GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 1.2 101 SLOW SLIP EVENTS AT MT. ETNA VOLCANO M. Palano 1 , F. Sparacino 1 , P. Gambino 2 , N. D’Agostino 3 , S. Calcaterra 2 1 Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Osservatorio Etneo, Catania, Italy 2 Italian Institute for Environmental Protection and Research (ISPRA), Rome, Italy 3 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy Mt. Etna is a basaltic Quaternary volcano located on the east coast of Sicily (South Italy) at the front of the Apennine-Maghrebian chain (Fig. 1). The volcano developed over the last 500 ka over metamorphic and sedimentary rocks on its western and northern slopes and over Quaternary plastic clays. The different geomechanical properties of these rocks coupled with the inhomogeneous long-term updoming of the volcano have produced a complex basement topography dominated by a 17 km-wide horseshoe-shaped depression beneath the eastern flank. Such a complex basement topography gently dips in SE direction and would lead to the large-scale seaward motion of the eastern flank of Mt. Etna as clearly documented since the early 1980s. At the surface, the unstable sector is defined by a 25 km-wide horseshoe- shaped region, which encompass the sedimentary depression and is bounded by the “NE Rift - Pernicana fault” and by the “South Rift - Mascalucia-Tremestieri - Aci Trezza fault system”, respectively on its NE and SE half (Fig. 1). We detected a set of slow slip events (SSE) occurred at Mt. Etna volcano during the 2006- 2016 period by analysing the GNSS observations collected by the continuous networks: • Etn@net, managed by the “Osservatorio Etneo” department of “Istituto Nazionale di Geofisica e Vulcanologia” and established since November 2000 (blue dots in Fig. 1). Fig. 1 - Simplified tectonic map of Mt. Etna and its eastern off-shore. Bathymetry is from www.emodnet-bathymetry. eu. cGNSS stations covering Mt. Etna volcano are reported as colored points. Abbreviations are as follows: PF, Pernicana fault; MTF, Mascalucia-Tremestieri fault; ATF, Aci Trezza fault; ESEL, ESE lineament. Inset: sketch map of eastern Sicily; AMC, Apennine-Maghrebian chain; HF, Hyblean Foreland; GCF, Gela-Catania Foredeep.