SPH simulation of surge waves generated by aerial and submarine landslides

Abstract

Since the Indian Ocean Tsunami in 2004, there has been extensive research on tsunami modelling. Tsunami catastrophes were generally generated by earthquake fault plate or mass landslide. This article is focused on surge waves induced by mass landslides. Here we restrict to two dimensional study, in which a solid mass was sliding down over a sloping beach. Our approach is numerical simulation using the Smoothed Particle Hydrodynamics (SPH) method. The SPH method is a Lagrangian meshless method, commonly used to describe complex events. Here, the solid mass was modeled as a solid box with triangular-cross section. Its movement follows analytical solution derived by Watts in [1]. The SPH method was used to simulate surge waves induced by two types of landslides; aerial and submarine. Our results were validated using the experimental data of Heinrich [2]. It was shown that the resulting waves induced by aerial and submarine landslides as well as the solid box movement agree quite well with the experimental data. The Root Mean Square Error (RMSE) of free surface deformation in aerial simulation recorded at time t = 0.6, 1.0, 1.5 are 0.02053, 0.02342, 0.02221, respectively and in submarine simulation recorded at time t = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 are 0.02908, 0.04085, 0.03772, 0.03843, 0.03753, 0.02582, respectively. Whereas motion of the solid box in submarine simulation has better accuracy than in aerial simulation with RMSE 0.00799 and 0.03831, respectively.