noaa-ocean-16559 Iceland Basin Sortable Silt Data During the Holocene Thornalley, D.J.R.; Blaschek, M.; Davies, F.J.; Praetorius, S.K.; Oppo, D.W.; McManus, J.F.; Hall, I.R.; Kleiven, H.; Renssen, H.; McCave, I.N. Iceland Basin Sortable Silt Data During the Holocene 2014-06-06 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/16559 Investigator D.J.R. Thornalley Investigator M. Blaschek Investigator F.J. Davies Investigator S.K. Praetorius Investigator D.W. Oppo Investigator J.F. McManus Investigator I.R. Hall Investigator H. Kleiven Investigator H. Renssen Investigator I.N. McCave earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,averaged,null,N,average of individual cores earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,null,null,N,1575-1750m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,averaged,null,N,average using depth groups earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,averaged,null,N,average using depth groups earth science paleoclimate paleoceanography age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,averaged,null,N,weighted average at depths >1.3km using depth groups earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,null,null,N,1200-1375m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,averaged,null,N,weighted average at depths >1.3km using depth groups earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,null,null,N,1575-1750m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,null,null,N,1750-2250m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,averaged,null,N,weighted average using depth groups earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,null,null,N,1375-1575m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,null,null,N,1750-2250m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,averaged,null,N,average of individual cores earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,anomalized,null,N,centered around core mean earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,null,null,N,1375-1575m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,two standard deviations,micrometer,null,paleoceanography,null,null,N,1200-1375m depth earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography sortable silt mean grain size,null,null,micrometer,null,paleoceanography,averaged,null,N,weighted average using depth groups earth science paleoclimate paleocean physical properties geoscientificInformation 12120 cal yr BP 0 cal yr BP Complete 60.4 62.9755 -24.172167 -17.5895 -2260 -1188 Ocean Atlantic Ocean North Atlantic Ocean EW9302-30GGC>LATITUDE 62.7505>LONGITUDE -20.6775 Ocean Atlantic Ocean North Atlantic Ocean EW9302-22GGC>LATITUDE 61.421333>LONGITUDE -21.893 Ocean Atlantic Ocean North Atlantic Ocean EW9302-29GGC>LATITUDE 62.612333>LONGITUDE -20.6375 Ocean Atlantic Ocean North Atlantic Ocean EW9302-25GGC>LATITUDE 62.063>LONGITUDE -21.472167 Ocean Atlantic Ocean North Atlantic Ocean EW9302-24GGC>LATITUDE 61.762833>LONGITUDE -21.667667 Ocean Atlantic Ocean North Atlantic Ocean ODP 983>LATITUDE 60.4>LONGITUDE -23.63 Ocean Atlantic Ocean North Atlantic Ocean EW9302-26GGC>LATITUDE 62.321667>LONGITUDE -21.457333 Ocean Atlantic Ocean North Atlantic Ocean NEAP-4K>LATITUDE 61.4985>LONGITUDE -24.172167 Ocean Atlantic Ocean North Atlantic Ocean RAPiD-10-1P>LATITUDE 62.9755>LONGITUDE -17.5895 Ocean Atlantic Ocean North Atlantic Ocean EW9302-32GGC>LATITUDE 61.346>LONGITUDE -20.348833 Ocean Atlantic Ocean North Atlantic Ocean ODP 984>LATITUDE 61.43>LONGITUDE -24.08 Ocean Atlantic Ocean North Atlantic Ocean EW9302-23GGC>LATITUDE 61.672>LONGITUDE -21.732667 Ocean Atlantic Ocean North Atlantic Ocean EW9302-11GGC>LATITUDE 60.403333>LONGITUDE -23.640667 Ocean Atlantic Ocean North Atlantic Ocean Iceland Basin>LATITUDE >LONGITUDE None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Thornalley, D. J. R., Blaschek, M., Davies, F. J., Praetorius, S., Oppo, D. W., McManus, J. F., Hall, I. R., Kleiven, H., Renssen, H., and McCave, I. N. 2013 Climate of the Past 9 2073-2084 10.5194/cp-9-2073-2013

The overflow of deep water from the Nordic seas into the North Atlantic plays a critical role in global ocean circulation and climate. Approximately half of this overflow occurs via the Iceland–Scotland (I–S) overflow, yet the history of its strength throughout the Holocene (~ 0–11 700 yr ago, ka) is poorly constrained, with previous studies presenting apparently contradictory evidence regarding its long-term variability. Here, we provide a comprehensive reconstruction of I–S overflow strength throughout the Holocene using sediment grain size data from a depth transect of 13 cores from the Iceland Basin. Our data are consistent with the hypothesis that the main axis of the I–S overflow on the Iceland slope was shallower during the early Holocene, deepening to its present depth by ~ 7 ka. Our results also reveal weaker I–S overflow during the early and late Holocene, with maximum overflow strength occurring at ~ 7 ka, the time of a regional climate thermal maximum. Climate model simulations suggest a shoaling of deep convection in the Nordic seas during the early and late Holocene, consistent with our evidence for weaker I–S overflow during these intervals. Whereas the reduction in I–S overflow strength during the early Holocene likely resulted from melting remnant glacial ice sheets, the decline throughout the last 7000 yr was caused by an orbitally induced increase in the amount of Arctic sea ice entering the Nordic seas. Although the flux of Arctic sea ice to the Nordic seas is expected to decrease throughout the next century, model simulations predict that under high emissions scenarios, competing effects, such as warmer sea surface temperatures in the Nordic seas, will result in reduced deep convection, likely driving a weaker I–S overflow.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-26ggc.txt Formatted Data File; EW9302-26GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-32ggc.txt Formatted Data File; EW9302-32GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-11ggc.txt Formatted Data File; EW9302-11GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-29ggc.txt Formatted Data File; EW9302-29GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-neap4k.txt Formatted Data File; NEAP-4K Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-stack.txt Formatted Data File; Sortable Silt by Stack Technique GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-odp983.txt Formatted Data File; ODP983 Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-10-1p.txt Formatted Data File; RAPiD-10-1P Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-23ggc.txt Formatted Data File; EW9302-23GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-24ggc.txt Formatted Data File; EW9302-24GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-depth.txt Formatted Data File; Sortable Silt by Depth Group GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-22ggc.txt Formatted Data File; EW9302-22GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-25ggc.txt Formatted Data File; EW9302-25GGC Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-odp984.txt Formatted Data File; ODP984 Sortable Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/thornalley2013-cop/thornalley2013-cop-30ggc.txt Formatted Data File; EW9302-30GGC Sortable Silt Data USA/NOAA DIF Version 9.8.4 2019-06-07 2019-06-07