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(Table 1) Age determination of DSDP Hole 94-607 and sediment cores V30-101 and V23-81

Authors
Publisher
PANGAEA
Publication Date
Identifiers
DOI: 10.1594/pangaea.769892
Keywords
  • 94-609
  • Age
  • 14C Calibrated
  • Age
  • Dated
  • Age
  • Dated Material
  • Age
  • Dated Standard Deviation
  • Deep Sea Drilling Project
  • Depth
  • Bottom/Max
  • Depth
  • Top/Min
  • Drilling
  • Dsdp
  • Glomar Challenger
  • Leg94
  • North Atlantic/Flank
  • Piston Corer
  • V23
  • V23-81
  • V30
  • V30-101
  • Vema

Abstract

Oxygen isotope measurements in Greenland ice demonstrate that a series of rapid warm-cold oscillations -called Dansgaard-Oeschger events- punctuated the last glaciation (Dansgard et al., 1993, doi:10.1038/364218a0). Here we present records of sea surface temperature from North Atlantic sediments spanning the past 90 kyr which contain a series of rapid temperature oscillations closely matching those in the ice-core record, confirming predictions that the ocean must bear the imprint of the Dansgaard-Oeschger events (Broecker et al., 1988, doi:10.1016/0033-5894(88)90082-8; 1990, doi:10.1029/PA005i004p00469). Moreover, we show that between 20 and 80 kyr ago, the shifts in ocean-atmosphere temperature are bundled into cooling cycles, lasting on average 10 to 15 kyr, with asymmetrical saw-tooth shapes. Each cycle culminated in an enormous discharge of icebergs into the North Atlantic (a 'Hein-rich event' (Bond et al., 1992, doi:10.1038/360245a0; Broecker et al., 1992, doi:10.1007/BF00193540), followed by an abrupt shift to a warmer climate. These cycles document a previously unrecognized link between ice sheet behaviour and ocean-atmosphere temperature changes. An important question that remains to be resolved is whether the cycles are driven by external factors, such as orbital forcing, or by inter-nal ice-sheet dynamics.

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