Integrated Oceanographic Research of Discovery Gap (Eastern North Atlantic) during the Cruise 43 of the R/V Akademik Nikolaj Strakhov

Abstract

During cruise 43 of the R/V Akademik Nikolaj Strakhov (September 21–October 9, 2019), new data were obtained on the bottom relief, sedimentation, and hydrological regime of the Discovery Gap (eastern North Atlantic). It was shown that the upper limit of the Antarctic Bottom Water in the study area follows the 2.05°C isotherm and 34.91 PSU isohaline at depths of 4400–4700 m. A digital elevation model of the Discovery Gap relief was obtained. Three acoustic facies have been identified, which characterize dense bottom sediments and low sedimentation rates. Sediment cores ANS-43003, ANS-43004, and ANS-43006 are represented by light brown silty clays with foraminiferal sands and bioturbation. Strong dissolution of foraminifera was found in core ANS-43006, which indicates the formation of sediments below the calcium carbonate compensation depth.