Crustal deformation associated with the northern Miyagi earthquake detected by RADARSAT-1 and ENVISAT SAR interferometry

摘要

We applied synthetic aperture radar (SAR) interferometry to map the deformation field of the northern Miyagi earthquake (M6.4) which occurred on July 26, 2003. RADARSAT-1 and ENVISAT satellite data were processed to show the deformation field associated with the earthquake. This is the first observation of the crustal deformation associated with an earthquake detected by ENVISAT SAR interferometry. The 2.5-dimensional displacement near the epicenter was revealed by the combination of RADARSAT-1 and ENVISAT interferograms. The 2.5-D displacement vectors are consistent with the fault model proposed by Nishimura et al. (2003). The InSAR displacement fields show that the boundary of the uplifted and subsided areas is located not along the Asahiyama flexure but 3-4 km east of the flexure. Therefore, the source fault of the earthquake may have little relation to the Asahiyama flexure.