# Gulf of Alaska authigenic and bulk sediment neodymium isotope compositions for the past 22,000 years #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/24550 # Description: NOAA Landing Page # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/du2018/du2018-iodp-u1418.txt # Description: NOAA location of the template # # Archive: Paleoceanography # # Dataset_DOI: # # Parameter_Keywords: radiogenic isotope #--------------------------------------- # Contribution_Date # Date: 2018-07-03 #--------------------------------------- # File_Last_Modified_Date # Date: 2018-07-03 #--------------------------------------- # Title # Study_Name: Gulf of Alaska authigenic and bulk sediment neodymium isotope compositions for the past 22,000 years #--------------------------------------- # Investigators # Investigators: Du, Jianghui; Haley, Brian A.; Mix, Alan C. #--------------------------------------- # Description_Notes_and_Keywords # Description: Authigenic neodymium isotope records were generated by leaching non-decarbonated bulk sediments. These records were used to reconstruct North Pacific circulation in the last 22,000 years. Bulk sediment neodymium isotopes were measured by complete microwave digestion of bulk sediments. # Provided Keywords: neodymium isotopes, Gulf of Alaska, North Pacific, Deglaciation, Ocean Circulation #--------------------------------------- # Publication # Authors: Du, Jianghui; Haley, Brian A.; Mix, Alan C.; Walczak, Maureen H.; Praetorius, Summer K. # Published_Date_or_Year: 2018 # Published_Title: Flushing of the deep Pacific Ocean and the deglacial rise of atmospheric CO2 concentrations # Journal_Name: Nature Geoscience # Volume: # Edition: # Issue: # Pages: # Report_Number: # DOI: 10.1038/s41561-018-0205-6 # Online_Resource: # Full_Citation: # Abstract: During the last deglaciation (19,000–9,000 years ago), atmospheric CO2 increased by about 80 ppm. Understanding the mechanisms responsible for this change is a central theme of palaeoclimatology, relevant for predicting future CO2 transfers in a warming world. Deglacial CO2 rise hypothetically tapped an accumulated deep Pacific carbon reservoir, but the processes remain elusive as they are underconstrained by existing tracers. Here we report high-resolution authigenic neodymium isotope data in North Pacific sediment cores and infer abyssal Pacific overturning weaker than today during the Last Glacial Maximum but intermittently stronger during steps of deglacial CO2 rise. Radiocarbon evidence suggestive of relatively ‘old’ deglacial deep Pacific water is reinterpreted here as an increase in preformed 14C age of subsurface waters sourced near Antarctica, consistent with movement of aged carbon out of the deep ocean and release of CO2 to the atmosphere during the abyssal flushing events. The timing of neodymium isotope changes suggests that deglacial acceleration of Pacific abyssal circulation tracked Southern Hemisphere warming, sea-ice retreat and increase of mean ocean temperature. The inferred magnitude of circulation changes is consistent with deep Pacific flushing as a significant, and perhaps dominant, control of the deglacial rise of atmospheric CO2. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation # Grant: OCE-1357529 #--------------------------------------- # Site_Information # Site_Name: IODP U1418 # Location: Gulf of Alaska # Country: # Northernmost_Latitude: 58.8 # Southernmost_Latitude: 58.8 # Easternmost_Longitude: -144.5 # Westernmost_Longitude: -144.5 # Elevation: -3703 #--------------------------------------- # Data_Collection # Collection_Name: IODP-U1418-eNd # First_Year: 21723 # Last_Year: 15715 # Time_Unit: cal yr BP # Core_Length: 36.022272 # Notes: This site is co-located with EW0408-87JC #--------------------------------------- # Chronology_Information # Chronology: #--------------------------------------- # Variables # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## Site notes,,,dimensionless,,Paleoceanography,,,C,Site name ## H IODP Hole number,,,dimensionless,,Paleoceanography,,,C, ## C IODP Core number,,,dimensionless,,Paleoceanography,,,N, ## S IODP Section number,,,dimensionless,,Paleoceanography,,,N, ## Top depth at sample start,,,centimeter,,Paleoceanography,,,N,Depth of the top of sample interval in a section ## Bot depth at sample end,,,centimeter,,Paleoceanography,,,N,Depth of the bottom of sample interval in a section ## t_csf_a depth at sample start,,,meter,,Paleoceanography,,,N,Depth of the top of sample interval on the CSF_A depth scale ## b_csf_a depth at sample end,,,meter,,Paleoceanography,,,N,Depth of the bottom of sample interval on the CSF_A depth scale ## t_ccsf_a depth at sample start,,,meter,,Paleoceanography,,,N,Depth of the