Parallel simulation of strong ground motions during recent and historical damaging earthquakes in Tokyo, Japan

The development of high-performance computing facilities such as the Earth Simulator supercomputer and the deployment of dense networks of strong ground motion instruments in Japan (K-NET and KiK-net) have made it possible to directly visualize regional seismic wave propagation during large earthquakes. Our group has developed an efficient parallel finite difference method (FDM) code for modeling the seismic wavefield and three-dimensional visualization techniques, both of which are suitable for implementation on the Earth Simulator. We will show examples of current state of the large-scale FDM simulations of seismic wave propagation by using the Earth Simulator to recast strong ground motions during damaging earthquakes in Tokyo such as the 2000 Tottori-ken Seibu (MJ7.3) earthquake, the 1923 great Kanto earthquake (M7.9), and the 1855 Ansei Edo (M7) earthquake. Significant speed-up is achieved using 64-1406 processors of the Earth Simulator with good vector performance of over 40-60% of the theoretical peak speed.