Deformation due to the 2003 Bam (Iran) earthquake

On 26 December 2003, a magnitude 6.6 earthquake ruptured the upper crust directlybelow the city of Bam insoutheastern Iran. Our analysis of SAR data collected by the Envisat satellite of the European Space Agency shows that although the earthquake was very shallow (most of the seismic moment release occurred at depth of 4-5 km), essentially no slip occurred at the surface. We suggest that the 'shallow slip deficit' inferred in Bam and other recent large earthquakes is caused by a distributed failure of the uppermost crust in the time period between earthquakes.

Perspective view of the earthquake rupture and aftershocks; the surface color denotes decorrelation of the radar images


Co-seismic stress changes due to the Bam earthquake on vertical faults of variable strike, at different depths (MPEG and QuickTime movies):

Depth =2 km. MPEG-movie (1 Mb) Quicktime-movie (6.7 Mb)

# Bam slip model - homogeneous half-space (DIS3D) (DLC)

Re-construction of the 3-D surface displacement field from the SAR data:


Reference: Fialko, Y., D. Sandwell, M. Simons, and P. Rosen, Three-dimensional deformation caused by the Bam, Iran, earthquake and the origin of shallow slip deficit, Nature, 435, doi:10.1038/nature03425, 295-299, 2005

Go back