GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 Methodology An analysis of geological structures in the study area was conducted, aimed at better characterizing the potential seismogenic faults, and of an important submarine sedimentary body potentially unstable from a gravitational point of view, and therefore susceptible to activation or reactivation following earthquakes generated by the aforementioned faults. This analysis was followed by an assessment of the potential impact and consequent losses caused by earthquakes and tsunamis potentially generated by the recognized structures, both faults and landslides. With regard to earthquakes, different impact and loss scenarios have been developed, starting with damage to residential buildings and major infrastructures due to the potential activation of seismogenic faults. With regard to tsunamis, the characterization of the vulnerability of residential buildings and of the main infrastructures present in the study area (hospitals, buildings for industries, etc.), including civil networks (bridges, viaducts, primary infrastructures of the electricity system, etc.) was deepened. The presence of potentially vulnerable cultural heritage was also considered. On this basis, tsunami impact and loss scenarios were developed. Finally, variations in the stress values induced by the exploitation activities were investigated through the creation of a dynamic model, analysing whether the stress propagates in the studied crustal volume (and with what intensity) and if a potential interaction with the identified faults can be envisaged. Results All research activities ended in October 2022 achieving the following results: Calculation of georeferred seismic shaking scenarios potentially determined by some faults present in the area using (i) classical methods, such as shake maps also with finite faults, and (ii) numerical hybrid broadband methods for shaking simulations in three-dimensional crust models and with finite fault models, obtaining the entire time series of shaking in a wide frequency spectrum (broadband). Analysis, definition and mapping of some landslides along the coastline in the area of interest – AOI (Fig. 2), defining for each of them geometry, evolution and interested volume, along with some key parameters as: detachment zone and its dimensions, distance from the coast, distance from the main faults identified in the AOI, rheology and kinematics. 3D geological static model, dynamic simulation of the gas production, stress fields analysis. Numerical modelling of the coastal slopes and generation, propagation, flooding on the coast of tsunamis generated by some of the offshore landslides and faults recognised in the AOI.