GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.1 GNGTS 2023 Evaluation of tsunamigenic hazard through numerical modeling from seismic and non-seismic sources in the Crotone offshore (Calabria, Southern Italy) F. Zaniboni 1,3 , C. Angeli 1 , A. Argnani 2 , Antoncecchi I. 5 , Di Bucci D. 4 , Fagiani A. 5 , G. Gallotti 1 , L. Lipparini 3 , I. Molinari 3 , M. Rovere 2 , G. Sgattoni 3 , G. Vico 5 , M. Zanetti 1 , A. Armigliato 1 1 Dipartimento di Fisica e Astronomia “A. Righi”, Università di Bologna, Bologna, Italy 2 ISMAR – CNR, Bologna, Italy 3 INGV - Sezione di Bologna, Bologna, Italy 4 Dipartimento della Protezione Civile, Rome, Italy 5 Italian Ministry of Environment and Energy Security – Division V, Rome, Italy Tsunamis in the Mediterranean Sea can be considered among the major sources of hazard, both for the extension of the area that can be involved by the water impact and for the closeness of potential sources to the coast, which reduces dramatically the alert and evacuation time. Moreover, landslides, as other non-seismic tsunami sources, are often characterized by a lack of precursors (such as seismic shaking), a reason for which the ensuing waves are sometimes called “surprise tsunamis”. Numerical simulations can first quantify the coastal stretch extension and the size of the tsunami impact on coastal buildings and infrastructures. The University of Bologna Tsunami Research Team has developed in the years a set of numerical codes simulating the different phases of the phenomenon, both for seismic and for non-seismic sources: for the former, the hypothesized seismogenic fault provides the instantaneous impulse for the wave propagation; for the latter, the landslide stability is studied, also taking into account the possible seismic trigger, whereas the simulation of the slide dynamics supplies the time-dependent forcing for tsunami propagation. In both cases, then, wave propagation in the marine water body and coastal flooding are mimicked by solving the hydrodynamic equations through numerical techniques. This numerical approach has been applied to many cases (see the recent publications by Gasperini et al., 2022; Gallotti et al., 2021; Zaniboni et al., 2021, and further references therein). The “H&RA Lacinia project”, funded by the Italian Ministry of Environment and Energy Security, aimed at developing a methodology to study natural hazards potentially triggered by offshore production activities. In this framework, the area offshore Crotone (Ionian Calabria coast, Southern Italy) has been chosen as a test site.