Abstract
In the 2011 Tohoku earthquake tsunami disaster, the actual tsunami heights greatly exceeded the estimated heights and this underestimation resulted in serious damage in Japan. After the Tohoku tsunami, the Cabinet Office of Japan4),5) reported a large slip zone (LSZ) and a super large slip zone (SLSZ) related to asperity and their assumed tsunami fault models. This led to organizations considering a new assumption in fault models. However, the resulting shapes or locations of LSZ and SLSZ differed from those reported by the Cabinet Office and organizations, and a standard method has not yet been decided. Seto and Takahashi1) proposed a model for analyzing multiple tsunami scenarios that considers the uncertainties in LSZ and SLSZ. However, that model did not allow considering multiple LSZ and SLSZ, uncertainty in the hypocenter, or uncertainty in the seismic magnitude. In the present study, a general model that considers all of the above uncertainties is proposed. The proposed model is applied to the Nankai Trough to assume multiple tsunami scenarios, and the detailed procedures for using the model are clarified. As an application to tsunami disaster mitigation by using multiple tsunami scenarios, the relationship between the predominant period and the tsunami source is examined. The predominant period is an important factor for tsunami disaster mitigation because it relates to both whether a tsunami warning should be cancelled and how the tsunami height will be amplified inside a port.
