Modeling a possible holocenic landslide-induced tsunami at stromboli Volcano, Italy

Abstract

Stromboli is a volcanic island in the Aeolian archipelago, located in SE Tyrrhenian sea, Italy. It is characterised by a steep depression along the NW flank of the volcano called Sciara del Fuoco, that is interpreted as the partially filled scar of a large flank collapse that took place circa 5000 years ago. The large volume of material estimated to be involved in the collapse was very likely responsible for the generation of big ocean waves. This paper presents some numerical simulations concerning a tsunami scenario to the Holocene event. For the landslide we used a Lagrangian model based on the discratization of the total sliding mass in blocks of constant volume subjected to external and internal forces. Three possible slide evolutions are considered, differing by the modality of the block-block interaction. In all three cases the tsunami is simulated using a finite-element (FE) model based on the non-linear hydrodynamic equations with the addition of a forcing term to account for the excitation of sea waves by the landslide. Wave propagation and time histories all around the island are computed. The tsunami results to be very etc. Though most of the energy is radiated seaward, nonetheless very huge waves, in the order of tens of meters, attack the island, this result being almost independent from the landslide model used.