Soil diffuse degassing and thermal energy fluxes from the Southern Lakki Plain, Nisyros (Greece)

Two diffuse soil CO 2 flux surveys from the southern Lakki plain show that CO 2 is mainly released from the hydrothermal explosion craters. The correspondence between high CO 2 fluxes and elevated soil temperatures suggests that a flux of hot hydrothermal fluids ascends towards the surface. Steam mostly condenses near the surface and the heat given off is conductively transferred to the atmosphere through the soil, accompanied by a large CO 2 flux. It was calculated, that 68 t d −1 of hydrothermal CO 2 are released through the total surveyed area of ∼1.3 km². Admitting that a steam flux of 2200 t d −1 accompanies this CO 2 flux, the thermal energy released through steam condensation amounts to 58 MW.