Numerical Modelling of Tsunami Waves from Tonga Volcano on January 15, 2022

The paper considers a catastrophic event - the eruption of Hunga Tonga-Hunga Ha'apai volcano on January 15, 2022. The process of preparation and eruption of Hunga Tonga volcano generated tsunami waves that were observed throughout the World Ocean. This event was notable for its unprecedented global impact and the early appearance of tsunami waves at distant coastal stations. So, the first waves at tide gauge stations in Chile and Peru were recorded 4 hours earlier than the arrival time of tsunami waves to the tide gauge after the eruption of Tonga volcano. Two mechanisms are possible for the generation of early tsunami waves: acoustic Lamb waves generated by a volcanic explosion and submarine landslides that occurred on the slopes of the volcano during the preparatory phase of the eruption. In this study, numerical simulation of various pre-eruption landslide scenarios on the slope of Hunga Tonga volcano is carried out in an attempt to explain these early tsunami waves. Under computation the elastoplastic model of landslide was taken into account. Wave characteristics of a tsunami on the coast of Chile and Peru generated by a landslide process on a volcanic slope are obtained. A detailed comparison of virtual tide gauge data with observational ones is used to validate this model. The results obtained can be used to improve early warning systems.