HR: 1340h
AN: PP13A-1476    [Abstracts]
TI: Meltwater Events in the Eastern Arctic Ocean: Relations to Eurasian Ice-dammed Lakes and Climate Forcings
AU: * Spielhagen, R F
EM: rspielhagen@ifm-geomar.de
AF: Academy of Sciences, Humanities, and Literature Mainz, c/o Leibniz-Institute for Marine Sciences IFM-GEOMAR Wischhofstr. 1-3, Kiel, 24147 Germany
AB: Analysis of foraminiferal oxygen and carbon isotope records from long sediment cores from the eastern and central Arctic Ocean reveals a number of peaks which are interpreted as evidence for strong meltwater events. Most of these events were accompanied by strong deposition of coarse ice-rafted terrestrial debris indicative of large amounts of icebergs in the area. Hgh-resolution stratigraphic models for the cores, based on a variety of independant methods, allow to identify the the ages of meltwater events within the last 200 ky. They cluster in the intervals 160-155, 140-125, 90-75, 65-60, and 55-50 ka. According to recent results from the QUEEN program (Quaternary Science Reviews, v. 23 (11-13), 2004), these times fall into intervals of extended glaciations in northern Eurasia. The ice sheets dammed large rivers in European Russia and western Siberia and led to the formation of large lakes. The "marine" ages of meltwater events in the Arctic Ocean, as determined from sediment core data, correlate well with terrestrial age estimates for the deglacial events in northern Eurasia which must have included the discharge of the meltwater lakes into the Arctic Ocean. According to amplitudes in the foraminiferal isotopic records, the strongest events occurred at the glacial terminations of marine isotope stages 6 (130 ka) and 3/4 (52 ka). In my presentation, I will give an overview of existing stratigraphic and isotopic data sets of meltwater events in the eastern and central Arctic Ocean, including their limitations. Furthermore, I will analyze possible connections of meltwater events in the Arctic to similar events in the Norwegian-Greenland Sea and to external forcings. Finally, possible evidence for a strong freshwater export from the Arctic Ocean as a trigger of the cold Younger Dryas event will be reviewed.
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 4926 Glacial
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005