Richard Wysoczanski

Abstract The climactic explosive eruption of Hunga volcano in January 2022 destroyed a significant portion of the Hunga Tonga-Hunga Ha’apai islands, deepening the caldera floor by over 600 m and depositing 3.5 km3 of material onto its submarine flanks. In April–May 2022, just three months after the event, we conducted a rapid-response marine survey.

Abstract Underwater sediment density currents triggered by marine volcanic eruptions threaten island communities and infrastructure, while their deposits provide archives of past eruptions. Despite their significance, scarce real-time density current observations and concurrent deposit samples limit our understanding of their behaviour and relationship to varying volcanic mechanisms.

Abstract The impacts of large terrestrial volcanic eruptions are apparent from satellite monitoring and direct observations. However, more than three quarters of all volcanic outputs worldwide lie submerged beneath the ocean, and the risks they pose to people, infrastructure, and benthic ecosystems remain poorly understood due to inaccessibility and a lack of detailed observations before and after eruptions.