Holocene variability of surface and subsurface Atlantic Water inflow on the West Spitsbergen continental margin
The Atlantic Water inflow through Eastern Fram Strait - a major pathway of warm and saline water to the Arctic Ocean – plays an essential role for the Arctic Ocean heat budget (Schauer et al., 2004). Atlantic Water (AW) has been continuously present since ca 20,000 years in the Eastern Fram Strait (...
| Main Authors: | , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2011
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| Online Access: | https://oceanrep.geomar.de/id/eprint/11910/ http://www.geogr.msu.ru/structure/labs/notl/nauchd/downloads/Abstracts_2011_APEX_Longyearbyen.pdf |
| Summary: | The Atlantic Water inflow through Eastern Fram Strait - a major pathway of warm and saline water to the Arctic Ocean – plays an essential role for the Arctic Ocean heat budget (Schauer et al., 2004). Atlantic Water (AW) has been continuously present since ca 20,000 years in the Eastern Fram Strait (Rasmussen et al., 2007). However, the conditions of the AW inflow through the Fram Strait have varied much throughout the Holocene. From two sediment cores from the West Spitsbergen continental margin we present multiproxy evidence of variations of the Atlantic Water inflow and the position of the sea ice margin during the past ca 10,000 cal kyr BP. Maximum occurrence of the subpolar planktic foraminifer species T. quinqueloba suggests warmest temperatures of the Atlantic Water - bearing West Spitsbergen Current during the early part of the Holocene (10 to 8 cal ka BP). However, low planktic d13C values indicate limited ventilation of the AW layer that most likely submerged beneath a relatively thick surface layer of sea ice and lower salinity. A second warming pulse between 5 and 6 ka was accompanied by higher planktic d13C values pointing to the AW layer appearing at the surface. In the second half of the Holocene, increased IRD contents indicate a neoglacial trend found in many records of the North Atlantic realm (e.g. Koç and Jansen, 2002). Despite of the decreasing solar insolation planktic foraminiferal assemblages suggest a return of slightly strengthened Atlantic Water advection around 3 to 2 ka and a strong warming event in the present, anthropogenically influenced period. |
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