Where does a volcano break? Using self-potential reiteration to forecast the precise location of major destructive events on active volcanoes: the case study of the Piton de la Fournaise 2007 caldera collapse
1LGSR - Laboratoire GéoSciences Réunion (Faculté des Sciences et techniques - Université de La Réunion 15 avenue René Cassin CS92003 97744 SAINT DENIS CEDEX 9 - Réunion)
Abstract : In April 2007, the Dolomieu caldera collapse was one of the most outstanding events of the last few decades at Piton de la Fournaise volcano. Forecasting the occurrence of such a destructive event is difficult but since then, the development of tools and monitoring networks has improved our knowledge of the dynamics of volcano instability. However, the precise location of volcano failure is still hard to constrain. In this paper, we show that reiteration of self-potential (SP) measurements taken at a one meter step-size along a 440-m-long profile prior to caldera collapse brings valuable insights on the most instable areas around the Dolomieu crater. SP signal dynamic reveals information not visible on one single SP acquisition. In particular, the SP dynamic highlights the presence of low cohesion/low strength materials at depth despite a lack of surface expression. Our survey at Piton de la Four-naise showed that preferential failure area can be precisely identified, at the meter scale. These results highlight the relevance of SP reiteration measurements as a tool for locating instabilities in both volcanic and non-volcanic environments.
https://hal.univ-reunion.fr/hal-02300853
Contributor : Laurent Michon
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Submitted on : Monday, September 30, 2019 - 4:39:30 AM
Last modification on : Wednesday, October 9, 2019 - 2:51:22 PM
Long-term archiving on: Monday, February 10, 2020 - 8:00:24 AM
Marie Chaput, Anthony Finizola, Aline Peltier, Nicolas Villeneuve, Marie Crovisier, et al.. Where does a volcano break? Using self-potential reiteration to forecast the precise location of major destructive events on active volcanoes: the case study of the Piton de la Fournaise 2007 caldera collapse. Volcanica, Presses Universitaires de Strasbourg, 2019, 2 (2), ⟨10.30909/vol.02.02.151159⟩. ⟨hal-02300853⟩
