Waves Generated by Discrete and Sustained Gas Eruptions With Implications for Submarine Volcanic Tsunamis

Abstract

Impulsive subaqueous volcanic eruptions can displace a large volume of water, which has the potential to initiate local tsunamis (Day, 2015). Tsunamis triggered by underwater volcanic eruptions are relatively infrequent, accounting for approximately 1% of recorded tsunamis (Latter, 1981). Compared to tsunami generation by earthquakes or landslides, which account for 81% and 7% of recorded tsunamis respectively (Harbitz et al., 2014), the consequences of submarine volcanic sources may therefore be underestimated (Paris, 2015). Although submarine volcanic eruptions represent about three-quarters of global volcanism (most are effusive eruptions, but explosive ones also occur), these eruptions account for only 8% of the recorded eruptions because of the difficulties in obtaining observations (Cashman & Fiske, 1991;Mastin & Witter, 2000;Resing et al., 2011;White et al., 2015). No field data set completely records a submarine volcanic tsunami from the source dynamics to the water-volcanic substance interactions and finally to spatio-temporally resolved waves (Dürig et al., 2020;Embley et al., 2006;Shen et al., 2021b). Hence, laboratory experiments are required to better understand this hazard mechanism.Recent work (Shen et al., 2021b) has found that, for a given source intensity, there is a critical water depth at which a discrete eruption generates the largest wave heights. This opens two questions: (a) How does the