Rémy Dominique, Perfettini Hugo, Cotte N., Avouac J. P., Chlieh Mohamed, Bondoux Francis, Sladen A., Tavera H., Socquet A. (2016). Postseismic relocking of the subduction megathrust following the 2007 Pisco, Peru, earthquake. Journal of Geophysical Research : Solid Earth, 121 (5), p. 3978-3995. ISSN 2169-9313.
Titre du document
Postseismic relocking of the subduction megathrust following the 2007 Pisco, Peru, earthquake
Année de publication
2016
Auteurs
Rémy Dominique, Perfettini Hugo, Cotte N., Avouac J. P., Chlieh Mohamed, Bondoux Francis, Sladen A., Tavera H., Socquet A.
Source
Journal of Geophysical Research : Solid Earth, 2016,
121 (5), p. 3978-3995 ISSN 2169-9313
Characterizing the time evolution of slip over different phases of the seismic cycle is crucial to a better understanding of the factors controlling the occurrence of large earthquakes. In this study, we take advantage of interferometric synthetic aperture radar data and 3.5 years of continuous Global Positioning System (GPS) measurements to determine interseismic, coseismic, and postseismic slip distributions in the region of the 2007, M-w 8.0 Pisco, earthquake, Peru, using the same fault geometry and inversion method. Our interseismic model, based on pre-2007 campaign GPS data, suggests that the 2007 Pisco seismic slip occurred in a region strongly coupled before the earthquake while afterslip occurred in low coupled regions. Large afterslip occurred in the peripheral area of coseismic rupture in agreement with the notion that afterslip is mainly induced by coseismic stress changes. The temporal evolution of the region of maximum afterslip, characterized by a relaxation time of about 2.3 years, is located in the region where the Nazca ridge is subducting, consistent with rate-strengthening friction promoting aseismic slip. We estimate a return period for the Pisco earthquake of about 230 years with an estimated aseismic slip that might account for about 50% of the slip budget in this region over the 0-50 km seismogenic depth range. A major result of this study is that the main asperity that ruptured during the 2007 Pisco earthquake relocked soon after this event.
Plan de classement
Géophysique interne [066]
Description Géographique
PEROU
Localisation
Fonds IRD [F B010067737]
Identifiant IRD
fdi:010067737
