Tsunami Simulation Using Vertical Displacement Calculated from Simulation of Ground Motion due to Seismic Source Model

Abstract

We try to carry out the tsunami simulation using the displacement field of oceanic crustal movements, which is calculated from the ground motion simulation of the 2011 off the Pacific coast of Tohoku Earthquake. First, the large-scale ground motion simulation based on the voxel type finite element method is performed for the whole eastern Japan. The fault model based on the teleseismic body wave is assigned to the source region. Next, the tsunami simulation is performed by the finite difference calculation based on the shallow water theory. The initial wave height for tsunami generation is estimated from the vertical displacement of ocean bottom due to the crustal movements, which is obtained from the ground motion simulation mentioned above. Although the results of tsunami simulation show that synthetic waveforms are fairly consistent with the observations of the GPS wave gauges, the comparisons of synthetics and observation show that the tsunami simulation in this study underestimates the maximum wave height in most observing stations.