Alteration-induced volcano instability at La Soufrière de Guadeloupe (Eastern Caribbean)

Natural Hazard Coffee // Michael Heap (University of Strasbourg) Alteration-induced volcano instability at La Soufrière de Guadeloupe (Eastern Caribbean) 29 oct. 2021 02:00 PM Paris Zoom @ https://us02web.zoom.us/j/85720657452?pwd=eGJwcDVsenozL3FVK3BNN3pxbktKZz09 ID: 857 2065 7452 Code: 590724 Abstract: The stability of a volcanic edifice is an important consideration in volcanic hazard and risk assessments due to the potentially dire consequences of partial volcanic flank collapse. Hydrothermal alteration, promoted by the interaction between hydrothermal fluids and dome- or edifice-forming rock, is common at many volcanoes and is thought to be bad news for volcano stability. However, flank stability models informed by laboratory data are extremely rare. So, does alteration result in volcano stability? Using La Soufrière de Guadeloupe (Eastern Caribbean) as a test-bed, we combined laboratory measurements, field geophysical measurements, and numerical modelling in an attempt to better understand the influence of hydrothermal alteration on the stability of a volcanic flank. Come to the seminar to find out what we found! Spoiler alert: our modelling shows that hydrothermal alteration decreases volcano stability and thus expedites volcano spreading and increases the likelihood of mass wasting events and associated volcanic hazards. We conclude that hydrothermal alteration, and its evolution, should therefore be monitored at active volcanoes worldwide. Bio: Mike Heap has been an associate professor at the University of Strasbourg since 2010. He did his undergraduate studies at University of Liverpool (UK) and his Ph.D at University College London (UK). Before his appointment at Strasbourg, he was a post-doc at Ludwig Maximilian University in Munich for just over one year (Germany). Mike's principal area of study is the physical and mechanical properties of porous rocks, and in particular porous volcanic rocks, and factors (such as porosity, deformation, pressure, and hydrothermal alteration) that can influence these properties. He has published more than 150 papers, accrued almost 6500 citations, has a h-index of 46, and has published with almost 250 different co-authors.