GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 Focus on the seismic behavior of the Morrone Fault: the Majella-Morrone experiment M. Anselmi 1 , S. Bagh 1 , C. Chiarabba 1 , P. De Gori 1 , R. Fonzet 3 , A. Govoni 1 , I. Menichelli 1,3 , G. Pezzo 1 , G. Saccorot 1 , F. Silverii 1 1 Isttuto Nazionale di Geofsica e Vulcanologia, Roma, Italy 2 Isttuto Nazionale di Geofsica e Vulcanologia, Pisa, Italy 3 Università degli Studi di Roma Tre, Roma, Italy In the framework of the PON-GRINT project, a working group of INGV researchers, along with some Ph.D. students, carried out a passive seismic experiment, stll ongoing. The feld actvites began in May 2022 in the Abruzzi region (Central Italy). Between May and October 2022, twenty- three (23) temporary seismic statons were deployed in a ~ 250 km 2 area extending from the Sulmona-Pratola Peligna plain to the eastern fank of Monte Morrone. The locaton of the study area is in the Central Apennines, southeast of the area struck by the 2009 L’Aquila seismic sequence. The whole Apennine chain consists of thrust and fold systems, the space-tme E and NE migraton of which are related to the westward subducton of the Adriatc lithosphere and its progressive eastward fexural retreat (Patacca et al. 2008 and references therein). Since the Pliocene, and during the entre Quaternary, the chain was afected by extensional tectonics, contemporaneous to its signifcant uplif (Galadini et al. 2003a and references therein). The extensional faults have resulted in the formaton of several intermontane basins (e.g. the Fucino, Sulmona, L’Aquila) that are flled by contnental deposits of Plio-Quaternary age (Bosi et al. 2003; Galadini and Messina 2004). In partcular, the Apennine sector focused in this study, located in the southern-eastern Abruzzi region, has been struck by some large magnitude earthquakes , i.e. the seismic events of 1706 (Maw = 6.6) and 1933 (Maw = 5.7), as well as by the shocks of the 1349 and 1456 seismic sequences (Maw = 6.6 and 7.0, Romano et al. 2013 and references therein). The literature available indicates also the 1456, 1706 and 1933 earthquakes originated in this area (Galadini and Galli 2007; Fracassi and Valensise 2007). Many studies have been carried out to defne the seismotectonic characteristcs of this Apennine sector. Some probably actve faults have been detected along the south-western slopes of Mt. Morrone (Bosi 1975), and in the area located between Mt. Morrone, the Maiella Massif and the Cinque Miglia plain. Although the last 20 years have been characterised by low-magnitude seismicity, the presence of the Morrone Fault (whose instrumental seismic actvity is stll debated) motvates the carrying out of the experiment to record the microseismicity occurred in the whole area and also the eventual seismic actvity released by the Morrone Fault structure.