Validation of Ground Motions From a Deterministic Earthquake Sequence Simulator
Date: 4/25/2019
Time: 09:15 AM
Room: Elliott Bay
The Collaboratory for Interseismic Simulation and Modeling (CISM) is investigating the efficacy of a multi-cycle deterministic earthquake simulator as an extended earthquake rupture forecast (ERF) for use in generating synthetic ground motions for probabilistic seismic hazard analysis (PSHA). While use of deterministic ground motion simulations in PSHA calculations is not new (e.g. CyberShake, Graves et al. 2011), prior studies relied on kinematic rupture generators to extend empirical ERFs. Fully-dynamic models, which simulate rupture nucleation and propagation of static and dynamic stresses, are computationally intractable for the large simulation domains and many seismic cycles required to perform PSHA. Instead, we use the Rate-State Earthquake Simulator (RSQSim), developed by Dieterich & Richards-Dinger (2010), to efficiently simulate millions of years of M>6 earthquake sequences on the California fault system. RSQSim produces full slip-time histories for each rupture, which, unlike kinematic models, emerge from frictional properties, fault geometry, and stress transfer; all intrinsic variability is deterministic. We use these slip-time histories directly as input to wave propagation codes with the SCEC BroadBand Platform (BBP) for one-dimensional models of the Earth and SCEC CyberShake for three-dimensional models to obtain simulated deterministic ground motions.
We compare median and variance of RSQSim ground motions and magnitude-scaling with recordings and models (empirical and kinematic). Validation exercises include reproduction of the SCEC BBP “Part B” criteria (Goulet et al. 2014), and comparison of the partitioned variance structure (source, site, path) of computed ground motions to that obtained from the NGA-West2 ground motion database (Ancheta et al. 2014). These validation exercises inspired a number of enhancements to the RSQSim model, and promising initial results suggest that RSQSim is a suitable source model for deterministic PSHA calculations.
Presenting Author: Kevin R. Milner
Authors
Kevin R Milner kmilner@usc.edu University of Southern California, Los Angeles, California, United States Presenting Author
Corresponding Author
|
Bruce E Shaw shaw@ldeo.columbia.edu Lamont-Doherty Earth Observatory, New York, New York, United States |
Keith B Richards-Dinger keithrd@ucr.edu University of California, Riverside, Riverside, California, United States |
Christine A Goulet cgoulet@usc.edu University of Southern California, Los Angeles, California, United States |
Scott Callaghan scottcal@usc.edu University of Southern California, Los Angeles, California, United States |
Xiaofeng Meng xiaofenm@usc.edu University of Southern California, Los Angeles, California, United States |
Jacquelyn A Gilchrist jacquig@gmail.com University of Southern California, Los Angeles, California, United States |
James H Dieterich dieterichj@ucr.edu University of California, Riverside, Riverside, California, United States |
Philip J Maechling maechlin@usc.edu University of Southern California, Los Angeles, California, United States |
Thomas H Jordan tjordan@usc.edu University of Southern California, Los Angeles, California, United States |
Validation of Ground Motions From a Deterministic Earthquake Sequence Simulator
Category
Numerical Modeling of Earthquake Ground Motion, Seismic Noise, Rupture Dynamics and Seismic Wave Propagation