# Northeast Greenland Ice Stream (NEGIS) 2012 Ice Core Chemistry and Density #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 2.0 # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/20427 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/negis2012dens.txt # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Ice Cores # # Parameter_Keywords: chemistry, physical properties, accumulation #-------------------- # Contribution_Date # Date: 2016-08-11 #-------------------- # Title # Study_Name: Northeast Greenland Ice Stream (NEGIS) 2012 Ice Core Chemistry and Density #-------------------- # Investigators # Investigators: Vallelonga, P. #-------------------- # Description_and_Notes # Description: CFA chemistry, density, accumulation, and annual layer thickness data produced from NEGIS 2012 ice core. # Provided Keywords: ice core, accumulation, density, annual layer, ammonium, conductivity, Greenland, volcanoes, sea salt, sodium, dust, ice stream #-------------------- # Publication # Authors: P. Vallelonga, K. Christianson, R.B. Alley, S. Anandakrishnan, J.E.M. Christian, D. Dahl-Jensen, V. Gkinis, C. Holme, R.W. Jacobel, N.B. Karlsson, B.A. Keisling, S. Kipfstuhl, H.A. Kjær, M.E.L. Kristensen, A. Muto, L.E. Peters, T. Popp, K.L. Riverman, A.M. Svensson, C. Tibuleac, B.M. Vinther, Y. Weng, and M. Winstrup # Published_Date_or_Year: 2014-07-22 # Published_Title: Initial results from geophysical surveys and shallow coring of the Northeast Greenland Ice Stream (NEGIS) # Journal_Name: The Cryosphere # Volume: 8 # Edition: # Issue: 4 # Pages: 1275-1287 # Report_Number: # DOI: 10.5194/tc-8-1275-2014 # Online_Resource: http://www.the-cryosphere.net/8/1275/2014/ # Full_Citation: # Abstract: The Northeast Greenland Ice Stream (NEGIS) is the sole interior Greenlandic ice stream. Fast flow initiates near the summit dome, and the ice stream terminates approximately 1000 km downstream in three large outlet glaciers that calve into the Greenland Sea. To better understand this important system, in the summer of 2012 we drilled a 67 m firn core and conducted ground-based radio-echo sounding (RES) and active-source seismic surveys at a site approximately 150 km downstream from the onset of streaming flow (NEGIS firn core, 75 37.61'N, 35 56.49'W). The site is representative of the upper part of the ice stream, while also being in a crevasse-free area for safe surface operations. Annual cycles were observed for insoluble dust, sodium and ammonium concentrations and for electrolytic conductivity, allowing a seasonally resolved chronology covering the past 400 yr. Annual layer thicknesses averaged 0.11 m ice equivalent (i.e.) for the period 1607-2011, although accumulation varied between 0.08 and 0.14 m i.e., likely due to flow-related changes in surface topography. Tracing of RES layers from the NGRIP (North Greenland Ice Core Project) ice core site shows that the ice at NEGIS preserves a climatic record of at least the past 51 kyr. We demonstrate that deep ice core drilling in this location can provide a reliable Holocene and late-glacial climate record, as well as helping to constrain the past dynamics and ice-lithosphere interactions of the Greenland Ice Sheet. #------------------ # Funding_Agency # Funding_Agency_Name: Danish National Research Foundation # Grant: Centre for Ice and Climate #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OPP 0424589 #------------------ # Funding_Agency # Funding_Agency_Name: US NASA Operation IceBridge # Grant: NNX13AD53A #------------------ # Site_Information # Site_Name: Northeast Greenland Ice Stream (NEGIS) # Location: North America>Greenland # Country: # Northernmost_Latitude: 75.623 # Southernmost_Latitude: 75.623 # Easternmost_Longitude: -35.96 # Westernmost_Longitude: -35.96 # Elevation: 2702 m #------------------ # Data_Collection # Collection_Name: NEGIS2012dens # Earliest_Year: 343 # Most_Recent_Year: -62 # Time_Unit: Cal. year BP # Core_Length: 66.55 m # Notes: #------------------ # Chronology_Information # Chronology: Chronology established by annual layer counting with volcano tiepoints, as described in the reference. # See full age model in file negis2012age.txt # #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ## depth_m depth, , , m, , , , ,N ## dens density, ice, , g/cm3, , ice cores, , ,N ## thick_m Annual Layer Thickness, ice, , m, , ice cores, , ,N ## accum Annual snow accumulation (ice equivalent), , , m ie/yr, , ice cores, , ,N # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # depth_m dens thick_m accum 1.38 0.2519 0.5455 0.1374 1.93 0.2709 0.3827 0.1037 2.48 0.3208 0.3648 0.1170 3.03 0.3444 0.3999 0.1377 3.58 0.3269 0.4200 0.1373 4.13 0.3406 0.3029 0.1032 4.68 0.3459 0.3589 0.1241 5.23 0.3569 0.3698 0.1320 5.78 0.3775 0.3484 0.1315 6.33 0.3972 0.3699 0.1469 6.88 0.4128 0.4193 0.1731 7.43 0.4363 0.2983 0.1302 7.98 0.4312 0.2536 0.1093 8.53 0.4410 0.2297 0.1013 9.08 0.4490 0.2762 0.1240 9.63 0.4520 0.2940 0.1329 10.18 0.4825 0.3007 0.1451 10.73 0.4785 0.2390 0.1143 11.28 0.4832 0.2181 0.1054 11.83 0.4874 0.1900 0.0926 12.38 0.5000 0.2586 0.1293 12.93 0.4973 0.1975 0.0982 13.48 0.4897 0.1915 0.0938 14.03 0.5057 0.2007 0.1015 14.58 0.5179 0.2130 0.1103 15.13 0.5175 0.1950 0.1009 15.68 0.5255 0.1319 0.0693 16.23 0.5347 0.2605 0.1393 16.78 0.5373 0.2192 0.1178 17.33 0.5289 0.1645 0.0870 17.88 0.5441 0.1190 0.0647 18.43 0.5582 0.1270 0.0709 18.98 0.5574 0.1480 0.0825 19.53 0.5607 0.1577 0.0884 20.08 0.5684 0.2365 0.1344 20.63 0.5670 0.1210 0.0686 21.18 0.5781 0.1343 0.0776 21.73 0.5883 0.1892 0.1113 22.28 0.5913 0.1416 0.0837 22.83 0.5978 0.1581 0.0945 23.38 0.5966 0.1517 0.0905 23.93 0.6158 0.1966 0.1211 24.48 0.5961 0.1733 0.1033 25.03 0.6164 0.1475 0.0909 25.58 0.6187 0.2117 0.1310 26.13 0.6134 0.1924 0.1180 26.68 0.6195 0.1500 0.0929 27.23 0.6328 0.1393 0.0881 27.78 0.6320 0.1671 0.1056 28.33 0.6343 0.1877 0.1190 28.88 0.6520 0.1891 0.1233 29.43 0.6376 0.1536 0.0979 29.98 0.6564 0.1486 0.0975 30.53 0.6529 0.2000 0.1306 31.08 0.6594 0.1868 0.1232 31.63 0.6598 0.1893 0.1249 32.18 0.6575 0.1382 0.0909 32.73 0.6682 0.1837 0.1227 33.28 0.6731 0.2261 0.1522 33.83 0.6788 0.1479 0.1004 34.38 0.6788 0.1675 0.1137 34.93 0.6967 0.1852 0.1290 35.48 0.6880 0.1964 0.1351 36.03 0.6887 0.1707 0.1175 36.58 0.6982 0.1985 0.1386 37.13 0.6895 0.2066 0.1425 37.68 0.7131 0.1520 0.1084 38.23 0.6975 0.1535 0.1071 38.78 0.7112 0.1779 0.1265 39.33 0.7066 0.1704 0.1204 39.88 0.7043 0.2063 0.1453 40.43 0.7138 0.1741 0.1243 40.98 0.6990 0.1526 0.1067 41.53 0.7218 0.2040 0.1472 42.08 0.7165 0.1819 0.1303 42.63 0.7309 0.1510 0.1104 43.18 0.7386 0.1816 0.1341 43.73 0.7275 0.1739 0.1265 44.28 0.7317 0.1584 0.1159 44.83 0.7328 0.1742 0.1277 45.38 0.7386 0.1559 0.1151 45.93 0.7264 0.1529 0.1110 46.48 0.7515 0.1115 0.0838 47.03 0.7477 0.1279 0.0956 47.58 0.7454 0.1286 0.0959 48.13 0.7617 0.1124 0.0856 48.68 0.7417 0.1179 0.0875 49.23 0.7591 0.1341 0.1018 49.78 0.7530 0.1586 0.1194 50.33 0.7621 0.1170 0.0891 50.88 0.7694 0.0921 0.0709 51.43 0.7667 0.1526 0.1170 51.98 0.7827 0.0860 0.0673 52.53 0.7701 0.1293 0.0996 53.08 0.7869 0.0933 0.0734 53.63 0.7766 0.0942 0.0732 54.18 0.7899 0.1089 0.0860 54.73 0.7941 0.1243 0.0987 55.28 0.7911 0.1480 0.1171 55.83 0.7918 0.1312 0.1039 56.38 0.7960 0.1176 0.0936 56.93 0.7933 0.1051 0.0834 57.48 0.7972 0.1161 0.0926 58.03 0.8040 0.1261 0.1013 58.58 0.7975 0.1209 0.0964 59.13 0.8101 0.0987 0.0799 59.68 0.8078 0.1046 0.0845 60.23 0.8054 0.1288 0.1037 60.78 0.8190 0.1506 0.1234 61.33 0.8166 0.1198 0.0979 61.88 0.8193 0.1275 0.1044 62.43 0.8118 0.1595 0.1295 62.98 0.8181 0.1344 0.1100 63.53 0.8395 0.1289 0.1082 64.08 0.8132 0.1524 0.1240 64.63 0.8265 0.1067 0.0882 65.18 0.8230 0.1328 0.1093 65.73 0.8234 0.1293 0.1065 66.28 0.8348 0.1274 0.1063