HR: 0800h
AN: PP41B-0638    [Abstracts]
TI: The Climatic Development of MIS 11 at High Northern Latitudes
AU: * Helmke, J P
EM: jhelmke@ifm-geomar.de
AF: Leibniz Institute of Marine Sciences (IFM-GEOMAR), Wischhofstr. 1-3, Kiel, 24148 Germany
AU: Bauch, H A
EM: hbauch@ifm-geomar.de
AF: Leibniz Institute of Marine Sciences (IFM-GEOMAR), Wischhofstr. 1-3, Kiel, 24148 Germany
AU: Bauch, H A
EM: hbauch@ifm-geomar.de
AF: Academy of Sciences, Humanities and Literature, Geschwister-Scholl-Str. 2 , Mainz, 55131 Germany
AB: Based on a number of proxy records from various climate archives it has often been claimed that among the Pleistocene interglacial intervals Marine Isotope Stage (MIS) 11 was an exceptionally long warm climatic period. However, several studies of late Pleistocene full interglacial intervals in the polar North Atlantic region, i.e., MIS 11, 5e, and 1, indicate comparatively reduced advection of heat and moisture to the high northern latitudes within MIS 11. This may suggest regional differences of the climate conditions during MIS 11 and demonstrates the need to further specify the development of the oceanographic and climatic conditions of this interglacial period. Here we present a set of high-resolution sedimentological, geochemical, and micropaleontological records of MIS 11 from two adjacent deep-sea sediment cores (PS1243 and MD992277, both 69°N and 6°W) from the central polar North Atlantic. From our results it can be proposed that the glacial Termination from MIS 12 into MIS 11 was very long and pronounced showing repeated pulses of massive ice-rafted debris (IRD) input at the study region. As soon as IRD deposition ceased, full interglacial conditions rapidly developed. A marked increase in carbonate content and also in the amount of subpolar planktic foraminifers can be observed, parallel to a rise of both benthic and planktic oxygen isotope values to a level typical for the late Pleistocene interglaciations of the study area. Peak warm conditions are only established after the maximum in planktic isotopes had occurred. For this interval all parameters point to a substantial influence of Atlantic surface waters at the study region. This full interglacial period of MIS 11 lasted in the northern North Atlantic region for about 10,000 years, thus questioning the idea of an extremely warm and long lasting MIS 11 at least on a global scale.
DE: 4936 Interglacial
DE: 4944 Micropaleontology (0459, 3030)
DE: 4954 Sea surface temperature
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005