GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.1 - POSTER GNGTS 2023 Fig. 1 Map of the study area with the capable active faults (red lines) taken from the Fault2SHA CAD (Faure Walker et al., 2020); the historical (circles) and major instrumental earthquakes (stars) are also plotted (reproduced from Moratto et al., 2023).  We apply the Probabilistic Seismic Hazard Analysis (PSHA) and compute Physics-Based Simulations (PBS) of ground motion for three dams in the Campotosto area (Central Italy). The dams, which confine an artificial water reservoir feeding hydroelectric power plants, are located in an active seismic zone between the 2009 L’Aquila and 2016-2017 Central Italy seismic sequences (Fig. 1). The PSHA is performed following the approach of seismotectonic probabilism by modelling fault sources (Chartier et al., 2019). The disaggregation of the probabilistic seismic hazard, calculated for the return period of 2475 years (Fig. 2), corresponding to the collapse limit state for critical facilities, provides the magnitude-distance pair of M W =6.75±0.25 within the first 10 km of distance. This magnitude-distance pair represents the most influencing earthquake for the hazard estimate in the study area. Fig. 2 a) The contribution of the sections utilized in PSHA, for each PGA level, to the probability of exceedance (POE) of that PGA level; the black lines correspond to the 475 and 2475 years return period. b) The PGA map for the 2475 years return period and the sections (thicker lines) of the faults that contribute most to the hazard of the Campotosto site (PGA 0.816 g) and surroundings for that return period; blue and light blue lines evidence different fault sources (reproduced from Moratto et al., 2023).