Experimentation of an automatic continuous monitoring station in a thermal well of Stromboli volcanic island (Italy).

Chemical-physical modifications of groundwater in active volcanic areas provide important insights on magma ascent leading to volcanic eruptions. To fully exploit the great potential of fluid geochemistry, the traditional discontinuous sampling with subsequent laboratory analysis should be replaced by automatic continuous data recording stations. Such a station, that measures every second pH, Eh, conductivity, T and dissolved CO2 and CH4 contents, has been experimentally tested in a shallow thermal well of Stromboli for the first time. A strong explosive paroxysm occurred during the test. Before the event variations in T, pH and dissolved CO2 indicative of an increasing gas influx were recorded by the station.