Numerical Simulations of Tsunami Wave Generation by Submarine Landslides: Validation and Sensitivity Analysis to Landslide Parameters

Abstract

Submarine landslide-generated waves have been responsible for significant damage to coastal communities worldwide. Despite this, the existing knowledge on the mechanism of the phenomenon is limited that can be partly attributed to the absence of adequate validated numerical models. In this study, we applied and validated a Computational Fluid Dynamics numerical model (FLOW3D-Hydro) and used it for investigating the sensitivity of landslide-generated waves to the variations of different parameters. This study is limited to solid-block submarine landslides moving downward at a fixed slope angle of 45°. We conducted 177 simulations applying the validated model by using three different sliding block sizes (small, medium, and large). The experiments revealed an inverse exponential relationship between maximum initial landslide amplitude and both initial submergence depth and travel distance. We observed that the dominant wave period generated by the large block was 0.7 s whereas it was 1.1 s for the small block; this unexpected result could be attributed to the relatively lower velocity of the sliding mass for the case of the smaller block.