南海トラフ巨大地震を想定した西条市の揺れやすさに関する一研究

抄録

In the plain where the central part of Saijo city in Ehime Prefecture is located, differences in the seismic intensity distribution of two damage estimations by Cabinet Office and Ehime Prefecture, were observed for the Nankai Trough gigantic earthquake. To clarify the cause of the differences, microtremor observation across the plain was carried out and the validity of the soil amplification evaluation was examined. In addition, the Median Tectonic Line active fault zone crosses this plain, and we also grasped the influence of that active fault zone on ground amplification. As a result, it was explained that the difference in the two seismic intensity distributions depends on the difference in the predominant periods due to the geomorphology. Additionally, the effect of active fault was not observed.