The Great East Japan Earthquake Disaster and integrated earthquake simulation for earthquake hazard and disaster estimate

2011 Tohoku Earthquake is the largest earthquake that has been observed in Japan, and it has induced Great East Japan Earthquake Disaster together with gigantic tsunami. This tragic event is making an impact on numerical simulation researchers to develop a better tool of making more rational earthquake hazard and disaster estimate. Integrated earthquake simulation is a candidate of such a tool, since it computes all phases of the earthquake hazard and disaster, by seamlessly combining various numerical analysis methods. Two examples of this simulation, applied to Tohoku and Tokyo areas, are presented in this paper. Seamless coupling of the wave amplification analysis and the structure seismic response analysis of an urban area is presented. A core element of the integrated earthquake simulation is the wave amplification analysis for a surface ground model. A parallel finite element method is developed for this purpose, and its key features which are essential for high performance computing are explained, together with an example of simulating the wave amplification process in valley plane.