# Antarctic Ice Cores 160KYr Methane Isotope Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # 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: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:14651 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/vostok/vostok2013d13ch4.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Ice Cores #-------------------- # Contribution_Date # Date: 2013-06-10 #-------------------- # Title # Study_Name: Antarctic Ice Cores 160KYr Methane Isotope Data #-------------------- # Investigators # Investigators: Möller, L.; Sowers, T.A.; Bock, M.; Spahni, R.; Behrens, M.; Schmitt, J.; Miller, H.; Fischer, H. #-------------------- # Description_and_Notes # Description: Carbon and hydrogen isotopic data (d13C and dD) of atmospheric methane from the EPICA Dronning Maud Land and Vostok ice cores. # # We reconstructed atmospheric d13CH4 records using wet extraction techniques and continuous flow gas # chromatography combustion isotope ratio mass spectrometry (GC/C/IRMS) measurements performed on ice core # material from both the European Project for Ice Coring in Antarctica (EPICA) core from Dronning Maud Land # (EDML) and the Vostok cores. At the Alfred Wegener Institute (AWI) we analyzed 151 samples from the EDML core # (including 32 replicates, reproducibility of 0.2 , 1s) to construct a high resolution record between 20 kyr and 75 kyr BP # (1.000 years before present, present referring to 1950 AD) with an average temporal resolution of better than one # sample every 500 years. The period covering the two most pronounced climatic excursions in the Greenland # temperature record during MIS 3 (DO events 7 and 8) were sampled with a resolution of ~200 years. A # complementary record of 79 samples of Vostok ice core material was measured at the Pennsylvania State University # (PSU) covering a time period from 50 kyr to 160 kyr BP with an analytical uncertainty of 0.3 (1s), equivalent to an # average temporal resolution of 1660 years. # The two records were corrected for an instrumental interference from atmospheric krypton, for gravitational settling in # the firn, and a minor inter-laboratory offset of 0.14 . # All d13C values are reported versus Vienna PeeDee Belemnite (VPDB). # We further analyzed 20 samples of EDML ice for dD(CH4) with an external precision of about 2.5 (1s). The # measurements were performed at the University of Bern using a purge and trap extraction coupled to a gas # chromatography pyrolysis isotope ratio mass spectrometer (GC/P/IRMS) and cover the MIS 5/4 transition with an # average resolution of 1.5 kyr in between 54 and 85 kyr BP. The dD(CH4) values are reported with respect to # the international Vienna Standard Mean Ocean Water (VSMOW) scale. # # #-------------------- # Publication # Authors: Lars Möller, Todd Sowers, Michael Bock, Renato Spahni, Melanie Behrens, Jochen Schmitt, Heinrich Miller, and Hubertus Fischer # Published_Date_or_Year: 2013-08-25 # Published_Title: Independent variations of CH4 emissions and isotopic composition over the past 160,000 years # Journal_Name: Nature Geoscience # Volume: # Edition: # Issue: # Pages: # DOI: 10.1038/ngeo1922 # Online_Resource: # Full_Citation: # Abstract: During the last glacial cycle, greenhouse gas concentrations fluctuated on decadal and longer timescales. Concentrations of methane, as measured in polar ice cores, show a close connection with Northern Hemisphere temperature variability, but the contribution of the various methane sources and sinks to changes in concentration is still a matter of debate. Here we assess changes in methane cycling over the past 160,000 years by measurements of the carbon isotopic composition d13C of methane in Antarctic ice cores from Dronning Maud Land and Vostok. We find