)” if the median ground motion at its epicenter exceeds the predicted median ground motion there from the main shock, using a locally appropriate ground motion prediction equation (GMPE). Ground motion can be measured by any parameter that is estimated by a GMPE. We consider peak acceleration and SA at periods of 0.2 s, 1.0 s, and 3.0 s. The longer period parameters systematically remove more small events. The purpose is not to produce a declustered catalog, in which each group of physically related earthquakes is represented by its largest event. Nonetheless, statistical properties of the MSEQ catalog somewhat resemble the corresponding declustered catalog in three tested regions. The MSEQ catalogs all retain more large-magnitude earthquakes. Thus the MSEQ catalog might be considered as an alternative to a declustered catalog, or be used to develop a list of earthquakes that are constrained to be included in a declustered catalog that is used for probabilistic seismic hazard analysis.

Presenting Author: John G. Anderson

Student Presenter: No

Authors