GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.2 GNGTS 2023 Magma dynamics at Mt. Etna from continuous GNSS observations Palano M. 1 , Pezzo G. 2 , Chiarabba C. 2 1 Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania - Osservatorio Etneo, Catania, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy Understanding and constraining the source of geodetic deformation in volcanic areas is an important component of hazard assessment. To this aim, we analyzed all continuous GNSS observations collected at Mount Etna volcano (Italy) during the last two decades. Raw GNSS observations, were processed by using the GAMIT/GLOBK software and achieved results, e.g. station daily time series and network-scale surface deformation fields, have been referred to a local reference frame. By inspecting the daily baseline changes for EDAM and EMGL stations we detected a total of 59 different ground deformation phases consisting in 29 inflation phases, 21 deflation phases, 5 magmatic intrusions and 4 periods with no significant deformation. Some of the inflation and deflation phases are characterized by weak signals and perhaps poorly able to constraint elastic models. By excluding these phases as well as those characterized by magmatic intrusions (generally related to fast migration of magma toward the surface in the last 2-3 km) and/or null deformation, we computed elastic deformation models for 26 inflation and 14 deflation phases. In order to define all modeled parameters in a robust and unambiguous way over the studied period and to allow a direct comparison between the obtained results, during the modelling step a uniform approach was adopted. We integrated our results with recent tomographic models, correlating the inferred sources with V P and V P /V S anomalies, in order to provide an exhaustive interpretative model into the general volcano-tectonic context of Mt. Etna and in turn, new insight on hazard assessment.