[U-09] Submarine volcanic eruption in Tonga accompanied by a meteo-tsunami

[U09-P26] Estimating volume of initial sea-surface height in the 2022 Tonga volcanic eruption using seafloor pressure records

*Hiroaki Tsushima¹, Yutaka Hayashi¹ (1.Meteorological Research Institute, Japan Meteorological Agency)

Keywords:2022 Tonga volcanic eruption, sea-level change, nitial sea-surface height

On January 15, 2022, at around 4:00 a.m. (UTC), the submarine volcano Hunga Tonga-Hunga Haapai erupted. Atmospheric pressure changes and sea level changes were observed around the world. There is the possibility that the atmospheric waves associated with the eruption may have excited sea-level displacement by atmospheric and oceanic resonance during their propagation process, which has been investigated (e.g., Kohno et al., this meeting; Kubota et al., 2022, EarthArXiv). In addition, since most of the volcanic island disappeared after the eruption, solid Earth phenomena such as ground deformation may have occurred and generated tsunami. Therefore, the observed sea-level changes contain not only the contribution of atmospheric pressure changes, but also tsunamis originating from solid Earth phenomena. In this study, we estimated the volume of the initial sea-surface displacement at the volcano location using the seafloor water pressure records of S-net and DONET, that is deployed off the coast of Japan, to know the magnitude of the following phenomena: (1) solid earth phenomena occurring at the volcano location on the lateral scale of the volcanic island, and (2) source of significant pressure changes in the seafloor water pressure records.

This study was partly supported by JSPS KAKENHI Grant Number JP21K21353.