Susanne Juul Lassen

Northeast Atlantic sea surface circulation during the past 30‐10 14C kyr B.P.

A study was made of three cores from the Faeroe-Shetland gateway, based on planktonic foraminifera, oxygen isotopes, accelerator mass spectrometry 14C dates, magnetic susceptibility, and counts of ice rafted debris (IRD). The data, covering the period 30–10 ka, show that during the Last Glacial Maximum the Arctic Front occupied a position close to the Faeroes, allowing a persisting inflow of Atlantic surface water into the Faeroe-Shetland Channel. The oceanographic environment during deposition of two IRD layers is influenced by Atlantic surface water masses during the lower IRD layer, with transport of icebergs from N-NW. Polar surface water conditions prevailed only during deposition of the upper IRD layer. There is no indication of surface meltwater influence in the region during the deglaciation, but there is a persistent influence of Atlantic surface water masses in the region. Thus we conclude that during almost the entire period (30-10 ka) the Faeroe-Shetland Channel was a gateway for transport of Atlantic surface water toward the Norwegian Sea.

Intermediate water signal leads surface water response during Northeast Atlantic deglaciation

Abstract Multi-proxy records of the high resolution core ENAM94-09 from the Faeroe region, NE Atlantic, were used to reconstruct paleoceanographic conditions at intermediate water depth during the Last Glacial Maximum (LGM, 19.3–16.7 ka BP) and the initial deglaciation period (16.7–>14 ka BP). The methods comprise micropaleontological and geochemical analyses as well as measurements of stable isotopes and AMS 14 C dating for stratigraphic control. Owing to exceptionally high sedimentation rates of 90 cm/ka during the LGM and the initial deglaciation, it has been possible to resolve that the intermediate water masses in the Faeroe area lead the surface water deglaciation signal by 1.6 ka. The time span of this lead corresponds to the “Southern Hemisphere Lead” recently reported from the Atlantic sector of the Southern Ocean [Paleoceanography, 14 (1999) 135]. It is suggested that an interhemispheric teleconnection at intermediate water depth played a crucial role during deglaciation and in the final ice surge events around the northern North Atlantic.