GNGTS 2017 - 36° Convegno Nazionale

90 GNGTS 2017 S essione 1.1 available focal mechanisms), we computed the rock volumes involved during the earthquake nucleation process and delimited between the Mt. Vettore main fault and by an antithetic fault, as suggested by earthquakes hypocentral distribution. In particular, in this work we estimated both the collapsed rock volume and the consecutive uplifted rock volume. In fact, DInSAR results highlight two different ground deformation within the hangingwall block: a larger zone and a smaller area affected by significant subsidence phenomena and by uplift processes, respectively. The Amatrice-Norcia seismogenic area is inserted in the tectonic setting of the Umbria-Marche Apennine. The seismic sequence began with the M w 6.0 Amatrice earthquake, nucleated on August 24, 2016 along the Mt. Gorzano extensional fault (e.g., Lavecchia et al. , 2016). Then, on October 26, two seismic events, occurred with M w 5.4 and M w 5.9 respectively, nucleated nearby Ussita and Visso (Chiaraluce et al. , 2017), activating another major fault called the Mt. Vettore Fault System. Finally, on October 30 (at 06:40 UTC) the largest event of the sequence, with M w 6.5, occurred near the town of Norcia along the Mt. Vettore Fault System. At the moment, the seismic sequence is still active. The Mt. Gorzano Fault and the Mt. Vettore Fault System can be considered as the main seismically active extensional faults in the area and are associated to numerous historical and instrumental earthquakes which occurred in this area in the previous centuries (e.g., Galadini and Galli, 2003; Galli et al. , 2008). The Mt. Gorzano Fault is a ~30 km long SW-dipping (~60-70°) active extensional fault (e.g., Galadini and Galli, 2003; Smeraglia et al. , 2017) exposed in the Amatrice area along the foothills of Mt. Gorzano. The Mt. Vettore Fault System is a ~18 km long active fault system consisting of a series of SW-dipping (34-75°) extensional faults exposed on the flanks and along the foothills of Mt. Vettore, Mt. Porche, and Mt. Bove (e.g., Galadini and Galli, 2003). Fig. 1 - a) Deformation map of the Norcia area, extracted by multi-temporal InSAR processing, showing both subsiding and uplifting areas. Associated cross-sections across the subsiding area showing ground subsidence pattern. b) Deformation map of the Norcia area, extracted by multi-temporal InSAR processing, showing both subsiding and uplifting areas. Associated cross-sections across the uplifting area showing ground uplift pattern.