TY - JOUR ID - 240536 TI - Co-Seismic Surface Displacement Induced by the Bam Earthquake, Iran (26/12/2003, M=6.6): Insights from InSAR, GPS, SPOT5 Analyses and Levelling JO - Journal of Seismology and Earthquake Engineering JA - JSEE LA - en SN - 1735-1669 AU - Peyret, M. AU - Dominquez, S. AU - Djamour, Y. AU - Avallone, A. AU - Briole, P. AU - Tavakoli, F. AU - Chery, J. AU - Nankali, H.R. AU - Doerflinger, E. AD - Laboratoire de Dynamique de la lithosphere, CNRS/Universite de Montpellier II AD - Laboratoire de Dynamique de la lithosphere, CNRS/Universite de Montpellier II and National Catographic Center, Tehran AD - IPGP, Department de Sismologie, Paris AD - National Cartographic Center, Tehran AD - Laboratoire de Dynamique de la Lithosphere, CNRS/Universite de Montpellier II Y1 - 2006 PY - 2006 VL - 8 IS - 3 SP - 145 EP - 152 KW - SAR Interferometry KW - Levelling KW - Sub-pixel correlation offsets KW - Dislocation model at depth KW - GPS DO - N2 - Co-seismic surface deformation measurements in the vicinity of a ruptured fault provide constraints on detailed fault geometry and slip distribution at depth. Together with seismological data, they give unique insights on the mechanical behaviour of a seismic fault. Three different satellite and ground geodetic measurements of Bam earthquake (Mw 6.6, December 26, 2003) induced surface deformation are presented. Envisat ASAR interferometry provides precise and dense information. However, due to this strike-slip fault orientation, sub-pixel correlation technique applied to Spot-5 images makes more explicit the horizontal component of surface deformation. We complete these oblique and horizontal estimations of deformation with a levelling profile along the main road crossing the rupture from west to east. This geodetic data allows us to propose a dislocation model at depth. The slip vector, on a quasi-vertical fault, slightly dipping towards east, has a strike-slip component as high as 2m, while the dip-slip component appears to be small. We suggest that rupture may have been initiated at depth on the Bam fault and propagated towards surface along this new fault branch. In addition to co-seismic deformation, InSAR analysis and levelling data reveal the presence of a high-rate subsiding zone south-east of Bam city. The phenomenon is likely due to heavy water withdrawal for cultivation purpose or water supply to the Bam and Baravat inhabitants. Ultimately, we present a work in progress involving GPS and InSAR which aims to map post-seismic deformation in the vicinity of Bam. However, technical problems in GPS campaigns and atmospheric artifacts in InSAR acquisitions did not enable us to show any evidence of such a deformation so far. UR - http://www.jsee.ir/article_240536.html L1 - http://www.jsee.ir/article_240536_5f8632fe602373e2acdf3b8e44db32cd.pdf ER -