Improvement of characterized source model and displacement waveform calculation considering detailed distribution of surface rupture of Kumamoto earthquake

Abstract

In the conventional characterized source model used for strong motion prediction, it has been said that seismic motion is not generated 2 km underground from the viewpoint of stress effect, but it may underestimate the seismic motion. This study presents a new fault model that incorporates the detailed displacement distribution of surface seismic faults obtained as active fault information from tectonic landform surveys into shallow slips. The calculation results confirmed a decrease in the rate of underestimation of the horizontal component. The vertical components tended to differ depending on the joining conditions of the amount of slip on the ground surface and the amount of slip on the ground.