Significant Elastic Ground Deformations After the January 15, 2022 Hunga-Tonga Eruption

Abstract

This study reports the unusual decimeter-scale elastic ground deformations observed by the Global Navigation Satellite System (GNSS) station TONG in Nuku’alofa after the tremendous January 15, 2022 Hunga-Tonga eruption. There are significant uplifts with a maximum of 0.35 m in the vertical direction; the elastic deformations are also obvious with a maximum of 0.15 m in the south direction while are very tiny in the east direction. In addition, the occurred period of the elastic deformations is consistent to the eruption-induced tsunamis recorded in a nearby tide gauge station. The characteristics of the observed elastic deformations confirm their link to the Hunga-Tonga eruption. The possible cause for the elastic deformations is the sustained thrusts from the eruption.