GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.2 GNGTS 2024 The current unrest of Campi Flegrei caldera: seismicity and ground deformaton Anna Tramelli and A. Benincasa, F. Bianco, A. Bobbio, C. Buonocunto, S. Caliro, A. Caputo, V. Convertto, P. Cusano, G. Dalla Via, P. De Martno, D. Delle Donne, R. Esposito, S. Gammaldi, G. Gaudiosi, D. Galluzzo, S. Guardato, D. Lo Bascio, R. Manzo, R. Nappi, L. Nardone, M. Orazi, R. Peluso, S. Petrosino, M.G. Soldovieri P. Ricciolino, G. Scarpato, M.A. Di Vito Isttuto Nazionale di Geofsica e Vulcanologia, Sezione di Napoli, Osservatorio Vesuviano, Via Diocleziano 328, Napoli, Italy Campi Flegrei is one of the areas with the higher volcanic risk in the world due the actve volcanic feld and the presence of almost 500.000 people living in the area that could be invaded by pyroclastc fow in case of erupton. Its morphology is dominated by a large caldera collapsed during two caldera-forming eruptons. The caldera includes a contnental sector and a submerged part, the Pozzuoli gulf. The caldera foor is punctuated by tens of craters’ remains of monogenic volcanic actvity origins. The Campi Flegrei area is characterised by intense uplif periods followed by subsidence phases (bradyseism). The area of the maximum uplif is located at Pozzuoli town and it decreases with a radially symmetrical shape. The uplif phases are associated with the unrests and are accompanied by seismicity that is usually shallow and with low-to-moderate magnitude. The Campi Flegrei caldera is currently in an unrest phase started at the end of 2005 when the subsidence phase, started at the end of 1984, was interrupted and the central part of the caldera started to uplif again. This trend persisted up tll now with a varying rate. The increments in the velocity of the uplif are ofen associated with an increment in the earthquake occurrence rate. In February 2022 the uplif at Pozzuoli exceeded the maximum level reached at the end of the last bradyseseimic crisis (1982-84). Between August and September 2023 an increment in the recorded seismicity in terms of rate and maximum magnitude was recorded. At the end of this period, 21-23 September, the uplif sufered an acceleraton: almost 1 cm in 3 days. The rate of the earthquakes per month with MD>=2.0 passed from 5 between January and July 2023 to almost 20 in August and September. On September 27th a MD=4.2 was recorded by the seismic network of the INGV- Osservatorio Vesuviano. This is the highest magnitude earthquake recorded in the area since 1980. The increment in the seismicity alerted the populaton and triggered a governatve mitgaton plan. At the same tme the scientfc community, already engaged in monitoring, focused even