The Hayward Fault presents significant seismic hazard to the eastern San Francisco Bay Area (the “East Bay”). We report on a high-performance computing (HPC) simulation of strong ground motions for a magnitude (M) 7.0 scenario earthquake on the Hayward Fault resolved to 5 Hz and higher. We computed seismic motions obeying physics-based wave propagation in a regional-scale, three-dimensional (3D) Earth model with surface topography with the SW4 finite difference code. Both plane-layered (one-dimensional, 1D) and 3D earth models were considered, with 3D sub-surface material properties and topography sub-sampled from a 3D model by the USGS. The resulting ground motion intensities (peak ground acceleration and velocity, RotD50 spectral accelerations) are in good agreement with ground motion models (GMM) based on empirical data. Median intensities for sites across the domain are within the reported uncertainties of the Abrahamson et al. (2014) GMM across spectral periods 0.2-10 seconds (frequencies 0.1-5 Hz). These results demonstrate that earthquake simulations with fully 3D deterministic wave propagation on world-class HPC platforms provides ground motions consistent with empirical models for frequencies of relevance to engineering analysis.
Arthur Rodgers Seismologist, Lawrence Livermore National Laboratory Arthur Rodgers studied Physics at Northeastern University (B.S, 1986) and the University of Colorado, Boulder (Ph.D, 1993). He worked as a post-doc at New Mexico State University (1994) and the University of California Santa Cruz (1994-1996). He joined the Seismology Group at LLNL as a postdoc in 1997 and was the Seismology Group Leader 2006-2010. In 2010 he was a Fulbright Scholar to Grenoble, France. In addition to being a permanent technical staff member at LLNL, Dr. Rodgers is a Visiting Scientist at the University of California, Berkeley Seismological Laboratory and an Affiliate of Lawrence Berkeley National Laboratory.
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