Eruption of Soufrière Hills (1995–2009) from an offshore perspective: Insights from repeated swath bathymetry surveys

A Le Friant (1) , C Deplus (1) , G Boudon (1) , N Feuillet (1) , J Trofimovs (2) , J ‐c Komorowski (1) , S S J Sparks (3) , P Talling (4) , S Loughlin (5) , M Palmer (4) , G Ryan (6)

1 IPGP - Institut de Physique du Globe de Paris
2 NOC - National Oceanography Centre [Southampton]
3 School of Earth Sciences [Bristol]
4 National Oceanography Center
5 British Geological Survey [Edinburgh]
6 Institute of Earth Science and Engineering

This contribution provides an analysis of the 1995–2009 eruptive period of Soufrière Hills volcano (Montserrat) from a unique offshore perspective. The methodology is based on five repeated swath bathymetric surveys. The difference between the 2009 and 1999 bathymetry suggests that at least 395 Mm3 of material has entered the sea. This proximal deposit reaches 95 m thick and extends ∼7km from shore. However, the difference map does not include either the finer distal part of the submarine deposit or the submarine part of the delta close to the shoreline. We took both contributions into account by using additional information such as that from marine sediment cores. By March 2009, at least 65% of the material erupted throughout the eruption has been deposited into the sea. This work provides an excellent basis for assessing the future activity of the Soufrière Hills volcano (including potential collapse), and other volcanoes on small islands.

Domaines: Volcanologie

A Le Friant, C Deplus, G Boudon, N Feuillet, J Trofimovs, et al.. Eruption of Soufrière Hills (1995–2009) from an offshore perspective: Insights from repeated swath bathymetry surveys. Geophysical Research Letters, 2010, 37 (19), pp.L11307. ⟨10.1029/2010GL043580⟩. ⟨insu-01586256⟩