ODP1060 MIS 3 Western Boundary Undercurrent Flow Vigour Data Hoogakker, B.A.A.; McCave, I.N. Hoogakker, B.A.A. McCave, I.N. earth science/paleoclimate/paleoceanography (total planktic foraminifers,null,null,percent,null,paleoceanography,null,null,N,cold-water species) earth science/paleoclimate/paleoceanography (delta 18O,Uvigerina peregrina,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (mineral matter,sediment,null,count per gram,null,paleoceanography,null,null,N,>150 microns) earth science/paleoclimate/paleoceanography (cadmium/calcium,Uvigerina peregrina,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (grain size median,null,null,micrometer,null,paleoceanography,null,null,N,silt fraction) earth science/paleoclimate/paleoceanography (age,null,null,radiocarbon year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (total planktic foraminifers,null,null,percent,null,paleoceanography,null,null,N,warm-water species) earth science/paleoclimate/paleoceanography (delta 13C,Uvigerina peregrina,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (mineral matter,sediment,null,count per gram,null,paleoceanography,null,null,N,90 to 150 microns) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP1060>LATITUDE 30.766667>LONGITUDE -74.466667) The Western Boundary Undercurrent (WBUC), off eastern America, is an important component of the Atlantic Meridional Overturning circulation and is the principal route for southward transport of North Atlantic waters and southward return of Southern Source Water (SSW). Here a direct flow speed proxy (mean grain size of the sortable silt) is used to infer the vigour of flow of the palaeo-WBUC at Blake Outer Ridge, (ODP Site 1060, depth 3481 m) during Marine Isotope Stage (MIS) 3. The overall shape of the flow speed proxy record shows a complex pattern of variability, with generally more vigorous flow and larger-scale flow variations between 35 and 60 ka than in the younger part of MIS 3 and MIS 2 (< 35 ka). Six events of reduced bottom flow vigour (Slow Events, SEs) occur. These appear uncorrelated with Heinrich events, but are instead synchronous with the warming phases of Antarctic Warm Events A-1 to A-4 (with one new one, A-1a and one poorly defined, `A-0ŋ). This indicates that Antarctic climate exerts a stronger control on deep flow vigour in the North Atlantic during MIS 3 than Northern Hemisphere climate. The correspondence of SEs with Antarctic warming suggests a weaker WBUC flow due to reduced volume flux at SSW source or reduced SSW density. Because the variability of the lower limb of the WBUC was not connected to sharp North Atlantic changes in temperature, it is unlikely that the Dansgaard/Oeschger cycles were associated with a mode of MOC variation involving whole-ocean overturn, but more likely with perturbations of only the shallow Glacial Gulf StreamŋGlacial Northern Source Intermediate Water cell. Nutrient proxies (benthic carbon isotopes and Cd/Ca of Uvigerina peregrina) at this site show similar trends to the GRIP d18O record. This correlation has previously been attributed mainly to hydrographic and flow changes but is here shown to be better explained by variations in surface ocean productivity and subsequent decomposition of 12C rich organic material on the sea floor. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Hoogakker, B.A.A. Investigator : McCave, I.N. 2007-07-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/5594 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1060-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoogakker2007 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1060-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoogakker2007 English https://www.ncdc.noaa.gov/paleo/study/5594 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp1060-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoogakker2007 Hoogakker, B.A.A., I.N. McCave, and M.J. Vautravers. 2007. Antarctic link to deep flow speed variation during Marine Isotope Stage 3 in the western North Atlantic. Earth and Planetary Science Letters 257, 463ŋ473. START YEAR: 62987 14C yr BP * END YEAR: 23260 14C yr BP -74.466667 30.766667 -74.466667 30.766667