noaa-ocean-21950 Gulf of Alaska Alkenone paleotemperatures, d18Oseawater reconstructions, benthic oxygen isotopes and benthic faunal data for the past 18,000 years Praetorius, S.K.; Mix, A.C.; Davies-Walczak, M.H.; Wolhowe, M.D.; Addison, J.A.; Prahl, F.G. Gulf of Alaska Alkenone paleotemperatures, d18Oseawater reconstructions, benthic oxygen isotopes and benthic faunal data for the past 18,000 years 2017-04-18 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/21950 Investigator S.K. Praetorius Investigator A.C. Mix Investigator M.H. Davies-Walczak Investigator M.D. Wolhowe Investigator J.A. Addison Investigator F.G. Prahl earth science paleoclimate climate reconstructions|paleoceanography depth at sample end,null,null,centimeter,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography depth at sample start,null,null,centimeter,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate paleoceanography alkenone unsaturation index Uk37 prime,null,one standard deviation,dimensionless,null,paleoceanography,null,gas chromatography,N,null earth science paleoclimate paleoceanography alkenone unsaturation index Uk37 prime,null,one standard deviation upper bound,dimensionless,null,paleoceanography,null,gas chromatography,N,null earth science paleoclimate paleoceanography weight,dry sediment,null,gram,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Nonionella earth science paleoclimate paleoceanography delta 18O,Cibicidoides wuellerstorfi,null,per mil VPDB,null,paleoceanography,corrected,null,N,corrected to Uvigerina peregrina d18O equivalent by adding 0.64; Sealevel corrected based on the reconstruction of Waelbroeck et al. 2002 earth science paleoclimate paleoceanography sample identification,null,null,null,null,paleoceanography,null,null,C,core name earth science paleoclimate climate reconstructions|paleoceanography sea surface temperature,alkenone unsaturation index,one standard deviation upper bound,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Prahl et al. 1988 earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,one standard deviation lower bound,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; using G. bulloides earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,one standard deviation upper bound,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; using G. bulloides earth science paleoclimate climate reconstructions|paleoceanography sea surface temperature,alkenone unsaturation index,one standard deviation lower bound,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Prahl et al. 1988 earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,null,per mil PDB,null,climate reconstructions|paleoceanography,corrected,null,N,Calibration: Bemis et al. 1998; sealevel correction based on Waelbroeck et al. 2002; using G. bulloides earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,one standard deviation upper bound,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; using N. pachyderma s. earth science paleoclimate paleoceanography depth,null,null,meter,null,paleoceanography,null,null,N,midpoint depth in core earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Epistominella pacifica earth science paleoclimate paleoceanography total benthic foraminifers,null,null,count,null,paleoceanography,null,null,N,Total benthic fauna earth science paleoclimate paleoceanography delta 18O,Globigerina bulloides,null,per mil,null,paleoceanography,null,isotope ratio mass spectrometry,N,null earth science paleoclimate paleoceanography delta 18O,Neogloboquadrina pachyderma sinistral,null,per mil,null,paleoceanography,null,isotope ratio mass spectrometry,N,null earth science paleoclimate paleoceanography age,null,null,calendar year before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Islandiella earth science paleoclimate climate reconstructions|paleoceanography depth,null,null,meter,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate paleoceanography C37 alkenone,null,null,milligram per gram,null,paleoceanography,null,null,N,concentration of C37 ketone abundance earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Bulimina exilis earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Bulimina striata earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Globobulimina affinis earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Elphidium batialis earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,unidentified: cibicidoides-like earth science paleoclimate climate reconstructions|paleoceanography sample identification,null,null,null,null,climate reconstructions|paleoceanography,null,null,C,core name earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,null,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; using G. bulloides earth science paleoclimate paleoceanography age,null,one standard deviation,calendar year before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography alkenone unsaturation index Uk37 prime,null,one standard deviation lower bound,dimensionless,null,paleoceanography,null,gas chromatography,N,null earth science paleoclimate paleoceanography depth at sample start,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,one standard deviation lower bound,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; using N. pachyderma s. earth science paleoclimate paleoceanography delta 18O,Uvigerina peregrina,null,per mil VPDB,null,paleoceanography,null,isotope ratio mass spectrometry,N,null earth science paleoclimate paleoceanography delta 18O,Cibicidoides wuellerstorfi,null,per mil VPDB,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 18O,Cibicidoides wuellerstorfi,null,per mil VPDB,null,paleoceanography,corrected,null,N,corrected to Uvigerina peregrina d18O equivalent by adding 0.64 earth science paleoclimate climate reconstructions|paleoceanography depth,null,null,meter,null,climate reconstructions|paleoceanography,null,null,N,midpoint depth in core earth