# Bulk sediment nitrogen isotopes from the northern Peru Margin over the last 25 kyr #----------------------------------------------------------------------- # 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/25430 # Description: NOAA Landing Page # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-cdh26-14c.txt # Description: NOAA location of the template # # Archive: Paleoceanography # # Dataset_DOI: # # Parameter_Keywords: nitrogen isotopes, carbon isotopes #--------------------------------------- # Contribution_Date # Date: 2018-10-15 #--------------------------------------- # File_Last_Modified_Date # Date: 2018-10-15 #--------------------------------------- # Title # Study_Name: Bulk sediment nitrogen isotopes from the northern Peru Margin over the last 25 kyr #--------------------------------------- # Investigators # Investigators: Bova, Samantha C.; Herbert, Timothy D.; Altabet, Mark A. #--------------------------------------- # Description_Notes_and_Keywords # Description: # Provided Keywords: deglaciation, upwelling, Younger Dryas #--------------------------------------- # Publication # Authors: Bova, S.C., T.D. Herbert, and M.A. Altabet # Published_Date_or_Year: 2018 # Published_Title: Ventilation of northern and southern sources of aged carbon in the eastern equatorial Pacific during the Younger Dryas rise in atmospheric CO2 # Journal_Name: Paleoceanography and Paleoclimatology # Volume: in press # Edition: # Issue: # Pages: # Report_Number: # DOI: # Online_Resource: # Full_Citation: # Abstract: Atmospheric carbon dioxide (CO2) levels rose by ~90 ppmv during the last deglaciation, but the source of this carbon remains unknown. One popular hypothesis suggests carbon accumulated in the deep Southern Ocean, becoming increasingly radiocarbon (14C)-depleted during the last glacial period, and was released into Antarctic Intermediate Water (AAIW) and, subsequently, the atmosphere during deglaciation. Detection of extremely 14C-deplete carbon in the intermediate-depth tropical oceans during periods of atmospheric CO2 rise was initially considered the "smoking gun" for the hypothesis, but attempts to reproduce the anomalies closer to the Southern Ocean source have largely failed. Here, we present new 14C records from four cores recovered at intermediate depths in the eastern equatorial Pacific (EEP). In the context of additional geochemical records, including benthic foraminiferal stable isotopes and sedimentary nitrogen isotopes, we demonstrate that the extreme 14C anomalies observed during the last deglaciation do not reflect the radiocarbon content of AAIW. We show that, although AAIW likely transported modestly 14C-deplete carbon to the EEP subsurface, the extreme 14C signatures might reflect a distinct source of aged carbon arriving from the north, suggesting the North Pacific helped transport deep ocean carbon to the atmosphere during the last deglaciation. In the EEP, additional local hydrothermal inputs of 14C-free carbon near the Galapagos Islands magnified the already low-14C signatures. Finally, regardless of arrival route (North/South Pacific or hydrothermal), 14C-deplete carbon was released from the EEP subsurface during a late deglacial pulse of renewed upwelling, likely contributing to the Younger Dryas rise in atmospheric CO2. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation # Grant: OCE-1003387 #--------------------------------------- # Site_Information # Site_Name: KNR195-5 CDH26 # Location: Eastern Pacific Ocean # Country: # Northernmost_Latitude: -3.986 # Southernmost_Latitude: -3.986 # Easternmost_Longitude: -81.3086666666667 # Westernmost_Longitude: -81.3086666666667 # Elevation: -1023 #--------------------------------------- # Data_Collection # Collection_Name: CDH26 14C Bova2018 # First_Year: 25521 # Last_Year: 3275 # Time_Unit: cal yr BP # Core_Length: 25.39 # Notes: #--------------------------------------- # Chronology_Information # Chronology: # # Paste Measured Radiocarbon Ages into a table below. Ages from other sources can be included using the depth, calib.14C, and notes columns # Labcode # depth_top # depth_bottom # mat.dated # 14C.raw # 14C.raw_err # datemeth # reservoir age # calib.14C # calib.14C_97.5% confidence interval lower bound # calib.14C_97.5% confidence interval upper bound # calib_method # calib_curve # # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth reservoir age calib.14C calib.14C_97.5% confidence interval lower bound calib.14C_97.5% confidence interval upper bound calib_method calib_curve # OS-84131 96.25 95.75 Neogloboquadrina dutertrei 3970 30 14C AMS 466.8 3730 3641 3823 Bchron IntCal13 # OS-84109 171.75 171.25 Neogloboquadrina dutertrei 5980 35 14C AMS 563 6244 6195 6295 Bchron IntCal13 # OS-84125 203.75 203.25 Neogloboquadrina dutertrei 6320 35 14C AMS 548.4 6594 6499 6661 Bchron IntCal13 # OS-84164 235.75 235.25 Neogloboquadrina dutertrei 7070 35 14C AMS 508.2 7442 7357 7503 Bchron IntCal13 # OS-84113 267.75 267.25 Neogloboquadrina dutertrei 7440 35 14C AMS 515.8 7738 7677 7817 Bchron IntCal13 # OS-84111 325.25 324.75 Neogloboquadrina dutertrei 8550 40 14C AMS 578.6 8873 8726 9003 Bchron IntCal13 # #--------------------------------------- # 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) ## depth_cm depth,,,centimeter,,,,,N, ## age_calyr age,,,calendar year before present,,,,,N, ## benthic_14Cage age,benthic foraminifer,,radiocarbon year before present,,paleoceanography,,accelerator mass spectrometry,N, ## benthic_14Cage_sd Delta 14C,benthic foraminifer,one standard deviation,radiocarbon year,,,,,, ## Labcode sample identification,,,,,,,,C,sample identification used by 14C laboratory #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: NA depth_cm age_calyr benthic_14Cage benthic_14Cage_sd Labcode 235.5 7442 7620 40 OS-103000 421 10191 9840 45 OS-103151 574 11854 11700 55 OS-103153 663 12577 12400 40 OS-103181 784.5 13507.5 13500 75 OS-103150 939.5 14660.5 14,200 90 OS-104319 1156.5 16013.5 14800 65 OS-103154 1400.5 17252.5 16000 60 OS-103182 1741 19683 18050 70 OS-103183 1895 20469 18950 100 OS-103155 2048 21920 19700 90 OS-103001 2386 24223 22300 160 OS-103152