top of sample interval on the CCSF_A depth scale ## b_ccsf_a depth at sample end,,,meter,,Paleoceanography,,,N,Depth of the bottom of sample interval on the CCSF_A depth scale ## t_ccsf_b depth at sample start,,,meter,,Paleoceanography,,,N,Depth of the top of sample interval on the CCSF_B depth scale ## b_ccsf_b depth at sample end,,,meter,,Paleoceanography,,,N,Depth of the bottom of sample interval on the CCSF_B depth scale ## ccsf_b_mid depth,,,meter,,Paleoceanography,,,N,Depth of the mid point of sample interval on the CCSF_B depth scale ## Age_16% age,,68% confidence interval lower bound,calendar year before present,,Paleoceanography,,,N,also 16% quantile age; Bchron bayesian age model ## Age_50% age,,,calendar year before present,,Paleoceanography,,,N,median age; Bchron bayesian age model ## Age_84% age,,68% confidence interval upper bound,calendar year before present,,Paleoceanography,,,N,also 84% quantile age; Bchron bayesian age model ## Authigenic_143Nd/144Nd 143Nd/144Nd,oxide and hydroxide minerals,,dimensionless,,Paleoceanography,,multiple collector inductively-coupled plasma mass spectrometry,N,authigenic Fe-Mn oxyhydroxide ## Authigenic_eNd epsilon neodymium,oxide and hydroxide minerals,,epsilon unit,,Paleoceanography,,multiple collector inductively-coupled plasma mass spectrometry,N,authigenic Fe-Mn oxyhydroxide ## Authigenic_eNd_err epsilon neodymium,oxide and hydroxide minerals,two standard deviations,epsilon unit,,Paleoceanography,,multiple collector inductively-coupled plasma mass spectrometry,N,authigenic Fe-Mn oxyhydroxide; long term external reproducibility ## Bulk_sediment_143Nd/144Nd 143Nd/144Nd,sediment,,dimensionless,,Paleoceanography,,multiple collector inductively-coupled plasma mass spectrometry,N, ## Bulk_sediment_eNd epsilon neodymium,sediment,,epsilon unit,,Paleoceanography,,multiple collector inductively-coupled plasma mass spectrometry,N, ## Bulk_sediment_eNd_err epsilon neodymium,sediment,two standard deviations,epsilon unit,,Paleoceanography,,multiple collector inductively-coupled plasma mass spectrometry,N,long term external reproducibility #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: NA Site H C S Top Bot t_csf_a b_csf_a t_ccsf_a b_ccsf_a t_ccsf_b b_ccsf_b ccsf_b_mid Age_16% Age_50% Age_84% Authigenic_143Nd/144Nd Authigenic_eNd Authigenic_eNd_err Bulk_sediment_143Nd/144Nd Bulk_sediment_eNd Bulk_sediment_eNd_err IODP-U1418 C 1 3 16 20 3.16 3.2 3.16 3.2 2.779062 2.81424 2.796651 15630 15715 15801 0.512603566 -0.671701388 0.29 0.512636784 -0.0237151 0.29 IODP-U1418 C 1 4 66 70 5.16 5.2 5.16 5.2 4.537962 4.57314 4.555551 17033 17087 17139 0.512638471 0.009187716 0.29 NA NA NA IODP-U1418 D 2 3 14 18 6.14 6.18 8.12 8.16 7.141134 7.176312 7.158723 17228 17271 17316 0.512659499 0.419382828 0.29 0.512609834 -0.54942795 0.29 IODP-U1418 C 2 3 116 120 12.76 12.8 14.15 14.19 12.4442175 12.4793955 12.4618065 17452 17508 17564 0.512656907 0.368822775 0.29 0.512641256 0.063514519 0.29 IODP-U1418 C 2 5 16 20 14.76 14.8 16.15 16.19 14.2031175 14.2382955 14.2207065 17674 17720 17764 0.512656826 0.367246405 0.29 0.512610694 -0.532663839 0.29 IODP-U1418 D 3 3 6 10 15.56 15.6 18.28 18.32 16.076346 16.111524 16.093935 17771 17812 17850 0.512653745 0.30714359 0.29 0.512635168 -0.055240284 0.29 IODP-U1418 D 3 5 96 100 19.46 19.5 22.18 22.22 19.506201 19.541379 19.52379 17855 17895 17936 0.512665506 0.536558308 0.29 0.51261615 -0.426219052 0.29 IODP-U1418 C 3 3 146 150 22.56 22.6 24.17 24.21 21.2563065 21.2914845 21.2738955 17945 17993 18044 0.512635754 -0.043818834 0.29 0.512618402 -0.382303616 0.29 IODP-U1418 C 3 5 46 50 24.51 24.55 26.12 26.16 22.971234 23.006412 22.988823 18043 18090 18138 0.512651816 0.2695012 0.29 0.512602944 -0.683844581 0.29 IODP-U1418 D 4 2 86 90 24.36 24.4 28.13 28.17 24.7389285 24.7741065 24.7565175 18193 18248 18296 0.512632167 -0.113792096 0.29 0.512666275 0.551565936 0.29 IODP-U1418 D 4 5 36 40 28.36 28.4 32.13 32.17 28.2567285 28.2919065 28.2743175 18772 18809 18847 0.512606516 -0.614160961 0.29 NA NA NA IODP-U1418 C 4 3 96 100 31.56 31.6 34.17 34.21 30.0508065 30.0859845 30.0683955 18918 18962 19021 0.512668736 0.599559914 0.29 0.512692938 1.071672754 0.29 IODP-U1418 C 4 5 6 10 33.66 33.7 36.27 36.31 31.8976515 31.9328295 31.9152405 19435 19729 20015.16 0.512671167 0.646989998 0.29 NA NA NA IODP-U1418 D 5 2 26 30 33.26 33.3 38.12 38.16 33.524634 33.559812 33.542223 20321 20404 20475 0.51264706 0.176740944 0.29 0.512646684 0.169407616 0.29 IODP-U1418 D 5 4 145 149 37.45 37.49 42.31 42.35 37.2095295 37.2447075 37.2271185 21204 21296.5 21402 0.512640489 0.048545203 0.29 NA NA NA IODP-U1418 D 5 6 26 30 39.26 39.3 44.12 44.16 38.801334 38.836512 38.818923 21588 21723 21849 NA NA NA 0.512653943 0.310995486 0.29