New Earthquake Classification for the NGA-Subduction Project
Date: 4/24/2019
Time: 06:00 PM
Room: Grand Ballroom
The NGA-Subduction project evaluated two new Class 2 (C2) aftershock classification methods. Each method uses the time window from Gardner and Knopoff (1974) and distance windows of 10, 20, 40, and 80 kilometers are evaluated. The difference between the methods is in the distance metric that is used. One method uses a distance metric for C2 earthquakes based on the closest distance from the Class 1 (C1) rupture plane to the C2 hypocenter while the other method uses the closest distance from the C1 rupture plane to the C2 rupture plane. Ultimately, the choice of the distance window width is left to the expert judgment of each developer team. Using a distance window of 40 kilometers, ground motions for the C2 aftershocks are about ten percent lower than the ground motions for C1 events over all spectral period. We present Class 1 and Class 2 results for the NGA-subduction database and provide examples of how they are applied in the subduction GMPEs.
Presenting Author: Norman Abrahamson
Authors
Kathryn E Wooddell katie.wooddell@gmail.com Pacific Gas and Electric Company, Pinole, California, United States Corresponding Author
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Norman Abrahamson abrahamson@berkeley.edu University of California, Berkeley, Berkeley, California, United States Presenting Author
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Yousef Bozorgnia yousef.bozorgnia@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Kenneth W Campbell kcampbell@corelogic.com CoreLogic, Inc., Irvine, California, United States |
Jonathan P Stewart jstewart@seas.ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Brian S J Chiou brian.chiou@dot.ca.gov California Department of Transportation, Sacramento, California, United States |
Robert R Youngs bob.youngs@amec.com John Wood Group PLC, Oakland, California, United States |
New Earthquake Classification for the NGA-Subduction Project
Category
Earthquake Ground Motions and Structural Response in Subduction Zones: A Focus on Cascadia