# West Greenland Holocene Lake Sediment Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original reference when using these data, # plus the Online Resource and date accessed. # # # Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:13664 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/greenland/loon2013.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleolimnology #-------------------- # Contribution_Date # Date: 2012-12-13 #-------------------- # Title # Study_Name: West Greenland Holocene Lake Sediment Data #-------------------- # Investigators # Investigators: Axford, Y.; Losee, S.; Briner, J.P.; Francis, D.R.; Langdon, P.G.; Walker, I.R. #-------------------- # Description_and_Notes # # Lake sediment proxy data from 5 Holocene lakes in West Greenland, located between Disko Bugt and the Greenland Ice Sheet near the coastal town of Ilulissat. # Proxy data include Magnetic Susceptibility (MS), Loss-on-Ignition (LOI), Biogenic Silica, and chironomid assembledges. # #-------------------- # Publication # Authors: Yarrow Axford, Shanna Losee, Jason P. Briner, Donna R. Francis, Peter G. Langdon, Ian R. Walker # Published_Date_or_YEAR: 2013-01-03 # Published_Title: Holocene temperature history at the western Greenland Ice Sheet margin reconstructed from lake sediments # Journal_Name: Quaternary Science Reviews # Volume: 59 # Issue: # Pages: 87-100 # DOI: 10.1016/j.quascirev.2012.10.024 # Abstract: Predicting the response of the Greenland Ice Sheet to future climate change presents a major challenge to climate science. Paleoclimate data from Greenland can provide empirical constraints on past cryospheric responses to climate change, complementing insights from contemporary observations and from modeling. Here we examine sedimentary records from five lakes near Jakobshavn Isbrae in central West Greenland to investigate the timing and magnitude of major Holocene climate changes, for comparison with glacial geologic reconstructions from the region. A primary objective of this study is to constrain the timing and magnitude of maximum warmth during the early to middle Holocene positive anomaly in summer insolation. Temperature reconstructions from subfossil insect (chironomid) assemblages suggest that summer temperatures were warmer than present by at least 7.1 ka (the beginning of the North Lake record; ka = thousands of years before present), and that the warmest millennia of the Holocene occurred in the study area between 6 and 4 ka. Previous studies in the Jakobshavn region have found that the local Greenland Ice Sheet margin was most retracted behind its present position between 6 and 5 ka, and here we use chironomids to estimate that local summer temperatures were 2-3°C warmer than present during that time of minimum ice sheet extent. As summer insolation declined through the late Holocene, summer temperatures cooled and the local ice sheet margin expanded. Gradual, insolation-driven millennial-scale temperature trends in the study area were punctuated by several abrupt climate changes, including a major transient event recorded in all five lakes between 4.3 and 3.2 ka, which overlaps in timing with abrupt climate