THREE-DIMENSIONAL TSUNAMI PROPAGATION SIMULATION OF NANKAI TROUGH GREAT EARTHQUAKE TSUNAMI

Abstract

 We conducted tsunami propagation simulations using a 3D tsunami model based on OpenFOAM and compared their accuracy with an analytical solution and results by 2D tsunami models. The results showed that the 3D tsunami model is capable to reproduce disperse waves of shorter wavelengths with higher accuracy than the conventional 2D dispersive wave tsunami model. Moreover, for the Nankai Trough giant earthquake simulation, it was suggested that the 3D tsunami model could predict the short-wavelength tsunami caused by a large slip zone near the trench axis with higher accuracy than the 2D model. The computation time required for the tsunami simulation of the Nankai Trough giant earthquake case was faster than real time with the parallel calculation using about 1,000 cores. It was confirmed that a wide-area 3D tsunami propagation simulation that covers the tsunami source region of the Nankai Trough giant earthquake can be practically imple-mented if an appropriate parallel computing environment is available, and is effective to reproduce short-wavelength component of tsunamis.