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Advection of Atlantic Water to the western and northern Svalbard shelf since 17,500 cal yr BP

Koç, Nalan 1 ; Klitgaard Kristensen, Dorthe 2 ; Rasmussen, Tine L 3 ; Slubowska-Woldengen, Marta 4 ; Nilsen, Frank 5 ; Solheim, Anders 6

1 Norwegian Polar Institute, Polar Environmental Centre, N-9296 Tromsø, Norway
2 Norwegian Polar Institute, Polar Environmental Centre, N-9296 Tromsø, Norway
3 Department of Geology, University of Tromsø, Dramsveien 201, N-9037 Tromsø, Norway
4 Norwegian Petroleum Directorate, Verkstedveien 1, 9488 Harstad, Norway
5 The University Centre in Svalbard, PO Box 156, N-9
6 International Centre for Geohazards, Norwegian Geotechnical Institute, Po Box 3930, Ullevål Stadion, N-0806 Oslo, Norway

The Svalbard archipelago is located in the high Arctic (76-80° N) within the northernmost reach of the warmer West Spitsbergen Current, which is the continuation of the North Atlantic Current. This current is a major regulator of the environment in the Arctic and changes in sea-ice distribution in the Arctic Ocean have been related to variability in temperature and flux of this current (Aagaard and Carmack 1989; Rudels et al., 1994). Detecting the temporal and spatial variability of this current is therefore essential for understanding past environmental and climate changes in the Arctic. Due to the proximity of the Svalbard area to the West Spitsbergen Current it is ideal for monitoring the past history of the inflow of Atlantic water to the Arctic Ocean. The changes in flow and character of the warm Atlantic Water through the last 17,500 cal yr are reconstructed from the distribution of benthic foraminifera species, planktonic and benthic foraminifera abundances, stable oxygen isotopes and lithology in two cores from the western and northern shelf of Svalbard. The results show almost continuous presence of Atlantic Water at the shelf areas since >14,500 cal yr BP. The Bølling and Allerød intervals stand out as periods of highest bottom waters temperatures. The strong inflow of saline, but chilled Atlantic Water during the early Holocene was followed by cooling and freshening of the bottom waters during the mid- and late Holocene. The two records reveal synchronous oceanographic changes that are closely tied to changes in the flow of Atlantic Water recorded further south in the Nordic seas. The early Holocene warming was not just an effect of higher solar insolation, but was also due to increased heat flux from the stronger Atlantic Water inflow driven by wind force and/or thermohaline circulation.

Aagaard, K., and Carmack, E.C., 1989. The role of sea ice and other freshwater in the Arctic circulation. Journal of Geophysical Research, 94, 14485-14498.

Rudels, B., Jones, E.P., Anderson, L.G. and Kattner, G., 1994. On the intermediate depth waters of the Arctic Ocean. In: O.M. Johannessen, R.D. Muench, J.E. Overland (eds.), The Polar Oceans and their role in shaping the global environment, Geophysical Monograph 85, 33-46