Seismic evidence of nonlinear crustal deformation during a large slow slip event in Mexico
Por:
Rivet D., Campillo M., Shapiro N.M., Cruz-Atienza V., Radiguet M., Cotte N., Kostoglodov V.
Publicada:
28 abr 2011
Resumen:
Repeated cross-correlations of ambient seismic noise indicate a long-term seismic velocity change associated with the 2006 M7.5 slow-slip event (SSE) in the Guerrero region, Mexico. Because the SSE does not radiate seismic waves, the measured velocity change cannot be associated with the response of superficial soil layers to strong shaking as observed for regular earthquakes. The perturbation observed maximized at periods between 7 s and 17 s, which correspond to surface waves with sensitivity to the upper and middle crust. The amplitude of the relative velocity change (similar to 10(-3)) was much larger than the volumetric deformation (similar to 10(-6)) at the depths probed (similar to 5-20 km). Moreover, the time dependence of the velocity perturbation indicated that it was related to the strain rate rather than the strain itself. This suggests that during strong slow-slip events, the deformation of the overlying crust shows significant nonlinear elastic behavior. Citation: Rivet,
Filiaciones:
Rivet D.:
Institut des Sciences de la Terre, CNRS, Université Joseph Fourier, BP 53, F-38041 Grenoble Cedex 9, France
Campillo M.:
Institut des Sciences de la Terre, CNRS, Université Joseph Fourier, BP 53, F-38041 Grenoble Cedex 9, France
Shapiro N.M.:
Institut de Physique du Globe de Paris, UMS 7154, CNRS, 1 rue Jussieu, F-75238 Paris Cedex 5, France
Cruz-Atienza V.:
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico
Radiguet M.:
Institut des Sciences de la Terre, CNRS, Université Joseph Fourier, BP 53, F-38041 Grenoble Cedex 9, France
Cotte N.:
Institut des Sciences de la Terre, CNRS, Université Joseph Fourier, BP 53, F-38041 Grenoble Cedex 9, France
Kostoglodov V.:
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico
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