Paleoceanographic development during the last deglaciation and Holocene, over the Bear Island slide scar, SW Barents Sea

Abstract

The investigated sediment core HH13-243 GC is located under the present flow of the warm and saline Atlantic Water (AW), but close to, glaciated continental margins. The core site is situated in an area that is sensitive to changes and reflects the paleoceanography of the northernmost Norwegian Sea and the Western Barents Sea. We investigated the changes in inflow of Atlantic water and the subsequent paleoceanographic development over the Bear Island slide scar, which is situated on the southern part of the Bear Island Through Mouth Fan. The results are based on planktic and benthic foraminiferal assemblages, stable isotopes and concentration and flux of IRD. An age model was established based on five AMS 14C dates and the core were divided into six time intervals. The results indicate almost continuous presence of Atlantic water at the slope since 15 500 cal. yr. BP. Heinrich event 1was characterised by warmer bottom water conditions than today and may reflect a 4-2 degree temperature change over a short time interval. Bølling- Allerød interstadial (15 400- 12 500 cal. yr. BP) was characterised by inflow of chilled Atlantic water with extensive sea ice cover. The transition from the Younger Dryas to the Early Holocene indicate an abrupt change in the planktic foraminiferal fauna, where warm water species replace the polar water species, and the Atlantic water dominate at the sea surface. The rest of the Holocene is characterized by mixing of Atlantic and Arctic water.