Internal tsunami waves in a stratified ocean induced by explosive volcano eruption: A parametric source

Abstract

This article discusses the problem of generating internal waves during explosive eruptions of underwater volcanoes. The importance and novelty of such studies are associated with the emerging data on the observation of internal waves during a volcanic eruption in the Tonga Archipelago in 2022 reported in Zhang and Li [“Oceanic internal waves generated by the Tongan volcano eruption,” Acta Oceanol. Sin. 41(8), 1–4 (2022)]. Using Le Méhaute's parametric model originally suggested to calculate surface waves, internal waves in the ocean with a constant buoyancy frequency are calculated. Internal waves are trains of different modes, the parameters of which were found for different ratios between the radius of the equivalent source and the depth of the basin. Even at relatively small distances from the source (tens of km), wave amplitudes changeover time periods consisting of several days, which confirms the possibility of delineating the tsunami source by internal waves.