Rapid reductions in North Atlantic Deep Water during the peak of the last interglacial period

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doi: 10.1126/science.1248667
Author(s): Galaasen, Eirik Vinje; Ninnemann, Ulysses S.; Irvali, Nil; Kleiven, Helga F.; Rosenthal, Yair; Kissel, Catherine; Hodell, David A.
Author Affiliation(s): Primary:
University of Bergen, Department of Earth Science, Bergen, Norway
Other:
Rutgers, the State University of New Jersey, United States
Université de Versailles Saint-Quentin, France
Institut Pierre Simon Laplace, France
University of Cambridge, United Kingdom
Volume Title: Science
Source: Science, 343(6175), p.1129-1132. Publisher: American Association for the Advancement of Science, Washington, DC, United States. ISSN: 0036-8075 CODEN: SCIEAS
Note: In English. 36 refs.; illus., incl. sketch map
Summary: Deep ocean circulation has been considered relatively stable during interglacial periods, yet little is known about its behavior on submillennial time scales. Using a subcentennially resolved epibenthic foraminiferal δ13C record, we show that the influence of North Atlantic Deep Water (NADW) was strong at the onset of the last interglacial period and was then interrupted by several prominent centennial-scale reductions. These NADW transients occurred during periods of increased ice rafting and southward expansions of polar water influence, suggesting that a buoyancy threshold for convective instability was triggered by freshwater and circum-Arctic cryosphere changes. The deep Atlantic chemical changes were similar in magnitude to those associated with glaciations, implying that the canonical view of a relatively stable interglacial circulation may not hold for conditions warmer and fresher than at present.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; C-13/C-12; Cape Basin; Carbon; Cenozoic; Cores; Expedition 303; Expeditions 303/306; Foraminifera; IODP Site U1304; Integrated Ocean Drilling Program; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Leg 177; Marine sediments; Microfossils; North Atlantic; North Atlantic Deep Water; Northeast Atlantic; ODP Site 1089; Ocean Drilling Program; Ocean circulation; Paleo-oceanography; Paleoclimatology; Pleistocene; Protista; Quaternary; Reconstruction; Sediments; South Atlantic; Stable isotopes
Coordinates: N530300 N530300 W0333200 W0333200
S405611 S405611 E0095338 E0095338
Record ID: 2014030336
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.