HR: 1330h
AN: V22A-0570    [PDF]
TI: 3D Modeling of the Dike Intrusions at Piton de la Fournaise Using Radar Interferometry Between 1998 and 2000
AU: Fukushima, Y
EM: yofukushima@opgc.univ-bpclermont.fr
AF: Laboratoire Magmas et Volcans, Univ. B. Pascal, CNRS UMR 6524, 5 rue Kessler, Clermont-Ferrand, 63038 France, Metropolitan
AU: Durand, P
EM: Philippe.Durand@cnes.fr
AF: Centre National d'Etudes Spatiales, 18 Avenue E. Belin, Toulouse, 31055 France, Metropolitan
AU: * Cayol, V
EM: Valerie.Cayol@opgc.univ-bpclermont.fr
AF: Laboratoire Magmas et Volcans, Univ. B. Pascal, CNRS UMR 6524, 5 rue Kessler, Clermont-Ferrand, 63038 France, Metropolitan
AB: Piton de la Fournaise volcano (R\'{e}union Island) has been experiencing frequent eruptions since March 1998 after more than five years of rest. The displacements associated to the five eruptions, from March 1998 to June 2000, have been recorded by the RADARSAT-1 satellite. A total of 18 ascending and descending interferograms were computed from the images recorded in fine mode. They show that the March 1998 and February 2000 eruptions caused asymmetric displacements with the eastern side of the eruptive fissures moving seaward by up to 50 cm and negligeable displacements west of the fissures. These eruptions occured north of the central craters. On the other hand, the September 1999 and June 2000 eruptions which occured south of the central craters showed symmetric displacement patterns. The displacements were modeled using a three-dimensional boundary element method that takes the topography into account. With this method, pressure sources (magma chambers, fractures) and shear faults of any shapes can also be taken into account. Acceptable models of the dike geometry and the pressure parameters (over pressure and pressure gradient) for the five eruptions were found using a neighbourhood algorithm (Sambridge, 1999). Preliminary results show a dike location consistent with the center of inflation determined using clinometric data.
DE: 1243 Space geodetic surveys
DE: 3210 Modeling
DE: 3260 Inverse theory
DE: 8414 Eruption mechanisms
DE: 8434 Magma migration
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting