# Arrowhead Lake, Greenland, XRF, Magnetic Susceptibility and d18O Data Over the Past 8300 Years #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # Template Version 4.0 # Encoding: UTF-8 # NOTE: Please cite original publication, NOAA Landing Page URL, dataset and publication DOIs (where available), and date accessed when using downloaded data. # If there is no publication information, please cite investigator, study title, NOAA Landing Page URL, and date accessed. # # Description/Documentation lines begin with '#' followed by a space # Data lines have no '#' # # NOAA_Landing_Page: https://www.ncei.noaa.gov/access/paleo-search/study/39079 # Landing_Page_Description: NOAA Landing Page of this file's parent study, which includes all study metadata. # # Study_Level_JSON_Metadata: https://www.ncei.noaa.gov/pub/data/metadata/published/paleo/json/noaa-lake-39079.json # Study_Level_JSON_Description: JSON metadata of this data file's parent study, which includes all study metadata. # # Data_Type: Paleolimnology # # Dataset_DOI: # # Science_Keywords: Arctic #--------------------------------------- # Resource_Links # # Data_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/paleolimnology/greenland/edgerton2024/edgerton2024-18arwu1_chironomid_isotope.txt # Data_Download_Description: NOAA Template File; Chironomid Isotope Data # #--------------------------------------- # Contribution_Date # Date: 2024-02-27 #--------------------------------------- # File_Last_Modified_Date # Date: 2024-02-27 #--------------------------------------- # Title # Study_Name: Arrowhead Lake, Greenland, XRF, Magnetic Susceptibility and d18O Data Over the Past 8300 Years #--------------------------------------- # Investigators # Investigators: Edgerton, Briana (https://orcid.org/0009-0001-0140-6841); Axford, Yarrow (https://orcid.org/0000-0002-8033-358X); Chipman, Melissa. (https://orcid.org/0000-0002-6872-8829) #--------------------------------------- # Description_Notes_and_Keywords # Description: Oxygen isotope measurements on chitin, age model information, magnetic susceptibility, and geochemical measurements from lake sediment core 18ARWU1, Arrowhead Lake (informal name), Greenland # Provided Keywords: paleoclimate, age control, geochemistry, oxygen isotopes, magnetic susceptibility #--------------------------------------- # Publication # Authors: Edgerton, B., Axford, A., and Chipman, M.L. # Published_Date_or_Year: 2024 # Published_Title: Evaluating Middle to Late Holocene climate variabilty from chitin d18O in southwestern Greenland # Journal_Name: Quaternary Science Reviews # Volume: # Edition: # Issue: # Pages: # Report_Number: # DOI: # Online_Resource: # Full_Citation: # Abstract: Paleotemperature records from ice-free margins of Greenland suggest spatiotemporal heterogeneity in the timing of key climate transitions following retreat of the Greenland Ice Sheet. However, the paucity of high-resolution climate records from this region limits our understanding of the timing, spatial variation, and drivers of Holocene climate variability. Here, we present a middle to late Holocene climate reconstruction based on chitin d18O and sediment geochemistry from lake sediments to elucidate millennial to submillennial-scale drivers of climate in southwestern Greenland. We establish that our site, Arrowhead Lake, is a through-flowing basin with an integrated signal of annual meteoric water with no evidence of evaporative enrichment. Core sediment geochemistry captures the transition from minerogenic-dominated to organic-rich sediments ~8 cal ka BP. Chitin-based d18O measurements of both chironomid head capsules and ephippia exhibit similar temporal variability through the record, broadly decreasing from 8.2 cal ka BP to present, concurrent with decreasing summer insolation and regional Neoglacial cooling. We estimate an average temperature change from the middle to late Holocene at Arrowhead Lake of 2 – 3 ?, comparable to existing chitin d18O estimates of temperature in western Greenland. Depleted d18O values after 3.3 cal ka BP corresponds to the onset of Neoglacial cooling and a slowdown of the Western Greenland Current, and suggests that both temperature and sea-ice variability were important controls on isotopic variability at this site. Highly depleted isotopic values at 8.2 cal ka BP followed by high isotopic variability in the early part of the middle Holocene suggests that our record may capture regional 8.2 ka cooling . This new isotope record provides insight into climate influences during the middle and late Holocene along the western Greenland margin that are important for understanding how ongoing melt of the Greenland Ice Sheet and amplified warming in the Arctic may impact the climate system. