BOLETÍN DE LA SOCIEDAD GEOLÓGICA MEXICANA
http://dx.doi.org/10.18268/BSGM2011v63n1a1 |
Aplicación de DInSAR a los estudios de subsidencia en el Valle de Mexicali
Application of DInSAR to subsidence studies in the Mexicali Valley
Olga Sarychikhina1*, Ewa Glowacka1, Francisco Suárez Vidal1, Robert Mellors2 y Jorge Ramírez Hernández3
1 División de Ciencias de la Tierra, CICESE, Carret. Ensenada–Tijuana No. 3918, Zona Playitas, Ensenada, 22860, B.C., México.
2 Department of Geological Sciences, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182, USA.
3 Instituto de Ingeniería, UABC, Blvd. Benito Juárez y calle de la Normal s/n, Col. Insurgentes Este, Mexicali, 21280, B.C., México
* This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract
It is widely known that geothermal fluid extraction is frequently accompanied by ground subsidence which reaches dozens of centimeters per year. In the Cerro Prieto geothermal field, located in the Mexicali Valley, the subsidence caused by geothermal fluid extraction reaches the rate of 18 cm/yr and is causing damage to infrastructure like roads, railroad tracks, irrigation channels, and agricultural fields. In this paper, Differential Interferometry of Synthetic Aperture Radar (DInSAR) data were used and compared with historic precise leveling data, continuous observation of geotechnical instruments installed in the area, and data from geotectonic field mapping to determine the area, limits and rate of subsidence.
The results of this study suggest that the area of subsidence is limited by faults: Imperial, Cerro Prieto, Saltillo and Morelia; area also known as Cerro Prieto basin, so the area of subsidence is larger than the area of Cerro Prieto geothermal field. The comparison of subsidence rates obtained by leveling for 1994–1997 and DInSAR method for 2006–2007 allow to determine the subsidence dynamic and relate it with changes in geothermal fluid extraction rate in the Cerro Prieto geothermal field.
Keywords: DInSAR, subsidence, Mexicali Valley, geothermal field, Cerro Prieto, fluid extraction.