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abstracts
Variability of Late Holocene Atlantic Water advection on the West Spitsbergen continental margin
Kirstin Werner, Robert F. Spielhagen, Katarzyna Zamelczyk, Katrine Husum, Morten Hald
Presently the Fram Strait and the Arctic Ocean are responding very rapidly to global warming. The Fram Strait is the only deep-water passage for Atlantic Water masses to enter the Arctic Ocean. The western part of the Fram Strait is today perennially ice-covered, while relatively warm Atlantic waters enter the Arctic Ocean through the eastern part of Fram Strait keeping it ice-free all year. Accumulation of relatively thick Holocene sedimentary sequences is attributed to sediment transport at certain water depths along the margin and deposition of fine-grained sediments at sites of “lee positions“ with diminished flow velocities. Sediment cores from the West Spitsbergen continental margin with high resolution of the late Holocene have been studied in order to establish multiproxy data sets with a centennial to decadal time resolution during the last 2000 cal. yr BP. Isotopic, micropaleontological, sedimentological, and geochemical proxies are used to reconstruct variations of Atlantic Water advection to the Arctic, the sea ice extent, and the structure of the water column during the late Holocene. The records of foraminiferal oxygen and carbon isotopes, planktic foraminifer associations, and the amount of ice rafted debris clearly reveal climatically warmer and colder periods such as the Roman Climatic Optimum, the Medieval Warm Period, and the Little Ice Age. In addition, the data reveal a significant variation of Atlantic heat advection to the Arctic during the last 2000 years, including a strong warming event in the present, anthropogenically influenced period.
Kirstin Werner, Paleoceanography, Leibniz Institute for Marine Sciences IFM-GEOMAR,Wischhofstr. 1-3, 24148 Kiel, Germany, kwerner@ifm-geomar.de
Robert F. Spielhagen, IFM-GEOMAR c/o Academy of Sciences, Humanities, and Literature Mainz, Paleoceanography, Germany
Katarzyna Zamelczyk, University of Tromsø, Department of Geology, Norway
Katrine Husum, University of Tromsø, Department of Geology, Norway
Morten Hald, University of Tromsø, Department of Geology, Norway
Session: F2: Regional Climate Dynamics
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