The shallow water submarine hydrothermal field off Zannone Island (central Tyrrhenian Sea, Italy): the impact of venting activity on seafloor morphology and benthic community

The Zannone Hydrothermal Field (ZHF, 60 km2), located in the shallow-waters (3.0 Ra), similar to those recorded in other shallow water areas of the Tyrrhenian Sea (Stromboli and Panarea islands). Geochemical analyses suggest that the vented hydrothermal volatiles are probably associated with residual magma batches, chemically similar to the Pleistocene trachytes cropping out at Ponza Island, that still provide thermal energy to the submarine geothermal system. The vent activity at the ZHF seems to be controlled by the tectonic structures of the Ponza-Zannone structural high and fed by hot volatiles of magmatic origin. At present it is characterized by slow and diffuse degassing but in recent times it encompassed more explosive events. Finally, diffuse episodes of such activity have to be considered in terms of possible triggering mechanisms of shallow instability phenomena.