Joint GNSS-InSAR analysis of ground deformation on the eastern flank of Mount Etna.

Mount Etna is located on eastern Sicily on the border of the collision zone between the Eurasia and Nubia plate. The regional geodynamic framework is characterized by two superimposed regional tectonic domains: a compressional one oriented N-S and an extensional one oriented approximately WNW-ESE. These two domains, together with the volcano-tectonic one, generated a tectonic system which is unique in the world. It exhibits a complex system of faults prevalently on the eastern flank of the volcano, which is the most complicated in terms of interaction between the tectonic, volcano and gravitational processes. The eastern flank of Mount Etna is the most active area of the volcano in terms of deformation and seismicity, because the deformation rates are at least one order of magnitude greater than the surrounding area, due to the eastwards sliding of this flank.

The monitoring and analysis of the high deformation occurring on the eastern flank of Mount Etna is the keystone for understanding the volcano-tectonic dynamics that, apart from the tectonic and volcanic processes, it is paramount relevant because involves the instability of this flank in a densely inhabited area. In this context the Istituto Nazionale di Geofisica e Vulcanologia – Osservatorio Etneo (INGV-OE) created one of the most sophisticated and complete monitoring networks in the world in terms of number of multi-disciplinary station (seismic, geodetic, geochemistry). Since 2014, the GeoDynamic & GeoMatic Laboratory (GD&GM-LAB) of the University of Catania started to create many GNSS sub networks, belonging to the UNICT-Net, in order to determine the offsets occurring on the blocks of each fault of the eastern flank.

In order to have a complete analysis of deformation, INGV-OE and the GD&GM-LAB started to consider this area as an “open-air laboratory” where integrate GNSS and InSAR data with the twofold objective: to characterize the dynamic of this area for contributing to the volcanic hazard assessment and to identify precursor phenomena on shear structures analysing the relationship between kinematics, dynamics and volcano processes in the frame of the ATTEMPT INGV project.