Dissolved CO2 in natural waters: development of an automated monitoring system and first application to Stromboli volcano (Italy)

Abstract

The study of geochemical parameters applied to natural systems has provided improved knowledge of geochemical mechanisms of gas/rock dissolution in natural waters that are linked to gas–water and/or water– rock interaction processes. Here we present the results of our studies focused on the development of an automated monitoring system for measuring the amount of dissolved CO2 in natural waters. The system is based on the principle of a dynamic equilibrium between water and the air as the host gas. The PCO2 measurements were carried out every four hours, and the equilibration time was around 20 minutes. Moreover, application to the thermal aquifer of Stromboli volcano during the 2009-2010 period is shown and analyzed. The data highlight a clear correlation between the changes in the PCO2 in the thermal aquifer and the changes in volcanic activity.