Numerical simulation of the Mw 6.6 2007 Niigata, Japan, earthquake: Reliable input ground motion for engineering purpose

摘要

The 2007 Niigata, Japan, earthquake. (Mw6.6) caused some damages in the Niigata Prefecture, especially around Kashiwazaki. We carry out numerical simulations of seismic wave propagation to understand the strong ground motion which has affected the Kashiwazaki area. We adopt a finite difference method with a 4~(th) order in space staggered grid. We use a 3D geological structure model, obtained by seismic tomography of aftershocks observations. Preliminary tests of this structure model confirm a good agreement of waveforms comparing to the recorded data set. We then test two finite source models, obtained by seismic kinematic inversion for the mainshock. The simulated synthetic seismograms around the Kashiwazaki area seem to be still, small in amplitude with respect to the recorded data, although the data should be influenced strongly by the non-linear soil behaviour. The geological and seismological models should be refined further and additional non-linear soil analysis should be carried out.