GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.1 - POSTER GNGTS 2023 Study of the seismic sequence in the Umbro-Marche Apennines offshore by means of the b -value evolution A. Figlioli 1 , A. D’Alessandro 2 , R. Martorana 1 , A. Sulli 1 , G. Vitale 2 1 Università degli studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Palermo, Italia 2 Istituto nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale dei terremoti, Roma, Italia Introduction On 9 November 2022 an earthquake occurred offshore of The Marches area with a magnitude of 5.7 Mw and a depth of 6 km. It affected nearest towns such as Pesaro and Ancona. The tectonic structure that generated the seismic event is the Pesaro sea-Cornelia. It is part of the external offshore thrust of the Umbro-Marche Apennines. This front is the NE-verging fault system at the eastern border of the Northern Apennine chain, parallel to the Marche coast. Figure 1.a) Map showing the main geological and structural features in and around the study area (Maesano et al., 2013), b) Frequency distribution magnitude of the Marches offshore to range 2005-2022, c) Seismicity distribution about sequency from 9 November to 28 November.