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Paleoceanographic evolution of the SW Svalbard margin (76°N) since 20,000 C yr BP |
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| Authors: | Tine L Rasmussen Erik Thomsen Simon Jessen Nalân Koç |
| Institution: | a Department of Geology, University of Tromsø, Dramsveien 201, N-9037 Tromsø, Norway b Department of Earth Sciences, University of Aarhus, DK-8000 Århus C, Denmark c The University Centre in Svalbard (UNIS), PO Box 156, N-9171 Longyearbyen, Norway d Norwegian Geotechnical Institute (NGI), PO Box 3930, Ullevaal Stadion, N-0806 Oslo, Norway e Norwegian Polar Institute, Polar Environmental Centre, N-9296 Tromsø, Norway |
| Abstract: | Two cores from the southwestern shelf and slope of Storfjorden, Svalbard, taken at 389 m and 1485 m water depth have been analyzed for benthic and planktic foraminifera, oxygen isotopes, and ice-rafted debris. The results show that over the last 20,000 yr, Atlantic water has been continuously present on the southwestern Svalbard shelf. However, from 15,000 to 10,000 14C yr BP, comprising the Heinrich event H1 interval, the Bølling-Allerød interstades and the Younger Dryas stade, it flowed as a subsurface water mass below a layer of polar surface water. In the benthic environment, the shift to interglacial conditions occurred at 10,000 14C yr BP. Due to the presence of a thin upper layer of polar water, surface conditions remained cold until ca. 9000 14C yr BP, when the warm Atlantic water finally appeared at the surface. Neither extensive sea ice cover nor large inputs of meltwater stopped the inflow of Atlantic water. Its warm core was merely submerged below the cold polar surface water. |
| Keywords: | Paleoceanography Atlantic water polar water Svalbard shelf and slope Foraminifera Oxygen isotopes IRD |
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