HIGH DENSITY PREDICTIONS OF STRONG MOTION IN TSUNAMI ATTACK AREA, KUSHIMOTO TOWN, WAKAYAMA PREFECTURE, JAPAN DURING A SCENARIO EARTHQUAKE WITH M_W9.0 ALONG THE NANKAI TROUGH BASED ON THE SMGA MODELS CONSIDERING LOCAL SITE EFFECTS

Abstract

 During a scenario earthquake with M_W9.0 along the Nankai Trough, not only strong motion but also huge tsunami is predicted in Kushimoto Town, Wakayama Prefecture, Japan. In this study, first, based on the empirical relationship between microtremor H/V spectrum and site amplification factor, the site amplification factors from seismic bedrock to ground surface at the 525 sites in the tsunami attack area were evaluated. Seismic waveforms in the area were then predicted with very high density based on the SMGA models considering the empirical site amplification factors. Using the detailed distribution of several indices due to the predicted seismic waveforms, finally, we discussed the influence which the action of the strong motion has on tsunami evacuation.