Tsunami Waves Generated by Cliff Collapse: Comparison Between Experiments and Triphasic Simulations
Résumé
Although many tsunamis arise from underwater earthquakes, some are induced by submarine and subaerial landslides. For example, the collapse of an unstable cliff into the sea can generate a tsunami wave near the coast and exhibit extreme run-up. As a result, those tsunamis develop significant hazards to the population. The threat caused by such tsunamis strongly depends on the topography and location of the unstable cliff. Predicting the height of the tsunami wave generated by a subaerial or submarine collapse requires experimental investigations, analytical modeling and numerical simulations. In this chapter, we discuss recent experimental results on granular collapse in water and the influence of the physical parameters on the amplitude of the tsunami waves. We also present triphasic numerical simulations based on a finite-volumes method, where different rheologies are considered for the slide. We also emphasize the difficulty of such simulations and compare the numerical results to experimental measurements.