A Late Glacial–Early Holocene multiproxy record from the eastern Fram Strait, Polar North Atlantic

Aagaard-Sørensen, Steffen, Husum, Katrine, Werner, Kirstin, Spielhagen, Robert F., Hald, Morten and Marchitto, Tom M. (2014) A Late Glacial–Early Holocene multiproxy record from the eastern Fram Strait, Polar North Atlantic Marine Geology, 355 . pp. 15-26. DOI 10.1016/j.margeo.2014.05.009.

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Abstract

The paleoceanographic development of the eastern Fram Strait during the transition from the cold Late Glacial and into the warm Early Holocene was elucidated via a multiproxy study of a marine sediment record retrieved at the western Svalbard slope. The multiproxy study includes analyses of planktic foraminiferal fauna, bulk sediment grain size and CaCO3 content in addition to Mg/Ca ratios and stable isotopes (delta C-13 and delta O-18) measured on the planktic foraminifer Neogloboquadrina pachyderma. Furthermore paleosubsurface water temperatures were reconstructed via Mg/Ca ratios (sSST(Mg/Ca)) and transfer functions (sSST(Transfer)) enabling comparison between the two proxies within a single record. The age model was constrained by four accelerator mass spectrometry (AMS) C-14 dates.

From 14,000 to 10,300 cal yr B.P. N. pachyderma dominated the planktic fauna and cold polar sea surface conditions existed. The period was characterized by extensive sea ice cover, iceberg transport and low subsea surface temperatures (sSST(Transfer) similar to 2.1 degrees C; sSST(Mg/Ca) similar to 3.5 degrees C) resulting in restricted primary production. Atlantic Water inflow was reduced compared to the present-day and likely existed as a subsurface current. At ca. 10,300 cal yr B.P. Atlantic Water inflow increased and the Arctic Front retreated north-westward resulting in increased primary productivity, higher foraminiferal fluxes and a reduction in sea ice cover and iceberg transport. The fauna rapidly became dominated by the subpolar planktic foraminifer Turborotalita quinqueloba and summer sSST(Transfer) increased by similar to 3.5 degrees C. Concurrently, the sSST(Mg/Ca) recorded by N. pachyderma rose only similar to 0.5 degrees C. From ca. 10,300 to 8600 cal yr B.F. the average sSST(Mg/Ca) and sSST(Transfer) were similar to 4.0 degrees C and similar to 55 degrees C, respectively. The relatively modest change in sSST(Mg/Ca) compared to sSST(Transfer) can probably be tied to a change of the main habitat depth and/or shift in the calcification season for N. pachyderma during this period.

Document Type: Article
Additional Information: WOS:000341339600002
Keywords: Planktic foraminifera; sub-sea surface temperature reconstruction; trace elements; transfer functions; stable isotopes; Late Glacial/Holocene transition; Fram Strait; Polar North Atlantic
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-P-OZ Paleo-Oceanography
Refereed: Yes
DOI etc.: 10.1016/j.margeo.2014.05.009
ISSN: 0025-3227
Projects: INTERDYNAMIK, Laptev Sea System, Transdrift
Expeditions/Models:
Date Deposited: 10 Oct 2014 12:04
Last Modified: 23 Feb 2015 11:19
URI: http://eprints.uni-kiel.de/id/eprint/25760

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