3-D observations of deformation due to the M w 6.5 Bam (Iran) earthquake, and the origin of the shallow slip deficit in review in Nature, 2004

We derive the full vector displacement field due to the M w 6.5 Bam (Iran) earthquake using radar data from the Envisat satellite of the European Space Agency. Analysis of surface deformation indicates that most of the seismic moment release along the 20-km-long strike-slip rupture occurred at a shallow (4-5 km) depth, yet the rupture did not break the surface. The Bam event is therefore an end-member case of a shallow slip deficit model postulating that the coseismic slip in the uppermost crust is systematically less than that at the seismogenic depth (4-10 km). The InSAR-derived surface displacement data from the Bam and other large shallow earthquakes suggest that the uppermost section of the seismogenic crust around young and developing faults may undergo a distributed failure (thereby accumulating little elastic strain) in the interseismic period.

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