science paleoclimate climate reconstructions|paleoceanography age,null,null,calendar year before present,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography sea surface temperature,alkenone unsaturation index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Prahl et al. 1988 earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,null,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; using N. pachyderma s. earth science paleoclimate climate reconstructions|paleoceanography delta 18O,alkenone unsaturation index|delta 18O|sea water,null,per mil PDB,null,climate reconstructions|paleoceanography,null,null,N,Calibration: Bemis et al. 1998; sealevel correction based on Waelbroeck et al. 2002; using N. pachyderma s. earth science paleoclimate paleoceanography delta 18O,Uvigerina peregrina,null,per mil VPDB,null,paleoceanography,corrected,isotope ratio mass spectrometry,N,Sealevel corrected based on the reconstruction of Waelbroeck et al. 2002 earth science paleoclimate paleoceanography depth at sample end,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography grain size class,sediment,null,fraction,null,paleoceanography,null,null,N,Coarse fraction >125 um earth science paleoclimate paleoceanography Uvigerina peregrina,null,null,count,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Bolivina earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Spiroloculina earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Oolina earth science paleoclimate paleoceanography identified foraminifer,null,null,count,null,paleoceanography,null,null,N,Pyrgo earth science paleoclimate paleocean biomarkers earth science paleoclimate paleocean oxygen isotopes earth science paleoclimate paleocean reconstruction earth science paleoclimate paleocean population abundance earth science paleoclimate paleocean age control geoscientificInformation Sea Surface Temperature Reconstruction 18120 cal yr BP 500 cal yr BP Complete 56.96 59.555 -144.5 -136.43 -3680 -682 Ocean Pacific Ocean North Pacific Ocean Gulf Of Alaska EW0408-85JC>LATITUDE 59.555>LONGITUDE -144.1535 Ocean Pacific Ocean North Pacific Ocean Gulf Of Alaska EW0408-26TC/JC>LATITUDE 56.96>LONGITUDE -136.43 Ocean Pacific Ocean North Pacific Ocean Gulf Of Alaska EW0408-87JC>LATITUDE 58.77>LONGITUDE -144.5 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 Praetorius, S.K., A.C. Mix, M.H. Davies, M.D. Wolhowe, J.A. Addison, and F.G. Prahl 2015 Nature 527 362-366 10.1038/nature15753 http://www.nature.com/nature/journal/v527/n7578/full/nature15753.html Davies, M.H., A.C. Mix, J.S. Stoner, J.A. Addison, J. Jaeger, B. Finney, and J. Wiest 2011 Paleoceanography 26 PA2223 10.1029/2010PA002051

Marine sediments from the North Pacific document two episodes of expansion and strengthening of the subsurface oxygen minimum zone (OMZ) accompanied by seafloor hypoxia during the last deglacial transition. The mechanisms driving this hypoxia remain under debate. We present a new high-resolution alkenone palaeotemperature reconstruction from the Gulf of Alaska that reveals two abrupt warming events of 4–5 degrees Celsius at the onset of the Bølling and Holocene intervals that coincide with sudden shifts to hypoxia at intermediate depths. The presence of diatomaceous laminations and hypoxia-tolerant benthic foraminiferal species, peaks in redox-sensitive trace metals, and enhanced 15N/14N ratio of organic matter, collectively suggest association with high export production. A decrease in 18O/16O values of benthic foraminifera accompanying the most severe deoxygenation event indicates subsurface warming of up to about 2 degrees Celsius. We infer that abrupt warming triggered expansion of the North Pacific OMZ through reduced oxygen solubility and increased marine productivity via physiological effects; following initiation of hypoxia, remobilization of iron from hypoxic sediments could have provided a positive feedback on ocean deoxygenation through increased nutrient utilization and carbon export. Such a biogeochemical amplification process implies high sensitivity of OMZ expansion to warming. STUDY NOTES: Alkenone paleotemperatures, d18Oseawater reconstructions, and benthic faunal data in this worksheet are from jumbo piston core EW0408-85JC in the Gulf of Alaska. The age model for this core is previously published in Davies-Walczak et al., 2014 (DOI: 10.1016/j.epsl.2014.04.004). Additional benthic oxygen isotope data is provided from cores EW0408-87JC and EW0408-26JC in the Gulf of Alaska, along with the radiocarbon chronology for EW0408-87JC. Source reference for EW0408-26JC age model- Praetorius, S.K. and A.C., Science, 2014 (DOI: 10.1126/science.1252000). Please cite original reference when using this data and consult original publication for details on radiocarbon chronology. Sediment concentrations (K37's mg/g) are not reported for a small number of samples for which analysis of the recovery standard was compromised (indicated with NAN). Provided Keywords: ocean hypoxia, deglacial, oxygen minimum zone, alkenone paleotemperature

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-nps-d18o-85jc.txt Formatted Text File; EW0408-85JC N. pachy-s. d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-faunal-85jc.txt Formatted Text File; EW0408-85JC Benthic Faunal Count Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-gbull-d18o-85jc.txt Formatted Text File; EW0408-85JC G. bulloides d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-age-85jc.txt Formatted Text File; EW0408-85JC Age Model GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-87jc.txt Formatted Text File; EW0408-87JC d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-26jc.txt Formatted Text File; EW0408-26TC/JC d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/praetorius2015/praetorius2015-alkenone-85jc.txt Formatted Text File; EW0408-85JC Alkenone SST Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11