Ten years of soil CO₂ continuous monitoring on Mt. Etna: Exploring the relationship between processes of soil degassing and volcanic activity

Abstract

[1] The measurement of soil CO 2 flux variations is a wellÀestablished practice in many volcanic areas around the world. Until recently, however, most of these were made using direct sampling methods. These days, a variety of automatic devices providing real-time data now make the continuous monitoring of volcanic areas possible. A network of automatic geochemical monitoring stations (EtnaGas network) was developed by INGV Palermo and installed at various sites on the flanks of Mt. Etna. Here, we present a large set of soil CO 2 flux data recorded by the network, dating back 10 years, a period in which several noteworthy eruptive phenomena occurred. Our statistical analysis strongly suggests that anomalous measurements of soil CO 2 flux are attributable to volcanic origin and in almost all cases precede volcanic activity. Here, we present the actual data series recorded by EtnaGAS and an interpretative model of the expected behavior of soil CO 2 flux (in terms of increase-decrease cycles), which corresponded well with the volcanic activity during this period. Through the use of a comparative approach, incorporating both volcanological and geochemical data, the global soil CO 2 flux trends are put into a coherent framework, highlighting close links between the time flux variations and volcanic activities. These insights, made possible from 10 years of uninterrupted data, confirm the importance of continuous monitoring of volcanic soil degassing, and may contribute in the forecasting of imminent eruptive activity or the temporal evolution of an in-progress eruption, therefore facilitating Civil Defense planning in volcanic areas under high-hazard conditions.

Pressurization and depressurization phases inside the plumbing system of Mount Etna volcano: Evidence from a multiparametric approach

“…In this method, three steps are considered: first, each time series from all the stations is filtered for the meteorological parameters and/or seasonal variations; second, in order to compare the amplitude of the CO 2 flux variation from different stations, each soil CO 2 flux series is normalized within the range of 0–1; and finally, all the time series from each station are added together and the final sum is normalized again within the interval 0–1 (more details on the method in Liuzzo et al . []).…”

“…CO 2 flux measurements are carried out by the dynamic method [Gurrieri and Valenza, 1988;Gurrieri et al, 2008, and reference therein], in which the CO 2 content in a mixture of air and soil gas is obtained by means of a probe inserted into the soil at a depth of 50 cm. In accordance with the method proposed in Liuzzo et al [2013], we consider here the same data processing approach to obtain a unified CO 2 flux signal from all the monitoring stations of the network. In this method, three steps are considered: first, each time series from all the stations is filtered for the meteorological parameters and/or seasonal variations; second, in order to compare the amplitude of the CO 2 flux variation from different stations, each soil CO 2 flux series is normalized within the range of 0-1; and finally, all the time series from each station are added together and the final sum is normalized again within the interval 0-1 (more details on the method in Liuzzo et al [2013]).…”

A comprehensive interpretative model of slow slip events on Mt. Etna's eastern flank

“…The monitoring station is part of the EtnaGAS network and monitored parameters are: CO 2 soil flux and atmospheric parameter (T, P, Rh, rain, wind speed and wind direction; Liuzzo et al . [] and Gurrieri et al ., []. Data were collected with hourly frequency.…”

“…This site is located some 3 km east of site ZAF06 along the same structural lines, and it is characterized by higher emissions of CO 2 associated with other magmatic gases [Giammanco et al, 1995;Giammanco et al, 1998;Giammanco and Bonfanti, 2009]. The monitoring station is part of the EtnaGAS network and monitored parameters are: CO 2 soil flux and atmospheric parameter (T, P, Rh, rain, wind speed and wind direction; Liuzzo et al [2013] and Gurrieri et al, [2008]. Data were collected with hourly frequency.…”

Soil CO2 Degassing Path along Volcano-Tectonic Structures in the Pico-Faial-São Jorge Islands (Azores Archipelago, Portugal)

“…CO 2 has been widely used for volcanic monitoring due to its low solubility in silicate melts, being consequently one of the first gases released to the surface in case of replenishment of a magma chamber (e.g., Hernández et al, 2001;Giammanco et al, 2006;Aiuppa et al, 2010;Liuzzo et al, 2013;de Moor et al, 2016). Carbon dioxide is also an inert asphyxiant gas if present in high concentrations in the air, and above 10 vol.% can be lethal (Blong, 1984;Weinstein and Cook, 2005).…”