GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 MS3_Etna Project: planning of the investigation for the definition of zones susceptibility to ground instabilities due to co-seismic fracturing ETNA FAC+MS Working Group Center for Seismic Microzonation and its application The main goal of the third-level seismic microzonation studies (MS3 from the Italian acronym) of 23 municipalities located in the Mt. Etna region, in eastern Sicily, is the definition of the zones of susceptibility to ground instabilities connected to the active and capable faults (FAC from the Italian acronym) of the area. The study, provided by the Center for Seismic Microzonation and its applications on behalf of the Regional Department of Civil Protection, is focused on the mitigation of the risks associated with the repeated episodes of ground fracturing characterizing the seismic history of the region. The seismotectonic framework of Mt. Etna derives from the concurrent factors connected to the regional tectonics, the effects of the deformation due to the inflation/deflation cycles of the volcano and the gravitational instability of the volcanic edifice. As a consequence, the area is affected by low magnitude, surficial earthquakes producing marked ground fracturing phenomena with diffuse damage to the buildings. For the definition of the zones prone to instability due to co-seismic fracturing, the construction of deformation models along the FACs is thus necessary. The expected results of the study are: i) the definition of the geometric relationships between deep seismogenic structures and ground fracture systems, ii) the genetic classification (tectonic, volcanotectonic and gravitative) of the different type of fracture systems of the etnean region, iii) the definition of protocols for data acquisition and processing useful for future MS studies.