SEMINAR: MGG Student Seminar - Tues Mar 2

[Scott Baker <sbaker@rsmas.miami.edu>]

MGG Student Seminar

Tuesday March 2, 2010

Cimas Conference Room

Albertus Ditya

and

Marco Bagnardi

Fernandina volcano, Galapagos: where is the magma chamber?

Study of active magmatic processes using Satellite Radar Interferometry .

At ocean island volcanoes only a fraction of the magma coming from the mantle is erupted; the remaining magma is stored in crustal magma chambers, or trapped near the crust-mantle boundary. Magma intrusions increase the pressure and inflate the volcanic edifice, triggering earthquakes and eruptions. The geometry of the magma chamber and conduits, therefore, is fundamental to the development of predictive models of volcano deformation and eruptions for any kind of volcanic hazard mitigation program.

The Galapagos Archipelago, located on the Nazca plate about 1000 km West of Ecuador, is formed by some of the most rapidly deforming ocean island volcanoes. Fernandina volcano, on the homonym island, is one of them.

Fernandina Island consists of a single volcano with a maximum elevation of 1470 meters and a central caldera nearly 1000 meters deep. Fernandina, considered one of the most active volcanoes in the world, has erupted 15 times since 1958.

We examine the deformation associated with the latest events using Interferometric Synthetic Aperture Radar (InSAR) satellite data from the European satellites ERS-1, ERS-2 and Envisat acquired over Fernandina from 1992 to 2009. SAR interferograms are then used to study spatial and temporal evolution of the deformation and to generate source models.

Our preliminary results show different sources of deformation involved during pre-eruptive, co-eruptive or post-eruptive phases, that are probably associated with different processes of magma accumulation and withdrawal.