changes previously documented around the North Atlantic region and farther afield at ~4.2 ka. # #--------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: ARC-0909347, ARC-0909334, BCS-0752848 #--------------------- # Funding_Agency_Name: Initiative for Sustainability and Energy at Northwestern University (ISEN) # Grant: #-------------------- # Site_Information # Site_Name: Loon Lake # Location: North America>Greenland # Country: Greenland # Northernmost_Latitude: 69.05815 # Southernmost_Latitude: 69.05815 # Easternmost_Longitude: -49.91605 # Westernmost_Longitude: -49.91605 # Elevation: 278 m #------------------ # Data_Collection # Core_Name: Loon2013LOIMS # First_Year: 7472 # Last_Year: -59 # Time_Unit: Cal Year BP # Core_Length: 0.077 # Notes: #------------------ # Chronology # # Table 2 # Radiocarbon ages from lake sediment cores # # Core Depth Lab Number Material Dated Fraction Modern d13C Radiocarbon Age Calibrated Age # (cm) (‰PDB) (14C yr BP) (cal yr BP ± 2S) # # Loon Lake # 08LOO-1 20 CURL-10094 plant macrofossils 0.6180±0.0009 -37.7 3865±15 4320±90 # 08LOO-1 32 CURL-10104 plant macrofossils 0.5604±0.0010 -32.1 4655±15 5390±70 # 08LOO-1 46 CURL-10088 plant macrofossils 0.5265±0.0009 -34.5 5155±15 5920±70 # 08LOO-1 61 CURL-10101 plant macrofossils 0.5206±0.0008 -29.5 5525±15 6340±50 # # North Lake # 08NOR-3 23 CURL-10089 plant macrofossils 0.7265±0.0010 -28.1 2565±15 2680±60 # 08NOR-3 40 CURL-12613 plant macrofossils 0.6746±0.0013 -24.0 3160±20 3400±40 # 08NOR-3 61 CURL-12600 plant macrofossils 0.5928±0.0009 -24.9 4200±15 4740±90 # 08NOR-3 74 CURL-10091 plant macrofossils 0.5562±0.0010 -28.6 4715±20 5450±130 # 08NOR-3 100 CURL-12603 plant macrofossils 0.4631±0.0008 -28.8 6185±15 7090±80 # 08NOR-3 103 CURL-10092 plant macrofossils 0.4006±0.0008 -12.7 7350±20 8160±120 # # Fishtote Lake # 09FTL-SC2 2 CURL-12593 plant macrofossils 0.7864±0.0012 -21.8 1930±15 1860±40 # 09FTL-SC2 36 CURL-12606 plant macrofossils 0.6438±0.0009 -28.0 3540±15 3810±80 # 09FTL-SC2 65 CURL-12601 plant macrofossils 0.4995±0.0008 -24.0 5575±15 6360±50 # 09FTL-SC2 96 CURL-12608 plant macrofossils 0.367±0.0009 -27.6 8050±20 8910±120 # # Iceboom Lake # 08ICE-5 23 CURL-10083 plant macrofossils 0.9591±0.0015 -23.5 335±15 390±80 # 08ICE-5 36 CURL-10439 plant macrofossils 0.7952±0.0019 -27.8 1840±20 1770±60 # 08ICE-5 57 CURL-10434 plant macrofossils 0.6098±0.0015 -30.7 3980±20 4470±50 # 08ICE-5 70 CURL-10441 plant macrofossils 0.4534±0.0013 -30.5 6360±25 7300±120 # # Pluto Lake # 09PLO-1 4 CURL-12609 plant macrofossils 0.7539±0.0010 -29.7 2270±15 2260±80 # 09PLO-1 25 CURL-12599 plant macrofossils 0.6232±0.0012 -28.7 3800±20 4170±70 # 09PLO-1 50 CURL-12604 plant macrofossils 0.4050±0.0011 -14.9 7260±25 8090±70 # 09PLO-1 76 CURL-12594 plant macrofossils 0.3584±0.0009 -13.3 8245±20 9210±80 # #------------------ # Variables # # End Description/Documentation (lines begin with #) # Data lines follow (have no #) # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: material, error, units, anomaly, period, archive, detail, method, C or N for Character or Numeric data) # Data line format: tab-delimited text, variable short name as header age_calBP Age (calendar years