Measuring volcanic deformation of the Galapagos Islands with InSAR

Located off the coast of Ecuador in the Pacific Ocean, the Galapagos Islands are home to some of the most active volcanoes in the world. The island chain experienced seven eruptions since 1992 from four different volcanoes. Using interferometric synthetic aperture radar (InSAR) from ERS-1, ERS-2, Radarsat-1, and Envisat satellites from 1992 to 2010, we can measure deformation at all of the active volcanoes in the Galapagos Islands. Using the small baseline subset (SBAS) method, a time history of deformation is measured at Wolf, Darwin, Alcedo, Sierra Negra, Cerro Azul, Fernandina, and Marchena volcanoes. Details of the 2008 eruption at Cerro Azul and the 2009 eruption at Fernandina are measured and constraints on the locations of the magma chambers are made using the frequent acquisitions on multiple tracks from Envisat.