that variations in the d13C of methane are not generally correlated with changes in atmospheric methane concentration, but instead more closely correlated to atmospheric CO2 concentrations. We interpret this to reflect a climatic and CO2-related control on the isotopic signature of methane source material, such as ecosystem shifts in the seasonally inundated tropical wetlands that produce methane. In contrast, relatively stable d13C values occurred during intervals of large changes in the atmospheric loading of methane. We suggest that most methane sources - most notably tropical wetlands - must have responded simultaneously to climate changes across these periods. #------------------ # Publication # Authors: J. Chappellaz, J.M. Barnola, D. Raynaud, Y.S. Korotkevich, and C. Lorius # Published_Date_or_Year: 1990-05-10 # Published_Title: Ice-core record of atmospheric methane over the past 160,000 years # Journal_Name: Nature # Volume: 345 # Edition: 6271 # Issue: # Pages: 127-131 # DOI: 10.1038/345127a0 # Online_Resource: # Full_Citation: # Abstract: Methane measurements along the Vostok ice core reveal substantial changes over the past 160,000 years which are associated with climate fluctuations. These results point to changes in sources of methane and also show that methane has probably contributed, like carbon dioxide, to glacial-interglacial temperature changes. #------------------ # Publication # Authors: Benedicte Lemieux-Dudon, Eric Blayo, Jean-Robert Petit, Claire Waelbroeck, Anders Svensson, Catherine Ritz, Jean-Marc Barnola, Bianca Maria Narcisi, Frederic Parrenin # Published_Date_or_Year: 2010-01-01 # Published_Title: Consistent dating for Antarctic and Greenland ice cores # Journal_Name: Quaternary Science Reviews # Volume: 29 # Edition: # Issue: 1-2 # Pages: 8-20 # DOI: 10.1016/j.quascirev.2009.11.010 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0277379109003734 # Full_Citation: # Abstract: We are hereby presenting a new dating method based on inverse techniques, which aims at calculating consistent gas and ice chronologies for several ice cores. The proposed method yields new dating scenarios simultaneously for several cores by making a compromise between the chronological information brought by glaciological modeling (i.e., ice flow model, firn densification model, accumulation rate model), and by gas and ice stratigraphic constraints. This method enables us to gather widespread chronological information and to use regional or global markers (i.e., methane, volcanic sulfate, Beryllium-10, tephra layers, etc.) to link the core chronologies stratigraphically. Confidence intervals of the new dating scenarios can be calculated thanks to the probabilistic formulation of the new method, which takes into account both modeling and data uncertainties. We apply this method simultaneously to one Greenland (NGRIP) and three Antarctic (EPICA Dome C, EPICA Dronning Maud Land, and Vostok) ices cores, and refine existent chronologies. Our results show that consistent ice and gas chronologies can be derived for depth intervals that are well-constrained by relevant glaciological data. In particular, we propose new and consistent dating of the last deglaciation for Greenland and Antarctic ice and gas records. #------------------ # Publication # Authors: Dieter Lüthi, Martine Le Floch, Bernhard Bereiter, Thomas Blunier, Jean-Marc Barnola, Urs Siegenthaler, Dominique Raynaud, Jean Jouzel, Hubertus Fischer, Kenji Kawamura, and Thomas F. Stocker # Published_Date_or_Year: 2008-05-15 # Published_Title: High-resolution carbon dioxide concentration record 650,000-800,000 years before present # Journal_Name: Nature # Volume: 453 # Edition: # Issue: # Pages: 379-382 # DOI: 10.1038/nature06949 # Online_Resource: # Full_Citation: # Abstract: Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650,000 years. Here we present results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present. From previously published data and the present work, we find that atmospheric carbon dioxide is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present. Carbon dioxide levels are below 180 parts per million by volume (p.p.m.v.) for a period of 3,000 yr during Marine Isotope Stage 16, possibly reflecting more pronounced oceanic carbon storage. We report the lowest carbon dioxide concentration measured in an ice core, which extends the pre-industrial range of carbon dioxide concentrations during the late Quaternary by about 10 p.p.m.v. to 172-300 p.p.m.v. #------------------ # Publication # Authors: J. Schmitt, B. Seth, M. Bock, C. van der Veen, L. Möller, C.J. Sapart, M. Prokopiou, T. Sowers, T. Röckmann, and H. Fischer # Published_Date_or_Year: # Published_Title: On the interference of 86Kr2+ during carbon isotope analysis of atmospheric methane using continuous flow combustion - isotope ratio mass spectrometry # Journal_Name: Atmospheric Measurement Techniques Discussions # Volume: 6 # Edition: # Issue: 1 # Pages: 1409-1460 # DOI: 10.5194/amtd-6-1409-2013 # Online_Resource: http://www.atmos-meas-tech-discuss.net/6/1409/2013/amtd-6-1409-2013.html # Full_Citation: # Abstract: Stable carbon isotope analysis of methane (d13C of CH4) on atmospheric samples is one key method to constrain the current and past atmospheric CH4 budget. A frequently applied measurement technique is gas chromatography isotope ratio mass spectrometry coupled to a combustion-preconcentration unit. This report shows that the atmospheric trace gas krypton can severely interfere during the mass spectrometric measurement leading to significant biases in d13C of CH4 if krypton is not sufficiently separated during the analysis. The effect comes about by the lateral tailing of the peak of doubly charged 86Kr in the neighbouring m/z, 44, 45, and 46 Faraday cups. Accordingly, the introduced bias is dependent on the chromatographic separation, the Kr to CH4 mixing ratio in the sample, the mass spectrometer source tuning as well as the detector configuration and can amount to up to several permil in d13C. Apart from technical solutions to avoid this interference we present correction routines to a posteriori remove the bias. #-------------------- # Funding_Agency # Funding_Agency_Name: European Research Council (ERC) # Grant: Advanced Grant MATRICs #------------------ # Funding_Agency # Funding_Agency_Name: Schweizerischer Nationalfonds # Grant: #------------------ # Funding_Agency # Funding_Agency_Name: Deutsche Forschungsgemeinschaft # Grant: #------------------ # Funding_Agency # Funding_Agency_Name: European Unions Seventh Framework programme (FP7/2007-2013) # Grant: 243908 #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: 09-44584, 09-68391 #------------------ # Site_Information # Site_Name: Vostok # Location: Antarctica # Country: # Northernmost_Latitude: -78.4667 # Southernmost_Latitude: -78.4667 # Easternmost_Longitude: 106.8 # Westernmost_Longitude: 106.8 # Elevation: 3623 m #------------------ # Data_Collection # Collection_Name: Vostokd13CH4 # Earliest_Year: 164013 # Most_Recent_Year: 49690 # Time_Unit: Cal Year BP # Core_Length: 2250 m # Notes: #------------------ # Chronology: # # Tie-points for the manual methane synchronization of Vostok ice core data to EDC ice core gas age scales in between DO event 21 and the Termination 2 # Column 1: tie point No. # Column 2: tie-point EDC depth (m) # Column 3: Gas Age (EDC3 gas age, years before 1950 AD), for Vostok interpolated from data in Luethi et al. 2008, doi:10.1038/nature06949 # Column 4: EDC CH4 (ppb), (see Loulergue et al. 