April 2007 collapse of Piton de la Fournaise: A new example of caldera formation

Laurent Michon (1) , Thomas Staudacher (2) , Valérie Ferrazzini (2) , Patrick Bachèlery (1) , Joan Marti (3)

1 LGSR - Laboratoire GéoSciences Réunion
2 OVPF - Observatoire Volcanologique du Piton de la Fournaise
3 VICOROB - Research institute of Computer Vision and Robotics [Girona]

Collapse calderas are frequent in the evolution of volcanic systems, but very few have formed during historical times. Piton de la Fournaise is one of the world's most active basaltic shield volcanoes. The caldera collapse, which occurred during the April 2007 lateral eruption is one of the few large documented collapse events on this volcano. It helps to understand the mode and origin of caldera collapses in basaltic volcanoes. Field observations, GPS and seismic data show that the collapse occurred at an early stage of the eruption. The cyclic seismic signal suggests a step by step collapse that directly influenced the lateral eruption rate. Likely, the caldera results from the combined effect of (i) the progressive collapse of the plumbing system above the magma chamber since 2000, and (ii) the large amount of magma withdrawal during the early stage of the eruption by both a significant intrusion within the edifice and an important emission rate.

Domains: Sciences of the Universe [physics]

Laurent Michon, Thomas Staudacher, Valérie Ferrazzini, Patrick Bachèlery, Joan Marti. April 2007 collapse of Piton de la Fournaise: A new example of caldera formation. Geophysical Research Letters, 2007, ⟨10.1029/2007GL031248⟩. ⟨insu-01285148⟩