Volcano Growth and Destruction: Sector collapse hazards and impacts on volcano development

Dr Sebastian Watt, University of Birmingham. Part of the IGT Seminar.

Sector collapses are among the largest-volume volcanic processes, dramatically modifying the morphology of volcanoes and generating a variety of associated hazards. The potentially devastating impacts of such events are clear from the recent collapse of Anak Krakatau, in December 2018. There are relatively few historical examples of such events, and many aspects of sector collapses, from their triggers and precursory signals, through to their consequences for the magma plumbing system, remain poorly understood. In this seminar, I’ll use a variety of historical examples and older collapses to first explore the hazards associated with sector collapse and our current understanding of failure and emplacement processes, particularly on island volcanoes – and including initial results on the Anak Krakatau event. I’ll go on to consider the impacts that collapse-driven unloading may have on underlying magma reservoirs, examining evidence that suggests collapses modulate subsequent eruptive behaviour and regrowth of a volcano.