Circulation of thermal waters on Pantelleria island (Sicily channel, Italy)

Recent geothermal exploration on Pantelleria, a island within the Sicily Channel, located a water-dominated geothermal field in the southern part of the island. The water-dominated reservoir, characterized by temperatures of around 250°C has recently been tapped by a deep producing well (1100m). During the survey a large number of water samples were collected from shallow water-wells and some natural manifestations. The analysis of these samples was integrated with geochemical and thermometric observations carried out in exploratory wells scattered over the island. The data collected, together with the thermodynamic and geochemical characteristics of the deep wells, suggest that the major contribution to the deep fluid comes from the sea. A ground-water circulation model is discussed. This model proposes that the thermal waters, mainly mixtures of meteoric and sea waters, flow towards the coast in the shallow part of the aquifer, and an inflow of colder sea water occurs at depth in the island