Continuous Monitoring of Dissolved CO2 and H2S: Technical Application in the Submarine Hydrothermal System of Panarea, Italy

Additionally to flow rate measurements of fluid discharges in submarine hydrothermal systems, in-situ-measurements of concentrations of dissolved gases like CO2 and H2S can provide important information about the state of a hydrothermal system. Sampling and following laboratory methods are costly and not sufficient with respect to sampling intervals. Commercial sensors to monitor dissolved CO2 and H2S in seawater are so far unavailable. Therefore a sensor device based on commercially available sensors for gas monitoring was designed, constructed, and tested. The sensor array was tested in the submarine hydrothermal system of Panarea, Aeolian Islands, Italy. The first application provided important insight into variations of CO2 and H2S concentrations. Besides influences by earth tides, also additional fluctuations can be monitored by long term records.