Volcanic Eruption Triggers a Rare Meteotsunami in the Indian Ocean

Abstract

This study presents the observation and evaluation of a meteotsunami in the Indian Ocean triggered by the Hunga-Tonga volcanic eruption. The event was detected through tide gauges and bottom-pressure recordings across the Indian Ocean, with an amplitude of 10–15 cm, lasting for a few days. A numerical model was used to understand the ocean's response to meteotsunami and evaluate the dynamics behind it. The model results show that the sea-level oscillations result from the ocean waves generated by a propagating Lamb wave. In addition to interaction with bathymetry, refracted and reflected waves also determine the sea-level variability. Our analysis shows that bathymetric slope plays a vital role in near-shore processes. The spectral and spatial characteristics of the meteotsunami were reminiscent of seismic tsunamis. Our research on this rare event elucidates the unresolved issues and eventually leads to designing a blueprint for future observation and modeling of meteotsunamis and seismic tsunamis.