APPLICATION OF RADAR INTERFEROMETRY TO THE DETECTION OF SURFACE DEFORMATION IN SOUTHERN CALIFORNIA

摘要

Interferometric synthetic aperture radar (InSAR) is applied to 2003-2010 Envisat data collected over Imperial Valley in southern California. The study area is characterized by ongoing regional extension, localized tectonic deformation, high heat flow, significant earthquakes and seismic swarms, and aseismic slip. Conventional differential InSAR fails in most of this area, due to extensive agriculture. Using the SqueeSARTM technique developed at TRE Italy, significant surface deformation is detected within all current geothermal fields - Salton Sea, Heber, North Brawley and East Mesa. Ground-based annual levelling measurements available for two of the geothermal fields agreed well with the SqueeSAR measurements. Differential movements on both sides of faults were also observed, associated with ongoing fault movements. In addition, clearly seen on one of the faults is a triggering effect from a nearby M7.2 earthquake in April 2010, as well as displacements associated with a local aseismic event in October 2006.