PREPARED Present and past flow regime. On contourite drifts west of Spitsbergen

The Eurofleets-2 PREPARED cruise was conducted during June 5–15, 2014 on board the Norwegian R/V G.O. Sars to investigate the present and past oceanographic flow regime and patterns around two contourite drifts located in the eastern side of the Fram Strait (south-western margin of Spitsbergen). To achieve the main objective of the project, we plan to use a full range of time scaled measurements, from instantaneous (CTD) and seasonal (moorings) oceanographic measurements, to the recent (Box corer) and geologic (Calypso core) past record. Good weather and calm sea conditions allowed to fulfil the cruise program and to obtain a high-quality and valuable dataset including: about 2780 km of underway measurements (hullmounted ADCP and thermosalinograph); 60 CTD sites along 5 main transects; 22 sites for water sampling at different depths for biogeochemical characterization of water masses; 13 mesozooplankton samplings carried out by vertical hauls (WP2 net) and 20 by horizontal hauls (Manta net) for the study of the present biological productivity of the area; about 120 km of site survey including high-resolution multibeam map and sub-bottom profiles for the identification of current-related structures; 5 Box cores; and 2 Calypso piston cores 19.67 and 17.37 m long with an excellent sediment recovery up to 92%. In addition, 3 moorings were deployed for seasonal measurements of water currents direction and velocity, water mass temperature and salinity and to determine the annual amount of local sediment input. Preliminary onboard analyses outlined the presence of a cold-oxygenated and low salinity water mass moving in the deep northern part of the Storfjorden Trough under the effect of the Corilis force and tide configuration considerably affecting the velocity and bottom distribution of the cold water mass. The long Calypso cores contain the record of the past 20 ka with an expanded Holocene sequence (over 5 m-thick) that will allow us to obtain very-high resolution palaeoceanographic and palaeoenvironmental reconstructions in the area.