Federici, Luna and McManus, Jerry F. (2003): Ocean circulation and climate during the Stage 11 interglacial interval

Leg/Site/Hole:
ODP 162
ODP 162 984
Identifier:
2007-002363
georefid

Creator:
Federici, Luna
Stanford University, Department of Geological and Environmental Sciences, Palo Alto, CA, United States
author

McManus, Jerry F.
Woods Hole Oceanographic Institution, United States
author

Identification:
Ocean circulation and climate during the Stage 11 interglacial interval
2003
In: Anonymous, XVI INQUA congress; Shaping the Earth; a Quaternary perspective; programs with abstracts
[International Union for Quaternary Research], International
16
138
The Marine Isotope Stage 11 (MIS 11), an interglacial of 400ka is the period in the Pleistocene most similar to the Holocene in climate forcing by insolation and naturally occurring greenhouse gases and thus can be studied as an analog for the present and future climate. This project is a high-resolution analysis of the Stage 11 interglacial using a marine sediment core from ODP Site 984 on the Reykjanes Ridge in the North Atlantic. A multi-proxy approach is used to investigate the 'super' interglacial climate and ocean circulation of 400ka. The ice-rafting debris and sortable silt records from this period both demonstrate millennial scale variability, as in the Holocene. The sortable silt data indicate that thermohaline circulation varied in a similar fashion during Stage 11 as in the Holocene. These results suggest the existence of a persistent internal mode of variability in the ocean circulation-climate system. The ice-rafted debris levels in Stage 11 allow for the possibility of a diminished Greenland ice sheet, particularly late in the progression of the interglacial, beyond the elapsed duration of the Holocene. A glacial amplifier with a 18O threshold value of 3.5 per mil emerges from the paired IRD and isotope data, as do lower frequency circulation cycles from the sortable silt mean signal. An estimate of 16,500 -22,000 years for the duration of Stage 11 interglacial suggests that if these two similarly forced interglacials follow similar trajectories, the Holocene interglacial warmth would naturally continue many thousands of years into the future in the absence of anthropogenic perturbation.
English
Coverage:Geographic coordinates:
North:61.2532
West:-24.0457East: -24.0457
South:61.2532

Quaternary geology; Arctic region; Atlantic Ocean; Cenozoic; climate; debris; Greenland; Greenland ice sheet; ice rafting; interglacial environment; isotope ratios; isotopes; Leg 162; marine sediments; North Atlantic; O-18/O-16; ocean circulation; Ocean Drilling Program; ODP Site 984; oxygen; paleo-oceanography; Pleistocene; Quaternary; Reykjanes Ridge; sediments; stable isotopes;

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