Numerical Simulation of Submarine Landslide-Induced Tsunami Using Two-Layer Extended Boussinesq Equations

Submarine landslide-induced tsunami, which is caused by earthquakes or volcano eruptions, seriously affects humans’ lives and properties. To date, this is a challenging topic for numerical hydrodynamic researchers due to the unpredictable submarine landslide sources. Several researchers assumed the submarine landslide source as the impermeable soil layer and its movement as an elliptic shape. In this paper, the underwater soil surface is porous, water can pass through and then the submarine landslide source becomes a permeable soil layer. The submarine landslide is simulated correctly using the nonlinear shallow water equations (NSWE) and the hybrid finite volume/finite difference (FV/FD) method. To generate tsunami, the time-varying water depths and the porosity inside the submarine landslide are included as the source terms in the two-layer extended Boussinesq equations to generate waves. A high-order FD method is applied to discretize the two-layer Boussinesq equations in time and space. The numerical simulations of submarine landslide-induced tsunami for two-layer case are investigated in a specific porosity. The two-layer and one-layer results are compared and explained by real dynamical phenomena.