Horizontal coseismic deformation of the 2003 Bam (Iran) earthquake measured from SPOT‐5 THR satellite imagery

[1] On 26 December 2003, a destructive Mw 6.5 earthquake occurred in Kerman province, Iran, killing more than 30,000 people around the ancient city of Bam. We map the fault zone and determine the slip distribution using sub-pixel correlation of images taken by the SPOT-5 THR sensor before and after the main shock. Our results show that the surface displacement occurred on a blind fault oriented N174 and located South of Bam. A 15 km along-strike profile depicts a distribution with a maximum displacement of 1.2 ± 0.15 m near the centre of the fault. The mean slip that we infer (∼0.77 ± 0.05 m) is much higher than the ground displacement measured in the field (∼0.2 m). We suggest that field-measured displacements are underestimated due to slip accommodation within an 500 m wide shear zone. Furthermore, we demonstrate for the first time the relevancy of 2.5 m SPOT-5 THR images for sub-pixel ground displacement measurements.

[1]  Eric J. Fielding,et al.  Aseismic deformation of a fold-and-thrust belt imaged by synthetic aperture radar interferometry near Shahdad, southeast Iran , 2004 .

[2]  C. Latry,et al.  Super resolution: quincunx sampling and fusion processing , 2003, IGARSS.

[3]  Christopher H. Scholz,et al.  Scaling laws for large earthquakes: Consequences for physical models , 1982 .

[4]  T. Wright,et al.  The 2003 Bam (Iran) earthquake: Rupture of a blind strike‐slip fault , 2004 .

[5]  D. Wells,et al.  New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement , 1994, Bulletin of the Seismological Society of America.

[6]  Rémi Michel,et al.  Horizontal coseismic deformation of the 1999 Chi-Chi earthquake measured from SPOT satellite images: Implications for the seismic cycle along the western foothills of central Taiwan , 2003 .

[7]  J. Avouac,et al.  Measuring earthquakes from optical satellite images. , 2000, Applied optics.

[8]  T. Wright,et al.  The 1998 March 14 Fandoqa earthquake (Mw 6.6) in Kerman province, southeast Iran: re‐rupture of the 1981 Sirch earthquake fault, triggering of slip on adjacent thrusts and the active tectonics of the Gowk fault zone , 2001 .

[9]  N. Ambraseys,et al.  A history of Persian earthquakes , 1982 .

[10]  Frederic Masson,et al.  Present‐day crustal deformation and plate kinematics in the Middle East constrained by GPS measurements in Iran and northern Oman , 2004 .

[11]  J. Avouac,et al.  Deformation due to the 17 August 1999 Izmit, Turkey, earthquake measured from SPOT images , 2002 .

[12]  E. Breton,et al.  SPOT5 geometric image quality , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[13]  James Jackson,et al.  Offset and evolution of the Gowk fault, S.E. Iran: a major intra-continental strike-slip system , 2002 .