HR: 1340h
AN: PP13A-0593    [Abstracts]
TI: A New Climato-Stratigraphic Scheme of MIS5e for the Northern High-Latitude
AU: * Bauch, H A
EM: hbauch@ifm-geomar.de
AF: Mainz Academy c/o IFM-GEOMAR, Wischhofstrasse 1-4, Kiel, 24148 Germany
AU: Kandiano, E S
EM: ekandiano@ifm-geomar.de
AF: IFM-GEOMAR, Wischhofstrasse 1-4, Kiel, 24148 Germany
AU: Erlenkeuser, H
EM: HErlenkeuser@leibniz.uni-kiel.de
AF: Leibniz Laboratory Kiel University, Max-Eyth-Strasse 11, Kiel, 24098 Germany
AU: Johnsen, S J
EM: sigfus@gfy.ku.dk
AF: Niels Bohr Institute Copenhagen University, Blegdamsvej 17, Copenhagen, 2100 Denmark
AB: Multiproxy analyses of sediment cores from the Nordic seas allow to define last interglacial climate intervals into: (1) the deglaciation of MIS6 (T2); (2) the ensuing warm peak interglacial (PI) period with a water mass configuration similar to MIS1; (3) the time of climate deterioration with increasing ice volume and surface water cooling. T2 is characterized by a recurring appearance of the low-latitude planktic foraminifera Beella megastoma which was associated with cold surface waters, meltwater input and reduced deep-going vertical convection. Across the Nordic seas, up to three such events are identified between 129 and 124 ka. At the end of T2 B. megastoma vanished from the Nordic seas together with icebergs while increased subpolar foraminiferal abundance verify the existence of modern-like thermohaline circulation (THC) between 124 and 118 ka. However, surface water temperatures began already to decline notably before iceberg activity recurred (2-3 kyrs earlier), indicating unstable climate conditions during the interglacial-glacial transition. Despite climate boundary conditions were similar in MIS1 and MIS5e, major discrepancies remain. These are found for the terminations as well as for the PIs. Although O-isotopes in planktic foraminifers and Greenland ice infer warmer conditions in MIS5e, other ocean proxies from the Nordic seas support a much more vigorous THC for MIS1, altogether emphasizing the variable modes of an interglacial ocean-atmosphere circulation regime at high latitudes.
DE: 4870 Stable isotopes
DE: 3344 Paleoclimatology
DE: 4267 Paleoceanography
DE: 1724 Ocean sciences
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting