GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.1 - POSTER GNGTS 2023 A multidisciplinary approach to building a 3D lithospheric model of the Sicily Channel Carollo A., Sulli A., Gasparo Morticelli M. Department of Earth and Sea Sciences (DiSTeM), University of Palermo, Italy Introduction The Sicily Channel is a portion of the Mediterranean Sea in which three main tectonic elements are identified: i) the Apenninic-Maghrebian chain, ii) the foreland of Gela, iii) the Iblean-Pelagian foreland, which emerges in south-western Sicily, continues in the southern Sicily offshore and eastwards into the Ionian Sea ( Sulli et al., 2000 ). The recorded seismic activity of the Sicily Channel presents deep hypocentres, ranging from 10 to 20 km; for these events, the higher local magnitude (ML) recorded is approximately 3.5 ( Chiarabba et al., 2005; Galea, 2007 ). The seismicity is low in the proximity of the southern coast of Sicily, while it is higher among the Pantelleria, Malta, and Lampedusa graben ( Calò e Parisi, 2014 ). This work aims to create a detailed 3D lithospheric model of the Sicily Channel using a multidisciplinary approach, to evaluate the elements of hazard and geological risk that affect the Iblean foreland integrating refraction seismic, reflection seismic, and seismicity data, bathymetry, and main active faults. Methods and results This study is based on the analysis and revision of the available geological and geophysical data of the Sicily Channel. The research includes (Fig. 1) data of multichannel reflection seismic profiles with different resolutions and penetration (CROP line and grid zone G seismic reflection lines of Minister of Industry of Italy, VIDEPI project), well-log data (VIDEPI project and Geothopica database), seismic refraction tomography data and seismicity data related to earthquakes recorded from 2005 to 2021 with magnitude>3 (from the INGV bulletin and ISC catalogue). A geological interpretation was carried out on the seismic profiles according to the global crustal model defined by Mooney et al., 1998 (CRUST 5.1), which is based on seismic refraction data. In this work, six horizons (out of a total of eight delineated in the CRUST 5.1 model) have been recognized according to the lithological properties and P-waves velocity values. The identified horizons, from top to bottom: 1) soft (unconsolidated) sediments with Vp 2.4 km/s; 2) hard (consolidated) sediments with Vp 4.6 km/s; 3) crystalline upper crust with Vp 6.0 km/s; 4) crystalline middle crust with Vp 6.5 km/s; 5) crystalline lower crust with Vp 7.1 km/s; 6) uppermost mantle with Vp 8.2 km/s.