The volcanic activity changes occurred in the 2021–2022 at Vulcano island (Italy), inferred by the abrupt variations of soil CO2 output

Abstract

The active cone of La Fossa is a close conduit volcano characterized by solphataric activity, manifested by discharging fluids through fumaroles and soil degassing. Since 1978 several degassing crises have been observed and interpreted as early signals of volcanic unrests. Recently, from June 2021 to May 2022, we measured the changes in soils CO2 release to evaluating the level and duration of the actual exhaling crises. The CO2 output has been evaluated by surveys carried out in anomalously degassing areas, located both in the La Fossa cone summit area and in other peripheral zones, coupled to near-real time monitoring data acquired by three automated stations. The strong and deep input of volatiles released from an underlying magma batch modified the chemical composition of the shallow plumbing system, bringing the system to a higher level of CO2 total pressure. This work highlights that a geochemical networks of stations, located at some distance from the fumaroles release and/or from eruptive conduits, is useful and can be applied to characterizing and monitoring any other active volcanic system. This type of studies can be useful to contribute to forecast the next evolution of the studied systems.

Multi‐Temporal InSAR, GNSS and Seismic Measurements Reveal the Origin of the 2021 Vulcano Island (Italy) Unrest

“…The overall results presented here indicate that the investigated unrest phase (September‐December 2021), that is, inflation and seismicity, together with anomalies in gasses emissions (Aiuppa et al., 2022; Federico et al., 2023; Inguaggiato et al., 2022, 2023), is compatible with the expansion of the hydrothermal system located within the La Fossa Caldera. Thermal anomalies also show a similar trend, with a peak again in October 2021 (Coppola et al., 2022; Corradino et al., 2023; Pailot‐Bonnétat et al., 2023).…”

“…Thermal anomalies also show a similar trend, with a peak again in October 2021 (Coppola et al., 2022; Corradino et al., 2023; Pailot‐Bonnétat et al., 2023). While the thermal anomalies have been interpreted as an increase in temperatures of the fumarolic field present in the crater area of the La Fossa cone, the geochemical anomalies are interpreted as an increase in the parameters of the hydrothermal system which in turn is enriched in a strong and deep input of fluids released from an underlying magma batch (Aiuppa et al., 2022; Inguaggiato et al., 2022).…”

Quantification of the Volcanic Carbon Dioxide in the Air of Vulcano Porto by Stable Isotope Surveys

“…In 2021, Vulcano experienced a significant increase in volcanic outgassing (Aiuppa et al, 2022;Di Martino et al, 2022;Federico et al, 2023;Inguaggiato et al, 2022). Although Vulcano has not yet produced a volcanic eruption, the Italian civil protection authorities (DPC) prohibited access to some zones of the island where high φCO 2 caused a sharp increase in the gas hazard.…”

“…An increase in CO 2 production caused either by the influx of tourists to the island of Vulcano (i.e., during the summer months) or by the combustion of hydrocarbons to heat houses may be responsible for these fluctuations. Notable changes occurred in 2021, when the less 13 C‐depleted signature of CO 2 in the air clearly shows that the increase in CO 2 concentration correlates with a resumption of volcanic degassing (Aiuppa et al., 2022; Di Martino et al., 2022; Federico et al., 2023; Inguaggiato et al., 2022). During this period, there was a remarkable increase in CO 2 concentration due to plume dispersion and φCO 2 .…”

Anatomy of thermal unrest at a hydrothermal system: Case study of the 2021-2022 crisis at Vulcano

“…SO 2 ux began increasing in April 2021, exceeding the baseline sporadically in June, and persistently from August 2021 onwards (Inguaggiato et al 2022b). VLP events increased from zero to several hundred events per day during September (Gangemi et al 2022), at which time increasing trends in all thermal and CO 2 metrics also picked up (Inguaggiato et al 2022b). The geochemistry of the gas sampled from fumaroles indicates an increasingly dominant magmatic signature from July The start of the seismic events in early September indicates the breaking of the system seal, when uids could ascend to the surface easier, thus explaining the increase of all signals from this point onwards.…”