SEATANI: hazards from seamounts in Southeast Asia, Taiwan, and Andaman and Nicobar Islands (eastern India)

Abstract

Submarine volcanism makes up approximately 85 % of volcanism that occurs on Earth, and its eruptions have the potential to cause several hazards including ash dispersal, pumice rafts, pyroclastic density currents, sector collapses, and tsunamis. Recent examples include the eruptions in Japan and in the Kingdom of Tonga in 2021 and 2022 respectively, but there has been little to no study of submarine volcanism in Southeast Asia and surroundings. Here we provide a compilation of 466 seamounts from the region, from different published sources, through the SEATANI dataset (Southeast Asia, Taiwan, and the Andaman and Nicobar Islands). We use this newly compiled dataset to assess on a regional level the seamount hazard potential and exposure potential as a springboard for future more quantitative hazard studies of the region. The hazard potential was assessed through seamount morphological and structural analyses, to determine the seamount evolution stage and grade of maturity. The exposure potential was evaluated with two different approaches: an areal analysis of the number of assets within a 100 km radius of each seamount and the development of a hazard-weighted seamount density map to highlight potential areas of interest for future more-in-depth studies. Our results show that there are several potentially hazardous seamounts in this region. Taiwan has the highest hazard and exposure potential, for all assets considered, while the Philippines, Indonesia, and Vietnam have relatively high exposure potential for submarine communication cables and ship traffic density. The results from this work serve as a first step towards Southeast Asia and neighbouring countries becoming more resilient against and prepared for submarine volcanic eruptions in the region.