PHYSICAL PROCESSES IN SUBMARINE SILICIC ERUPTIONS (Invited Presentation)

Eruptions in submarine environments have rarely been observed and are not commonly detected despite comprising the majority of the volcanic output on our planet. As a result, much of what we learn about submarine volcanic processes requires interpretation of deposits that, if we are fortunate, can be combined with some real-time observations. Two recent submarine silicic eruptions have provided such opportunities: Havre Volcano (2012) in the Kermadec Arc and Hunga-Tonga Volcano (2022) in the Kingdom of Tonga. These two eruptions offer a compelling contrast in eruption styles, effusive and explosive respectively, dictated in large part by their eruption depths below sea level. However, both eruptions created significant disturbances to the benthos, water column, and sea-surface, the extent of which has not been fully quantified. This presentation will summarize field observations from both eruptions and highlight some of the outstanding critical questions that remain about submarine silicic eruptions, the physical processes that influence their behavior, and the potential impact on local- to regional-scale oceanographic processes.