This example presents our study on the differential interferomatric SAR technique for the assessment of the crustal motions, related to the Mw.:7.3 Antofagasta, Chile subduction earthquake that occurred on the 30. July 1995. The used data set consists of 5 Single Look Complex products, in which there is a data set from Tandem Mission. This data set covers an area of 300 km in along track and 100 km in across track near the peninsula Meijllones. The tandem mission data set acquired on the 31.03.1996 and 01.04.1996 was used for generation of the topography. Using the second data set (16.04.95-30.07.95) the co-seismic deformation was detected. After the earthquake we expect: post-seismic visco-elastic relaxation of the lower crust or upper mantle or aseismic slip along the seismogenic interface (subduction zone, upper 50 km) using the third data set of 8 months after event (30.7.95-31.3.96). This post-seismic deformation appears to have its maximum at the surface in the inner forearc i.e. not at the coast.