HR: 1340h
AN: S13A-1054    [Abstracts]
TI: Overview of the August 15th, 2007 Pisco Earthquake (Mw=8.0), Central Peru.
AU: * TAVERA, H
EM: hjtavera@geo.igp.gob.pe
AF: Instituto Geofisico del Peru, Calle Badajoz 169 Urb. Mayorazgo, 4ta Etapa, Lima, Ate, Peru
AU: Perfettini, H
EM: perfetti@lmtg.obs-mip.fr
AF: LMTG-UNIVERSITE DE TOULOUSE-CNRS-IRD-OMP, Observatoire Midi Pyrenees 14, avenue Edouard Belin, Toulouse, 31400, France
AU: Audin, L
EM: laurence.audin@ird.fr
AF: LMTG-UNIVERSITE DE TOULOUSE-CNRS-IRD-OMP, Observatoire Midi Pyrenees 14, avenue Edouard Belin, Toulouse, 31400, France
AU: Bernal, I
EM: ibernal@axil.igp.gob.pe
AF: Instituto Geofisico del Peru, Calle Badajoz 169 Urb. Mayorazgo, 4ta Etapa, Lima, Ate, Peru
AU: Farber, D
EM: dfarber@ucsc.edu
AF: Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95063, United States
AU: Farber, D
EM: dfarber@ucsc.edu
AF: Lawrence Livermore National Laboratory, LLNL, Livermore, 94550, United States
AU: Bondoux, F
EM: francisbondoux@vtr.net
AF: LMTG-UNIVERSITE DE TOULOUSE-CNRS-IRD-OMP, Observatoire Midi Pyrenees 14, avenue Edouard Belin, Toulouse, 31400, France
AU: Sladen, A
EM: sladen@gps.caltech.edu
AF: Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States
AU: Avouac, J
EM: avouac@gps.caltech.edu
AF: Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States
AB: With 7 subduction related earthquakes of ~Mw=8.0 during the 20th century, Central Peru is one of the most seismogenic areas in the world. On August 15th, 2007 a large subduction related earthquake (Mw=8.0, GCMT), occurred along the coast of Central Peru, near the town of Pisco. The earthquake was felt as far as 600km away from the epicenter and produced extensive damage in Pisco, where the intensity reached a maximum of Imax=VII (MM), and. Accelerometric records in Lima, 250 km, away from the epicenter, indicate up to 110 cm/s2 peak acceleration. Records from Ica, 80 km from the epicenter, indicate a peak acceleration of 488 cm/s2 on the EW component. Closer to the epicentral area ground shaking was severe enough to produce extensive liquefaction and ground rupture along the coast. First motion polarities indicate a thrust event with a dip angle of about 14°, which is somewhat steeper than the estimated dip angle of the subduction interface in the area. Waveform modeling shows that in fact, the source consists of 2 sub-events. The early afershock distribution well delineates these events which ruptured a portion of the trench that was left unbroken by the more recent 1942 earthquake (Mw 8) to the south, and the 1974 earthquake (Mw 8) to the north. Historic records indicate that the portion of the subduction zone which ruptured August 15th, 2007 had not experienced any comparable or larger rupture since at least 1746 and possibly 1687, which is remarkable given that the local convergence rate between the Nazca and South America plate ( 6-8 cm/yr).
DE: 7209 Earthquake dynamics (1242)
DE: 7215 Earthquake source observations (1240)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Seismology [S]
MN: 2007 Fall Meeting