Subsidence Monitoring in Imperial Valley, California, Using Satellite Radar Interferometry

Abstract

We are in the process of applying interferometric synthetic aperture radar (InSAR) techniques to the monitoring of surface subsidence associated with geothermal production in the Imperial Valley of southern California. Subsidence may increase over the next decade as a result of enhanced geothermal production in the region. InSAR is a cost-effective technique for detecting and mapping surface deformation that allows semi-continuous monitoring of large areas, thus potentially overshadowing in the future the time-consuming, area-limited, and expensive land-based methods. There are several types of data that will be used in this project, of which we have started with existing data from the ERS satellites (1992-2000) collected over the Salton Sea geothermal field. Since traditional InSAR is limited in vegetated areas, a permanent scatterers technique (PSInSAR) is being used that is likely more suitable in agricultural areas. We collaborate closely with the geothermal operators who provide proprietary leveling data for comparison. We expect that our InSAR results will demonstrate economic viability, ease of application, and efficient feedback to the geothermal industry in their monitoring and mitigation efforts.