Measuring deformation associated with magmatic processes at Cerro Azul Volcano, Galapagos Islands, Ecuador with InSAR

The Galapagos Islands are an active volcanic island chain in the eastern Pacific Ocean off the west coast of Ecuador. Cerro Azul volcano is located on the southern tip of Isabella Island and experienced two eruptions in 10 years. The eruptions started on September 15, 1998 and May 29, 2008 and lasted 51 days and 20 days respectively. Using radar data from Radarsat-1 and Envisat satellites, the deformation before, during, and after these eruptions was measured using interferometric synthetic aperture radar (InSAR). Radarsat-1 data cover the 1998 eruption and Envisat data is available in 2008. Compared to the 2008 data, the time coverage for the 1998 eruption is not as frequent, but still allows for measuring the deformation during the eruption. Continuous radar data coverage between the eruptions allows us to see the state of the volcano leading up to the 2008 eruption. Using data from 8 different Envisat tracks in 2008, we measured the deformation associated with two separate eruptive phases of the volcano. Acquisitions on May 30 and 31, and June 2, 3, 5 and 6 show the deformation associated with the intrusion of magma responsible for fissures on the SE flank ceased by June 5, 2008. Using these data, it is possible to measure the amount of deformation during each of the eruptive phases and model the source processes at those times.