Publication
Pyroclastic density currents explain far-reaching and diverse seafloor impacts of the 2022 Hunga Tonga Hunga Ha’apai eruption
Publisher:
Research Square Platform LLC
Date:
17-01-2023
DOI:
10.21203/RS.3.RS-2395332/V1
Abstract: The impacts of large terrestrial volcanic eruptions are apparent from satellite monitoring and direct observations 1,2 . However, more than three quarters of all volcanoes worldwide lie submerged beneath the ocean and the risks they pose to people and infrastructure remain poorly understood due to inaccessibility and a lack of detailed observations before and after eruptions 3 . Here, comparing data acquired in 2015-2017 4,5 and three months after the January 2022 eruption of Hunga Tonga Hunga Ha’apai, we document the wide-reaching and erse impacts of the largest seaborne volcanic eruption in nearly 150 years 6 . Almost 10 km 3 of seafloor material was removed during the eruption, most of which was redeposited within 20 km of the caldera by long run-out pyroclastic currents. These powerful currents damaged seafloor cables over a length of km, reshaped the seafloor, and caused mass-mortality of seafloor life. Biological seafloor communities that survived the eruption were only observed where local topography provided a physical barrier to pyroclastic currents (e.g., on nearby seamounts). While the longer-term consequences of such a large eruption for human, ecological and climatic systems are emerging, we expect that these previously-undocumented refugia will play a key role in longer-term ecosystem recovery 7–9 .