Parametrizing Physics-Based Earthquake Simulations
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Utilizing earthquake source parameter scaling relations, we formulate an extensible slip weakening friction law for quasi-static earthquake simulations. This algorithm is based on the method used to generate fault strengths for a recent earthquake simulator comparison study of the California fault system. Here we focus on the application of this algorithm in the Virtual Quake earthquake simulator. As a case study we probe the effects of the friction law’s parameters on simulated earthquake rates for the UCERF3 California fault model, and present the resulting conditional probabilities for California earthquake scenarios. The new friction model significantly extends the moment magnitude range over which simulated earthquake rates match observed rates in California, as well as substantially improving the agreement between simulated and observed scaling relations for mean slip and total rupture area.
KeywordsVirtual Quake Virtual California earthquake simulations
We would like to thank Prof. Steven N. Ward for his initial version of this stress drop algorithm, and for his advice guiding the development of this study. This research was supported by National Aeronautics and Space Administration (NASA) Earth and Space Science fellowship number NNX11AL92H. Virtual Quake is hosted by the NSF-supported Computational Infrastructure for Geodynamics (CIG). Virtual Quake is open source scientific software, is available for download and comes with a user manual (Schultz et al. 2016). URL:http://geodynamics.org/cig/software/vq/.
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