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Geographic Society # Grant: NGS-393R-1 #--------------------------------------- # Site_Information # Site_Name: Arrowhead Lake # Location: Greenland # Northernmost_Latitude: 66.9077 # Southernmost_Latitude: 66.9077 # Easternmost_Longitude: -51.8561 # Westernmost_Longitude: -51.8561 # Elevation_m: 389 #--------------------------------------- # Data_Collection # Collection_Name: 18ARWU1_Chironomid_Isotope # First_Year: 8214 # Last_Year: -68 # Time_Unit: calendar year before present # Core_Length_m: 0.725 # Parameter_Keywords: oxygen isotopes # Notes: #--------------------------------------- # Chronology_Information # Chronology: # # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth calib.14C calib.14C_2sig_lo calib.14C_2sig_up calib_method # 18ARWU1_5cm_CD 5 5.5 aquatic moss 1100 15 14C AMS 997 957 1057 Calib v8.2 IntCal 20 # 18ARWU1_11cm_CD 11 11.5 mixed material 1880 200 14C AMS 1811 1385 2184 Calib v8.2 IntCal 20 # 18ARWU1_16.5cm_CD 16.5 17 grass 2720 55 14C AMS 2824 2748 2939 Calib v8.2 IntCal 20 # 18ARWU1_22.5cm_CD 22.5 23 aquatice moss 2070 20 14C AMS 2030 1947 2107 Calib v8.2 IntCal 20 # 18ARWU1_26cm_CD 26 26.5 ephippia 4170 65 14C AMS 4698 4526 4845 Calib v8.2 IntCal 20 # 18ARWU1_28cmCD 28 28.5 ephippia 4360 60 14C AMS 4946 4831 5274 Calib v8.2 IntCal 20 # 18ARWU1_30cmCD 30 30.5 ephippia 4780 55 14C AMS 5513 5327 5596 Calib v8.2 IntCal 20 # 18ARWU1_33cmCD 33 33.5 mixed material 5290 40 14C AMS 6080 5939 6192 Calib v8.2 IntCal 20 # 18ARWU1_35cmCD 35 35.5 mixed material 6210 70 14C AMS 7097 5907 7269 Calib v8.2 IntCal 20 # 18ARWU1_41.5cm_CD 41.5 42 bark/twig 7340 190 14C AMS 8153 7787 8520 Calib v8.2 IntCal 20 # 18ARWU1_46.5cmCD 46.5 47 ephippia 7220 160 14C AMS 8044 7736 5362 Calib v8.2 IntCal 20 # 18ARWU1_48.5cm_CD 48.5 49 moss 7290 330 14C AMS 8120 7505 8975 Calib v8.2 IntCal 20 # 18ARWU1_51.5cmCD 51.5 52  mixed material 6540 70 14C AMS 7451 7319 7319 Calib v8.2 IntCal 20 # #--------------------------------------- # Variables # PaST_Thesaurus_Download_Resource: https://www.ncei.noaa.gov/access/paleo-search/skos/past-thesaurus.rdf # PaST_Thesaurus_Download_Description: Paleoenvironmental Standard Terms (PaST) Thesaurus terms, definitions, and relationships in SKOS format. # # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-var components: what, material, error, units, seasonality, data type, detail, method, C or N for Character or Numeric data) # ## depth_cm depth,,,centimeter ,,paleolimnology ,,,N ,depth in cm below sediment water interface ## age_BP age ,,,calendar year Before Present ,,paleolimnology ,,,N,age of sample ## d18O_chiron delta 18O,,,per mil VSMOW,,paleolimnology ,,isotope ratio mass spectrometry ,N,oxygen isotope of chronomid head capsules; temperature conversion elemental analysis IRMS ## d18O_chiron_error delta 18O,,,per mil VSMOW,,paleolimnology ,,isotope ratio mass spectrometry ,N,d18O analytical error (1-sigma error); unspecified margin of error #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: NA depth_cm age_BP d18O_chiron d18O_chiron_error 0 -68 8.7 1.11 4 821 9.4 1.11 6 1176 10.0 1.11 8 1442 9.2 1.11 10 1708 10.1 1.11 12 2071 10.2 1.11 14 2435 10.0 1.11 16 2771 9.7 1.11 18 3081 9.4 1.11 20 3391 12.4 1.11 22 3813 10.6 1.11 24 4235 12.2 1.11 25 4447 9.8 1.11 26 4627 11.2 1.11 27 4807 12.5 1.11 28 4987 11.3 1.11 29 5167 11.4 1.11 30 5347 11.9 1.11 31 5636 11.1 1.11 32 5925 11.2 1.11 33 6215 11.1 1.11 34 6504 11.2 1.11 36 6968 11.5 1.11 38 7317 10.8 1.11 39 7492 10.4 1.11 40 7667 11.7 1.11 41 7724 11.2 1.11 42 7781 12.3 1.11 43 7838 8.2 1.11 44 7896 11.0 1.11 45 7953 11.4 1.11 46 7990 11.7 1.11 48 8065 12.8 1.11 49 8103 11.3 1.11 50 8140 11.3 1.11 51 8214 7.9 1.11