Variability of the North Atlantic thermohaline circulation during the last interglacial period

Studies of natural climate variability are essential for evaluating its future evolution. Greenland ice cores suggest that the modern warm period (the Holocene) has been relatively stable for the past 9,000 years. Much less is known about other warm interglacial periods, which comprise less than 10%...

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Bibliographic Details
Published in:Nature
Main Authors: Adkins, Jess F., Boyle, Edward A., Kelgwin, Lloyd, Cortijo, Elsa
Format: Article in Journal/Newspaper
Language:unknown
Published: Nature Publishing Group 1997
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Online Access:https://doi.org/10.1038/36540
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Summary:Studies of natural climate variability are essential for evaluating its future evolution. Greenland ice cores suggest that the modern warm period (the Holocene) has been relatively stable for the past 9,000 years. Much less is known about other warm interglacial periods, which comprise less than 10% of the climate record during the past 2.5 million years. Here we present high-resolution ocean sediment records of surface and deep-water variables from the Bermuda Rise spanning the last interglacial period, about 118,000–127,000 years ago. In general, deep-water chemical changes are coincident with transitions in surface climate at this site. The records do not show any substantial fluctuations relative to the much higher variability observed during the preceding and subsequent cool climates. The relatively stable interglacial period begins and ends with abrupt changes in deep-water flow. We estimate, using ^(230)Th measurements to constrain the chronology, that transitions occur in less than 400 years. © 1997 Macmillan Publishers Ltd. Received 24 March 1997; Accepted 8 September 1997. This research would not have been possible without the extraordinary efforts of the entire IMAGES 101 crew during the summer of 1995 on board the Marion Dufresne. Specifically we thank Yvon Balut, Laurent Labeyrie, Jean-Louie Turon and Franck Bassinot for their efforts on our behalf. We also thank M. M. Rutgers van der Loeff for helpful comments. J.F.A. was supported by a NASA Global Change Fellowship and a grant from the Tokyo Electric and Power Company. NSF provided the funds to collect this core and NOAA funded our work on high-resolution climate records. Supplemental Material - 36540-s2.pdf Supplemental Material - 390154a0.Suppinfo.xls