New behaviour of the Piton de La Fournaise volcano feeding system (La Réunion Island) deduced from GPS data: Influence of the 2007 Dolomieu caldera collapse

After 15 months of summit deflation, the unrest of Piton de La Fournaise renewed in August 2008 with several seismic crises and the re-pressurization of the plumbing system. The successive seismic crises, sometime accompanied by ground displacements detected by GPS, were associated with inter-eruptive dyke intrusions. It was the first time since the implementation of the observatory that such successive inter-eruptive magma migrations, not reaching the surface, were observed at Piton de La Fournaise. The change in the volcano activity, with an increase in the frequency of pure dyke intrusions, have followed the Dolomieu caldera collapse of April 2007 and reveals its strong influence on the new eruptive regime. Stress changes in the volcanic edifice have, temporarily at least, favoured the arrest of dykes in depth. During these successive dyke intrusions, magma stopped at shallow depth to form transitory magma storages before to erupt during three successive small summit eruptions (September 21st–October 2nd, 2008; November 27th; and December 14th, 2008–February 4th, 2009). The same kind of change in the pre-eruptive and eruptive behaviour can be expected on other volcanoes having experienced a summit caldera collapse.

[1]  S. Vergniolle,et al.  Pressure, gas content and eruption periodicity of a shallow, crystallising magma chamber , 1989 .

[2]  N. Villeneuve,et al.  Role of the structural inheritance of the oceanic lithosphere in the magmato-tectonic evolution of Piton de la Fournaise volcano (La Réunion Island) , 2007 .

[3]  F. Albarède.  RESIDENCE TIME ANALYSIS OF GEOCHEMICAL FLUCTUATIONS IN VOLCANIC SERIES , 1993 .

[4]  John J. Dvorak,et al.  Volcano geodesy: The search for magma reservoirs and the formation of eruptive vents , 1997 .

[5]  A. Peltier,et al.  Cyclic magma storages and transfers at Piton de La Fournaise volcano (La Réunion hotspot) inferred from deformation and geochemical data , 2008 .

[6]  M. Condomines,et al.  Magma residence time beneath the Piton de la Fournaise Volcano, Reunion Island, from U-series disequilibria , 2005 .

[7]  W. J. McGUIRE.  Monitoring active volcanoes , 1991, Journal of the Geological Society.

[8]  Valérie Cayol,et al.  3D mixed boundary elements for elastostatic deformation field analysis , 1997 .

[9]  Joan Martí,et al.  The Las Cañadas caldera (Tenerife, Canary Islands): an overlapping collapse caldera generated by magma-chamber migration , 2000 .

[10]  A. Peltier,et al.  Formation of the April 2007 caldera collapse at Piton de la Fournaise volcano: Insights from GPS data , 2009 .

[11]  Mimmo Palano,et al.  Ground deformation patterns at Mt. Etna from 1993 to 2000 from joint use of InSAR and GPS techniques , 2008 .

[12]  Agust Gudmundsson.  Toughness and failure of volcanic edifices , 2009 .

[13]  A. Peltier,et al.  Constraints on magma transfers and structures involved in the 2003 activity at Piton de La Fournaise from displacement data , 2007 .

[14]  Aline Peltier,et al.  Magma transport and storage at Piton de La Fournaise (La Réunion) between 1972 and 2007: A review of geophysical and geochemical data , 2009 .

[15]  Valérie Cayol,et al.  Finding realistic dike models from interferometric synthetic aperture radar data: The February 2000 eruption at Piton de la Fournaise , 2005 .

[16]  N. Villeneuve,et al.  How summit calderas collapse on basaltic volcanoes: New insights from the April 2007 caldera collapse of Piton de la Fournaise volcano , 2008 .

[17]  T. Staudacher.  Field observations of the 2008 summit eruption at Piton de la Fournaise (Ile de La Réunion) and implications for the 2007 Dolomieu collapse , 2010 .

[18]  James H. Dieterich,et al.  Finite element modeling of surface deformation associated with volcanism , 1975 .

[19]  Giuseppe Puglisi,et al.  Dynamics of Mount Etna Volcano inferred from static and kinematic GPS measurements , 2004 .

[20]  H. Garbeil,et al.  The 12 September 1999 Upper East Rift Zone dike intrusion at Kilauea Volcano, Hawaii , 2002 .

[21]  Agust Gudmundsson.  How local stresses control magma-chamber ruptures, dyke injections, and eruptions in composite volcanoes , 2006 .

[22]  S. Blake.  Volcanism and the dynamics of open magma chambers , 1981, Nature.

[23]  Benoit Taisne,et al.  Eruption versus intrusion? Arrest of propagation of constant volume, buoyant, liquid-filled cracks in an elastic, brittle host , 2009 .

[24]  J. Martí,et al.  April 2007 collapse of Piton de la Fournaise: A new example of caldera formation , 2007 .

[25]  A. Gudmundsson.  Surface stresses associated with arrested dykes in rift zones , 2003 .

[26]  F. Massin,et al.  The April 2007 eruption and the Dolomieu crater collapse, two major events at Piton de la Fournaise (La Réunion Island, Indian Ocean) , 2009 .

[27]  Minoru Urai,et al.  Size and volume evaluation of the caldera collapse on Piton de la Fournaise volcano during the April 2007 eruption using ASTER stereo imagery , 2007 .