SEGJ Technical Conference

Finite Difference Method using In-equally Spaced Grids for Realistic Structures -Application to Simulation of Tsunami Propagation accommodating Seafloor Topography-

Abstract For tsunami disaster mitigation, it is important to consider the reflected and scattered waves generated by the real changes of water depth on tsunami simulation. These waves arrive at the coasts as the later phases of tsunami, sometimes the phases of the maximum height could arrive after the first arrivals. Therefore, the effects of the seafloor topography should be considered on tsunami propagating simulation. It is, however, difficult to simulate the later phases by the conventional method. In our study, we simulate a tsunami that propagates over varying seafloor topography near Japan, using FDM with three dimensional in-equally spaced grids. We find that our results show some features caused by the real changes of water depth and the amplitude is larger than that simulated by the conventional method, especially in later phases. We think that the accommodation of the real seafloor topography is indispensable for practical tsunami simulation including later phases, which would be effective for tsunami disaster mitigation.