ENERGY TRANSFER MECHANISMS OF TSUNAMIS GENERATED BY SUBAERIAL LANDSLIDES: A NUMERICAL STUDY IN OPENFOAM®

Landslide-generated tsunamis are a relevant source of hazard for lakes and coastal areas. As well known, landslide tsunamis are generally characterized by smaller length and time scales than those of tsunamis generated by earthquakes and, when a landslide occurs directly at the water body boundaries, the effects of the impulsive waves (e.g., runup, inundation, edge waves, radiated waves, Bellotti and Romano, 2017) can be magnified by the local features of the coastline and/or the bathymetry, especially for confined geometries (e.g., bays, reservoirs, lakes, and fjords). Due to the complex physical phenomena involved in the tsunami generation, near-field and far-field wave propagation and interaction with the coast, landslide tsunamis are investigated by means of physical, numerical and analytical modelling. In this paper we present a numerical study of the energy transfer mechanisms related to tsunamis generated by subaerial granular landslides. The study is carried out by using the opensource numerical framework OpenFOAM®, in which the granular material (i.e., the landslide) is modelled by using a Coulomb viscoplastic non-Newtonian rheological model, implemented in the standard solver multiPhaseInterFoam, described in the recent work of Romano et al., (2023).