RETRACTED ARTICLE: Late Quaternary stable isotope record and meltwater discharge anomaly events to the south of the Anta
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Sung Ho Bae Æ Ho Il Yoon Æ Byong-Kwon Park Yeadong Kim
Late Quaternary stable isotope record and meltwater discharge anomaly events to the south of the Antarctic Polar Front, Drake Passage Received: 6 December 2002 / Accepted: 27 June 2003 / Published online: 6 September 2003 Springer-Verlag 2003
Abstract Marine isotope stages (MISs) 1 to 5 were identified in the planktonic d18O record in sediment core DP00-02 just south of the Antarctic Polar Front in the Drake Passage, Antarctica. The oxygen isotope record, based on Neogloboquadrina pachyderma sinistral, is correlated with the contemporaneous global d18O stratigraphy. Marked deviations from the global climate curve suggest a local/regional overprint, particularly during MIS 3 which is considered a colder time period in the ocean record than MIS 1 and MIS 5 during the last interglacial. The comparison shows that negative d18O shifts in core DP00-02 during MIS 3 are larger than mean global changes which show a shift equal to or smaller than 0.5&. The isotope shift, exceeding the glacial-interglacial ice volume effect, probably resulted from changes in the isotope composition of seawater, which is linearly related to decreases in salinity rather than to increases in seasurface temperature. Increased ice-rafted debris (IRD) content during this interval indicates a strong influx of IRD from melting ice shelves and icebergs, which may be related to upwelling of warmer circumpolar deep water.
Introduction The Antarctic marine sedimentary environment appears to be an important recorder of paleoclimatic variations. Present and past climatic changes influence the ice-shelf edge, sea-ice distribution, oceanic circulation patterns and, as a consequence, the main biogeochemical
S. H. Bae (&) Æ H. I. Yoon Æ B.-K. Park Æ Y. Kim Polar Sciences Laboratory, Korea Ocean Research and Development Institute, P.O. Box 29, 425-600 Ansan, Seoul, Korea E-mail: [email protected] Tel.: +82-31-4006401 Fax: +82-31-4085825
processes in the region, including biological productivity and sedimentation. In particular, the Antarctic Polar Front (APF), which is located between the ice-covered polar waters and the relatively warm Subantarctic waters, renders the Antarctic Ocean a key region for understanding changes in paleoclimate and paleoceanography during the Neogene glacial-interglacial cycles (Morley 1989; Grobe and Mackensen 1992; Howard and Prell 1992, 1994). The shifting of the APF, i.e., the southward and northward movement of the polar water, is strongly influenced by glacial-interglacial climate change, and its record is well imprinted on the sediments in the region. Several studies have been carried out around the APF in order to identify environmental and paleoclimatic changes on the basis of planktonic foraminiferal faunas and their stable isotope records in these marine sediments. In the north of the APF, results of detailed studies on changes in stable isotope composition, in relation to variations in oceanic circulation patterns, sea-surface temperature, and/or meltwater discharge d
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