We use Synthetic Aperture Radar Interferometry (InSAR) from satellites to measure earthquake deformation. InSAR earthquake deformation maps (interferograms) are obtained from the phase difference of two radar images, acquired before and after an earthquake. The maps show how the ground permanently moved towards or away from the satellite. We simulate the observations using a simple earthquake model consisting of dislocation surfaces embedded in elastic half-space. The optimal dislocation parameters tell us where the fault is located and how much slip occurred.
Two examples of earthquake deformation studies will be presented. In the former study we analyzed observations of the Hector Mine earthquake (magnitude 7.2) that occurred in Mojave Desert, Southern California, in October 1999. In the second study we looked at two earthquakes (magnitude 6.5) that occurred only 4 days apart in South Iceland in June 2000.