Eastern Subpolar North Atlantic Stable Isotope, Mg/Ca and SST Data During the Last Deglaciation Benway, H.M.; McManus, J.F.; Oppo, D.W.; Cullen, J.L. Benway, H.M. McManus, J.F. Oppo, D.W. Cullen, J.L. earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,composited,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerina falconensis) earth science/paleoclimate/paleoceanography (Neogloboquadrina pachyderma sinistral,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Globorotalia inflata,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Globorotalia truncatulinoides,null,null,percent,null,paleoceanography,null,null,N,right coiling) earth science/paleoclimate/paleoceanography (Globorotalia crassaformis,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerinella calida) earth science/paleoclimate/paleoceanography (Globigerina bulloides,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Globorotalia truncatulinoides,null,null,percent,null,paleoceanography,null,null,N,left coiling) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globorotalia scitula) earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Neogloboquadrina pachyderma dextral,null,per mil VPDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Neogloboquadrina pachyderma sinistral,null,null,percent,null,paleoceanography,null,null,N,left coiling) earth science/paleoclimate/paleoceanography (Globorotalia menardii,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Orbulina universa,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Globigerinella siphonifera,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globoturborotalita rubescens) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerina quinqueloba) earth science/paleoclimate/paleoceanography (magnesium/calcium,Neogloboquadrina pachyderma sinistral,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Trilobatus sacculifer,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Truncatulina humilis) earth science/paleoclimate/paleoceanography (Pulleniatina obliquiloculata,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (ice rafted debris,null,null,count per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Globorotalia hirsuta,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerinita glutinata) earth science/paleoclimate/paleoceanography (delta 18O,benthic foraminifer,null,per mil VPDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,delta 18O,null,degree Celsius,summer,climate reconstructions|paleoceanography,null,modern analogue technique,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerinoides conglobata) earth science/paleoclimate/paleoceanography (Globigerinoides ruber,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globoturborotalita tenella) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerina digitata) earth science/paleoclimate/paleoceanography (Neogloboquadrina dutertrei,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globorotalia theyeri) earth science/paleoclimate/paleoceanography (total foraminifers,null,null,count,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Neogloboquadrina pachyderma sinistral,null,per mil VPDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (Neogloboquadrina pachyderma dextral,null,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,From Neogloboquadrina pachyderma dextral 14C dates) earth science/paleoclimate/paleoceanography (magnesium/calcium,Neogloboquadrina pachyderma dextral,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,cadmium/calcium,null,degree Celsius,winter,climate reconstructions|paleoceanography,null,modern analogue technique,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,Globigerinita iota) earth science/paleoclimate/paleoceanography (identified foraminifer,null,null,percent,null,paleoceanography,null,null,N,unidentified foraminifera) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 980>LATITUDE 55.48>LONGITUDE -14.7) Millennial-scale climate fluctuations of the last deglaciation have been tied to abrupt changes in the Atlantic Meridional Overturning Circulation (MOC). A key to understanding mechanisms of MOC collapse and recovery is the documentation of upper ocean hydrographic changes in the vicinity of North Atlantic deep convection sites. Here we present new high-resolution ocean temperature and d18Osw records spanning the last deglaciation from an eastern subpolar North Atlantic site that lies along the flow path of the North Atlantic Current, approaching deep convection sites in the Labrador and Greenland-Iceland-Norwegian (GIN) Seas. High-resolution temperature and d18Osw records from subpolar Site 980 help track the movement of the subpolar/subtropical front associated with temperature and Atlantic MOC changes throughout the last deglaciation. Distinct d18Osw minima during Heinrich 1 (H1) and the Younger Dryas (YD) correspond with peaks in ice-rafted debris and periods of reduced Atlantic MOC, indicating the presence of melt water in this region that could have contributed to MOC reductions during these intervals. Increased tropical and subtropical d18Osw during these periods of apparent freshening in the subpolar North Atlantic suggest a buildup of salt at low latitudes that served as a negative feedback on reduced Atlantic MOC. STUDY NOTES: The chronology for ODP Site 980 is based on 35 monospecific foraminifera accelerator mass spectrometry (AMS) 14C dates (Globigerina bulloides, N. pachyderma (d), N. pachyderma (s)) spanning from the LGM to the late Holocene (Table 1 in publication). The Calib (Stuiver and Reimer, 1993) program (version 6.0, Marine09 calibration data set of Reimer et al., 2009) was used to convert 14C ages to calendar ages. The resulting age model suggests an average sedimentation rate of ~23 cm/ky throughout the deglacial interval. Calendar age differences between N. pachyderma (s) and N. pachyderma (d) at the same depths (Table 1) are mostly on the order of 100-200 years, except for a ~900-year difference just prior to the onset of the BA, which may reflect age differences in polar vs. subpolar water masses. These age discrepancies are taken into account by applying slightly different age models for N. pachyderma (s) vs. N. pachyderma (d) records (based on dual ages obtained at the four depth intervals listed in Table 1 in publication). Paired geochemical measurements of two planktonic foraminifer species, Neogloboquadrina pachyderma (dextral (d), or right-coiling) and N. pachyderma (sinistral (s), or left-coiling), constrain changes in upper ocean temperature and salinity and their relationship to global climate and deep ocean circulation. The oxygen isotope composition of foraminiferal calcite (d18Oc) reflects both ambient calcification temperature and seawater isotopic composition (d18Osw). Independent estimates of calcification temperature from Mg/Ca measurements differentiate temperature and d18Osw influences on d18Oc. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Benway, H.M. Investigator : McManus, J.F. Investigator : Oppo, D.W. Investigator : Cullen, J.L. 2013-05-15 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/14413 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/benway2010/benway2010-fauna.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/benway2010/benway2010.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/benway2010/benway2010-fauna.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/benway2010/benway2010.txt English https://www.ncdc.noaa.gov/paleo/study/14413 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/benway2010/benway2010-fauna.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/benway2010/benway2010.txt Benway, H.M., J.F. McManus, D.W. Oppo, and J.L. Cullen. 2010. Hydrographic changes in the eastern subpolar North Atlantic during the last deglaciation. Quaternary Science Reviews, 29, 3336-3345. DOI:10.1016/j.quascirev.2010.08.013. START YEAR: 22000 cal yr BP * END YEAR: 10000 cal yr BP -14.7 55.48 -14.7 55.48