Cyclic Behavior in the Fumaroles Output Detected by Direct Measurement of Temperature of the Ground

Abstract

On the Island of Vulcano (Aeolian Archipelago, Italy) the temperatures of fumarole emissions, have ranged from about 700 °C to the boiling point. Since the end of the last eruption (1890 A.D.), many periods of increased heating of hydrothermal systems, underlying the La Fossa area have been identified, but an eruptive condition has not yet been reached. The time variation of the high temperature fumaroles has been tracked by the network of sensors located at a few discrete sites on the summit area of La Fossa cone. The same continuous monitoring network has been working for more than 30 years. The time series shows that a natural cyclic modulation has repeated after almost 20 years, and its periodicity yet has to be discussed and interpreted. The statistical approach and the spectral analysis could provide an objective evaluation to reveal the timing, intensity, and general significance of the thermodynamic perturbations that occurred in the hydrothermal circuits of La Fossa caldera, during the study period. The continuous monitoring data series avoid unrealistic interpolations and allow promptly recognizing changes, which perturb the hydrothermal circuits, highlighting—possibly in near real time—the transient phases of energy release from the different sources (hydrologic/magmatic).

The Extensive Parameters as a Tool to Monitoring the Volcanic Activity: The Case Study of Vulcano Island (Italy)

“…Such a geochemical tool has been successfully applied to Vulcano Island, the southernmost of the islands of the Aeolian archipelago, characterized by solfataric activity in the last few centuries after the last eruption occurred in 1888-1890 [2][3][4][5][6][7][8][9][10][11][12]. The solfataric activity is mainly concentrated in the top part of the island in the crater of the Fossa and the Bay of Levante (Figure 1).…”

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

“…Vulcano island, in the Aeolian archipelago (south Mediterranean Sea), is a close conduit volcano that erupted for the last time in 1888–1890. Since then, it has been characterized by a sustained degassing activity, periodically interrupted by degassing crises, as in 1978–1980 18 , 1988–1991 19 – 23 , 1996 24 , 2004–2007 25 – 27 , 2009–2010 9 – 28 , and the last one, still ongoing at the time of writing, started in the second half of 2021 13 , 29 – 32 . These crises have been characterized by increasing in volatiles and energy output which suggest a resuming of volcanic activity.…”