UNCERTAINTY ASSESSMENT OF TSUNAMI HEIGHT FOR FUTURE NANKAI-TONANKAI EARTHQUAKES USING STOCHASTIC TSUNAMI SOURCE MODELS

Abstract

 This study conducts numerical tsunami simulations for future Nankai-Tonankai earthquakes and compares the tsunami amplitudes of different earthquake source catalogs along the coastal area of Japan. One of the catalogs is 11 source models proposed by the Central Disaster Management Council (CDMC), the Cabinet Office of Japan. The other is 300 source models of the stochastic tsunami model, which allows for generating source models randomly. Along the Kochi coast, faced to the open ocean, the mean tsunami heights of the stochastic tsunami model are higher than those of the CDMC models. On the contrary, this tendency is inverted at the coast of Osaka Bay. The difference in the tsunami heights can be explained by the mean slip of the dominant fault region. This result indicates that the acceptable depth variability of the large slip in the earthquake fault model can be a major source of uncertainty in the tsunami height.