Inversion of coeval shear and normal stress of Piton de la Fournaise flank displacement
| Autor: | Aurélien Augier, Jean-Luc Froger, Valérie Cayol, Marine Tridon, Patrick Bachèlery |
|---|---|
| Přispěvatelé: | Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
geography
Flank geography.geographical_feature_category 010504 meteorology & atmospheric sciences Slip (materials science) 010502 geochemistry & geophysics 01 natural sciences Detachment fault Geophysics Volcano Shear (geology) Sill 13. Climate action Space and Planetary Science Geochemistry and Petrology Interferometric synthetic aperture radar Earth and Planetary Sciences (miscellaneous) Shear stress [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology Geology Seismology 0105 earth and related environmental sciences |
| Zdroj: | Journal of Geophysical Research : Solid Earth Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2016, 121 (11), pp.7846-7866. ⟨10.1002/2016JB013330⟩ Journal of Geophysical Research : Solid Earth, 2016, 121 (11), pp.7846-7866. ⟨10.1002/2016JB013330⟩ |
| ISSN: | 2169-9313 2169-9356 |
| Popis: | International audience; The April 2007 eruption of Piton de la Fournaise was the biggest volcano eruptive crisis of the 20th and 21st centuries. Interferometric synthetic aperture radar (InSAR) captured a large coeruptive seaward displacement on the volcano's eastern flank, which continued for more than a year at a decreasing rate. Coeruptive uplift and posteruptive subsidence were also observed. While it is generally agreed that flank displacement is induced by fault slip, we suggest that this flank displacement might have been induced by a sheared sill, based on observations of sheared sills at Piton des Neiges. To test this hypothesis, we develop a new method to invert a quadrangular curved source submitted to simultaneous pressure and shear stress changes. This method, based on boundary elements, is applied to data acquired along six Envisat orbits covering a 14 month period subsequent to the April 2007 eruption. Posteruptive displacement is well explained by closure and slip of a large (5 km by 8 km) and shallow (500 m) trapezoidal fracture parallel to the flank and probably coincident with a lithological discontinuity. We investigate whether thermal contraction or degassing of a coeruptive sill can explain the displacement. Such a sill would have to be 10 times thicker than inferred from the coeruptive uplift and solidification time 10 times shorter (~20 days) than the duration of the posteruptive subsidence (24 to 33 months). Instead, we propose that the posteruptive eastern flank displacement is due to the compaction and ongoing slow slip on a shallow detachment fault. |
| Databáze: | OpenAIRE |
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