APPLICABILITY OF HYBRID 2D AND 3D CALCULATION FOR TSUNAMI CAUSED BY SUBMARINE VOLCANIC ERUPTION

The eruption of Hunga-Tonga Hunga-Ha‘apai on January 15, 2022, caused extensive damage to the surrounding islands. Sudden atmospheric pressure changes accompanied by the eruption caused no small sea-level fluctuations around the world. On the other hand, the tsunami that hit the islands around the submarine volcanoes is mostly caused by the sea-level change due to the eruption. One paper claimed that the maximum sea- level rise during the eruption was about 90 m, which could explain the tsunami of more than 10 m that hit Tonga (Heidarzadeh et al., 2022). This is a description of the magnitude of the explosion, but the mechanism has not yet been elucidated. Research has also suggested that tsunamis are generated by the rise of the water surface due to eruptive currents and gases during eruptions. The purpose of this study is to verify the relationship between the eruption scale and the depth of inundation around Tonga, by reproducing the eruption ejecta in three- dimensional calculations.