Dissolved Carbon in Groundwater versus Gas Emissions from the Soil: The Two Sides of the Same Coin

This study focuses on the interaction among deep volcanic/hydrothermal gases, groundwater and soil gases at Vulcano Island
(Aeolian Archipelago, Italy). The chemical-physical parameters of the groundwater, the total dissolved inorganic carbon (TDIC)
and the isotopic composition of the CO2 dissolved in groundwater are reported and discussed. Furthermore, a comparison
between soil gases and groundwater indicates that groundwater and soil gases show the same qualitative information, giving a
good overall picture of the main degassing zones of a volcanic system, whereas the soil gas discharge provides an evaluation of
the mass released by the deep feeding system. This approach can be a useful tool both to characterize mixing and/or interaction
processes among different sources and for a monitoring of degassing activity of a volcanic system.

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