Conductivity and Temperature as indicators of hydrothermal activity: A comparison of two submarine volcanoes (Greece)

The presence of active hydrothermal vent fields near residential areas and their possible link to volcanic activity pose a potential natural hazard to the environment, to society, and to the economy. Despite the importance of risk assessment and mitigation, the monitoring of volcanic activity is hindered by the remoteness and extreme conditions of underwater volcanoes. By developing a mathematical model for geological and physical processes in these environments we shed light on the underlying dynamics of chemical products emitted from the vents and point to the underlying mechanisms that govern potentially hazardous, underwater volcanic environments. Santorini and Nisyros both belong to the Hellenic Volcanic Arc but appear to have different underlying mechanisms. The Generalized Moments Method (GMM) was applied to data gathered from the Northern Caldera of Santorini and the Nisyros caldera, Avyssos, for the purpose of this work, where we focus on the high-frequency recorded CTD data (Conductivity, Temperature, Depth) in the water column over the hydrothermal vents. The data from Santorini were collected in 2017 using an Autonomous Underwater Vehicle (AUV) during the POS510 mission led by GEOMAR, while the data from Nisyros were gathered with the help of a Remotely Operated Vehicle (ROV) in 2010, during the Nautilus expedition.