The Southern California Earthquake Center (SCEC) is using Blue Waters to develop an empirically-calibrated physics-based earthquake forecast, and to characterize the influence of source models and non-linear material response to strong shaking on the accuracy of ground motion simulations. We summarize recent progress achieved through these simulations. During the last year, we used the physics-based earthquake cycle simulator code, called RSQSim, to produce several million-year earthquake catalogs to investigate how fault complexities affect the probabilities of large, multi-fault ruptures and multi-event sequences. We also performed systematic verification of the methods and procedures currently used in three-dimensional high-frequency (f ≤ 5 Hz) earthquake ground motion simulations, using alternative numerical methods and codes. This research is improving the physical representations of earthquake processes and the deterministic codes for simulating earthquakes, which will improve probabilistic seismic hazard analysis in the United States and benefit earthquake system science worldwide.
