Numerical Modeling and Analysis of Waves Induced by Submerged and Aerial/Sub-aerial Landslides

Two dimensional tsunami waves induced by submerged or aerial/sub-aerial rigid slider with and without sudden stop are simulated in time domain by using fully-nonlinear NWT (numerical wave tank) technique. Special attentions are paid on the maximum free-surface depression/rise and the resultant run-up near shoreline to assess relevant potential hazard. The fully-nonlinear results are compared with linear results. The free-surface deformation and run-up increase with mass height and sliding velocity and the growth rate can be better predicted by using the nonlinear simulation. The cases with or without sudden stop are next compared. The maximum free-surface rise/fall as well as shoreline run-up significantly increases in the case of sudden stop due to additional transient waves generated by the impact-like change of motion. The aerial/sub-aerial cases are also compared with submerged/underwater cases. Through a series of parametric investigations, it is clearly seen that the potential tsunami risk of aerial/sub-aerial land slide is much higher than that of submerged underwater land slide.