GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 1.2 115 MAGNETIC INVESTIGATION AT VULCANO ISLAND: PRELIMINARY RESULTS FROM A MULTIDISCIPLINARY GEOPHYSICAL SURVEY S. Scudero 1 , S. Bongiovanni 2 , A. D’Alessandro 1 , A. Figlioli 2 , R. Martorana 2 , S. Speciale 1 , A. Pisciotta 3 , G. Vitale 1 1 Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy 2 Università di Palermo, Dipartimento di Scienze della Terra e del Mare, Palermo, Italy 3 Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Palermo, Italy Introduction. From the end of June 2021, changes in the monitored parameters (temperature, gas emission, seismicity, ground deformation) clearly indicate the beginning of a phase of unrest at Vulcano Island (Aeolian Islands, Italy). The anomalies consist in high temperatures of the fumaroles, increase of gas emissions from fumaroles and soils (both CO 2 and SO 2 ), ground deformation, and increased seismicity (Inguaggiato et al. , 2022). In the last decades, this volcano experienced frequent crises: 1978-1980, 1988-1991, 1996, 2004-2007, 2009-2010 (Inguaggiato et al. , 2022), while the last eruption occurred in 1888-1890. For its activity, Vulcano represents the source of many potentially interconnected hazards which determine a potentially high risk. (Hazard Selva et al. , 2020). The Vulcano island has been widely investigated to understand its volcanic evolution (Gioncada et al. , 1998; Gioncada et al. , 2003; De Astis; 2013; Nicotra et al. , 2018), the dynamics affecting the plumbing and the hydrothermal systems (Alparone et al. , 2010; Cannata et al. , 2012; Alparone et al. , 2019), and the structure of the of the active “La Fossa” cone (Revil et al. , 2008; Barde-Cabusson et al. , 2009; Revil et al. , 2010). Many studies reveal a complex evolution in which the regional tectonic may play a major role. The occurrence volcanism in the southern Tyrrhenian is generally linked to large scale geodynamic processes, but, the volcanism in the southern sector of Aeolian Islands, where Volcano is located, would be also controlled by a regional-scale, lithospheric NNW-SSE trending right-lateral strike-slip fault system. Even though several evidence suggest its occurrence (Mazzuoli et al. , 1995; Ventura et al. , 1999, Mattia et al. , 2008; Barreca et al. , 2014; Cintorrino et al. , 2019), the field expression of this system is poorly constrained. Bruno and Castiello (2009) revealed some faults affecting the SW base of the active cone by means of high-resolution seismic investigations. To better understand these features and Fig. 1 - Left: relief map of Vulcano Island and the seismicity recorded in the period from January 2020 to April 2022 (Barberi et al. , 2020). Right: detail of the study area in the lower southwestern flank of La Fossa cone. The letters A and B indicate the tips of the section shown in Fig. 3.