BP), , ,cal BP, , , , ,N loi550C Loss-on-ignition at 550 degrees C (% by weight), , , %, , , , , N susc_si Magnetic susceptibility (SI units), , ,SI, , , , ,N age_calBP loi550C susc_si -59 2.7758 1.4 -20.745 2.46273 21.4 142.763 2.50597 34.5 303.086 2.16606 45.5 460.26 2.41514 42.5 614.318 1.63326 52.6 765.293 2.85714 53.7 913.22 3.21932 49.7 1058.13 5.14419 31.7 1200.06 6.5365 18.8 1339.05 6.51558 14.8 1475.11 6.43467 16.8 1608.3 6.46067 14.9 1738.65 6.50651 16.9 1866.18 7.64395 12.9 1990.93 7.41734 12 2112.94 9.97485 8.2 2232.23 11.4878 2.3 2348.85 10.4342 1.4 2462.83 10.254 0.4 2574.19 10.7172 0.5 2682.98 7.39796 0.6 2789.22 6.74897 0.7 2892.96 6.44346 1.7 2994.22 5.63287 1.8 3093.05 5.72049 1.9 3189.46 4.58811 1.9 3283.5 5.39972 1 3375.2 6.10442 2.1 3464.59 5.55224 2.2 3551.72 6.12864 1.2 3636.6 6.87984 1.3 3719.28 5.72391 1.4 3799.78 5.32213 1.5 3878.15 2.78734 1.5 3954.42 10.3567 0.6 4028.61 9.50226 0.7 4100.77 10.6478 0.7 4170.93 9.84848 0.8 4239.12 9.16149 -0.1 4305.37 12.4673 -0.1 4369.72 13.2765 0.1 4432.21 13.0952 0.2 4492.86 13.6033 0.2 4551.71 13.1742 0.3 4608.79 16.3177 0.3 4664.15 12.9711 0.3 4717.8 13.6719 0.4 4769.79 12.3391 0.4 4820.15 13.2363 0.5 4868.9 12.1655 0.5 4916.1 20.1962 0.5 4961.77 14.5103 0.6 5005.94 15.68 0.6 5048.65 18.4925 0.7 5089.92 15.5642 -0.3 5129.81 17.2635 0.8 5168.33 13.3628 0.8 5205.53 16.3138 -0.1 5241.43 16.4029 0.9 5276.07 15.774 1 5309.49 9.04589 -0.2 5341.71 16.3192 -0.3 5372.77 15.8897 -0.3 5402.71 16.7303 0.6 5431.56 14.4748 0.6 5459.35 17.3527 0.5 5486.12 14.1656 -0.6 5511.9 13.2562 0.4 5536.72 13.3913 0.3 5560.61 13.7201 0.3 5583.62 11.604 0.2 5605.78 11.648 0.1 5627.11 14.9042 0 5647.66 15.9218 0 5667.45 12.8529 -0.1 5686.52 16.3238 -0.2 5704.91 11.9609 -0.2 5722.64 9.47288 -0.3 5739.76 10.1022 0.6 5756.29 9.4123 1.2 5772.27 8.76911 1.2 5787.73 7.73263 1.1 5802.71 7.39507 1.1 5817.24 6.65951 1.9 5831.35 6.67624 1.9 5845.08 7.21003 1.8 5858.46 8.0348 0.8 5871.52 8.23723 0.7 5884.31 6.46516 1.7 5896.85 5.99284 2.7 5909.17 5.53483 2.6 5921.31 6.13615 1.6 5933.31 6.90834 2.5 5945.19 10.8411 1.5 5957 8.5504 1.4 5968.76 7.75038 1.4 5980.51 6.79365 2.4 5992.28 7.00086 2.3 6004.11 6.90979 1.3 6016.03 6.67135 1.2 6028.07 6.51515 2.2 6040.27 6.76893 2.2 6052.66 6.88073 2.1 6065.28 8.14183 3 6078.16 8.30691 2.8 6091.32 8.77193 1.7 6104.82 7.53475 1.6 6118.67 7.05253 2.5 6132.92 7.66129 1.5 6147.6 7.20659 2.4 6162.73 6.82594 1.3 6178.36 5.19288 2.2 6194.52 6.21951 2.1 6211.25 6.75195 2.1 6228.57 8.01282 2 6246.52 9.56734 1.9 6265.13 8.62553 1.8 6284.44 10.2056 1.7 6304.48 8.34813 1.6 6325.29 10.119 0.6 6346.9 4.14594 0.5 6369.33 9.04335 1.4 6392.64 6.20884 1.3 6416.84 6.26382 1.2 6441.98 4.36113 1.1 6468.09 4.12574 1.7 6495.2 3.34483 1.6 6523.34 3.37349 3.5 6552.55 7.76371 3.4 6582.86 4.27835 3.3 6614.32 8.42491 1.2 6646.94 6.89001 2.1 6680.76 5.95295 2 6715.82 5.76428 1.9 6752.15 9.89137 2.3 6789.79 6.52529 2.1 6828.77 3.38295 2.8 6869.12 2.47934 2.7 6910.87 1.45096 4.6 6954.07 1.72771 4.5 6998.74 2.06068 6.4 7044.92 2.17628 8.2 7092.63 0.92688 9.1 7141.93 1.27782 13 7192.83 1.30246 13.9 7245.38 1.57642 12.6 7299.6 0.884467 12.4 7355.53 1.0607 13.2 7413.2 1.05314 15.1 7472.65 1.10619 14.9