Synthetic normal faulting of the 9 January 2008 Nima (Tibet) earthquake from conventional and along‐track SAR interferometry

[1] We use Synthetic Aperture Radar Interferometry (InSAR) to derive the coseismic deformation field of the 9 January 2008 Nima (Tibet) earthquake. The results show an asymmetric deformation pattern, consistent with normal faulting on a NW-dipping fault plane. The complex line-of-sight (LOS) fringe pattern suggests that a second, synthetic fault in the hanging wall of the mainshock rupture slipped during the event, most likely during the largest aftershock. We use conventional and along-track InSAR data to invert for the geometry and the slip-distribution on the two fault planes. The focal mechanisms of the mainshock and its largest aftershock show normal faulting with a small left-lateral strike-slip component near the NE-trending Riganpei Cuo fault, which is consistent with our InSAR observation and inversion result. This event suggests that normal faulting in addition to previously established conjugate strike-slip deformation in the region contributes to the internal deformation of central Tibet.

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