Glider measurements around the Vercelli Seamount (Tyrrhenian Sea) in May 2009

The Vercelli Seamount is an undersea topographic feature of the northern Tyrrhenian Sea which rises from around 2000 m depth to almost the surface (55 m depth). In late spring 2009 the interdisciplinary experiment “Tyrrhenian Seamounts Ecosystems: an integrated study” was conducted around the seamount to investigate its infl uence on the hydrodynamics and the biogeochemical conditions of the area. As part of this integrated study a Slocum glider was operated around the seamount from 23 to 30 May, 2009 to sample the physical and biogeochemical characteristics of the water column from the sea surface down to 190 m depth. The observations revealed little infl uence of the seamount of the near-surface circulation and water mass characteristics. They showed, however, slanted sub-mesoscale structures below the thermocline in the southern area of the seamount. These features evidenced