S1.21: Volcanogenic tsunamis: generation mechanisms and hazard assessment
In active volcanic areas tsunamis are generated by a variety of mechanisms related to the type of the volcano and the mode of activity, and have been responsible for a substantial proportion of volcanic fatalities in the historical record. Usually such tsunamis are local or regional, but can still be powerful and destructive, and may in some cases be transoceanic (e.g. the 1883 Krakatau tsunami in the Indonesian arc). The 2018 sector-collapse generated tsunami at Anak Krakatau highlighted the potentially devastating impacts of volcanogenic tsunamis, as well as the current challenges in forecasting the timing of such events. Not all volcanic tsunamis are directly associated with or driven by eruptive activity. However, the relatively small number of well-observed events, as well as the diverse and complex tsunami sources, means that many aspects of this hazard remain poorly understood, limiting our ability to effectively mitigate this hazard. This session invites contributions researching all aspects of volcanic tsunamis, including volcanological interpretations of individual events and their precursors, investigations of tsunami source processes, the use of tsunami modelling in developing mitigation strategies, and approaches to monitoring and communication. Contributions about the December 2018 Anak Krakatau tsunami are particularly welcomed. Of special interest is also the development of instrumental monitoring and warning of volcanic tsunamis particularly in the near-field domain. In addition to talks and posters, we would like this session to include a discussion aimed at identifying the specific conditions that make volcanogenic tsunamis a challenging hazard to monitor and mitigate, and the approaches required to address this challenge.