Insights from 17 years of geodetic and petrological observations at Mt. Etna volcano (Italy): definition of a long-term pattern of magma transport and storage

During the last two decades, a number of large eruptive events (e.g., 2001, 2002-03, 2004-05, 2006, 2008) as well as more than 100 paroxysmal events (from moderate to intense and impulsive explosive activity, coupled sometime to voluminous lava flows) occurred at Mt. Etna volcano. These events involved the upper sector of the northern and southern flanks of the volcano, along with the summit craters. By careful inspecting the daily displacement on selected continuous GPS stations installed on the upper part of the volcano edifice, we proposed an unprecedented and detailed resolution of different deformative episodes occurring at Mt. Etna. The surface deformation for each detected stage was used to constrain isotropic half-space elastic inversion models. In addition, a number of petrological observations on volcanic rocks (lavas and tephra), which were collected on the field during the on-going eruptive activity, provided relevant constraints on the timescales of magma storage and transfer at various levels of the volcano plumbing system. The joint interpretation of constraints coming from geodetic data and petrological observations allowed us to provide an updated model of the magma ascent history and of the complex interactions that affected various magma batches during the whole investigated period.