2008, doi:10.1038/nature06950) # Column 5: tie-point Vostok depth (m) # Column 6: Vostok CH4 (ppb), (see Chappellaz et al. 1990, doi:10.1038/345127a0) # # tie-point EDC depth EDC3 age EDC CH4 Vostok depth Vostok CH4 # (m) years BP (ppb) (m) (ppb) # 1 1241.67 83627 500.7 1266.83 500.1 # 2 1367.89 95866 470.2 1440.34 470.0 # 3 1473.40 106781 510.1 1536.00 510.8 # 4 1543.59 115081 480.2 1635.97 480.4 # 5 1723.46 128871 559.9 1881.99 560.1 # # # # #---------------- # Variables # # Data variables follow (have no #) # 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) # Vostok carbon isotopic data of atmospheric methane (d13CH4 ) # Gas Age (EDC3 gas age) interpolated from data in Luethi et al. 2008, doi:10.1038/nature06949 # Corrected EDC3 Gas Age by manual methane synchronization in between 83.6  kyr BP and 128.9  kyr BP # Unified gas age interpolated back from EDC3 gas age (column 2) to EDC depth, then to the Antarctic unified age scale (see Lemieux-Dudon et al. 2010, doi:10.1016/j.quascirev.2009.11.010) # Unified EDC3 corrected gas age same as column 4, but with corrected EDC3 gas ages (column 3) # d13C Kr-dev (column 6) deviations due to mass spectrometer interference with atmospheric krypton (see Schmitt et al. 2013, doi:10.5194/amtd-6-1409-2013) interpolated from Vostok [CH4] data (see Chappellaz et al.,1990 doi:10.1038/345127a0) # d13CH4VPDBgrav (col 7) values corrected for gravitational settling in the firn column # d13CH4 (per mil) values (column 7) corrected for interpolated Kr deviation (column 6) # d13CH4 (per mil) values (column 8) corrected for an inter-laboratory offset AWI-PSU of 0.14 # ## depth_m depth, , , m, , , , ,N ## age_gas_calBP age gas, , , calendar years before present, , , , ,N ## age_gas_calBPcorr age gas corrected, , , calendar years before present, , , , manual methane synchronization,N ## age_gas_calBPunif age gas unified, , , calendar years before present, , , Antarctic unified age scale, ,N ## age_gas_calBPunifcorr age gas unified EDC3 corrected, , , calendar years before present, , , , ,N ## d13CVPDBKr-dev delta13C, , , per mil VPDB, , , deviations due to mass spectrometer interference with atmospheric krypton, ,N ## d13CH4VPDBgrav delta13C, CH4, , per mil VPDB, , , corrected for gravitational settling in the firn column, ,N ## d13CH4VPDBKr-corr delta13C, CH4, , per mil VPDB, , , corrected for interpolated Kr deviation, ,N ## d13CH4VPDBKr-AWI delta13C, CH4, , per mil VPDB, , , corrected for an inter-laboratory offset AWI-PSU of 0.14, ,N # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: depth_m age_gas_calBP age_gas_calBPcorr age_gas_calBPunif age_gas_calBPunifcorr d13CVPDBKr-dev d13CH4VPDBgrav d13CH4VPDBKr-corr d13CH4VPDBKr-AWI 800.0 49690.0 49690.0 48876.2 48876.2 0.50 -45.35 -45.85 -45.99 825.0 51636.6 51636.6 50718.6 50718.6 0.50 -46.88 -47.38 -47.52 851.0 53513.1 53513.1 52686.1 52686.1 0.49 -45.68 -46.17 -46.31 877.0 55328.5 55328.5 54414.0 54414.0 0.47 -45.46 -45.93 -46.07 901.0 57004.2 57004.2 56118.2 56118.2 0.51 -45.67 -46.18 -46.32 923.0 58428.2 58428.2 57565.9 57565.9 0.57 -45.07 -45.64 -45.78 944.0 59900.5 59900.5 58928.6 58928.6 0.59 -44.29 -44.88 -45.02 965.0 61372.7 61372.7 60319.5 60319.5 0.59 -44.67 -45.26 -45.40 988.0 63008.2 63008.2 61801.5 61801.5 0.59 -44.11 -44.70 -44.84 1009.0 64748.4 64748.4 63629.8 63629.8 0.57 -45.28 -45.85 -45.99 1033.0 66701.1 66701.1 65728.2 65728.2 0.57 -44.19 -44.76 -44.90 1057.0 68626.4 68626.4 67978.6 67978.6 0.54 -47.17 -47.71 -47.85 1081.0 70551.6 70551.6 70483.8 70483.8 0.56 -47.67 -48.23 -48.37 1105.0 72581.3 72581.3 72721.6 72721.6 0.54 -47.99 -48.53 -48.67 1160.0 76983.9 76983.9 77618.5 77618.5 0.56 -47.84 -48.40 -48.54 1190.0 79227.8 79227.8 80323.9 80323.9 0.48 -48.24 -48.72 -48.86 1219.0 81215.0 81215.0 82588.3 82588.3 0.43 -46.87 -47.30 -47.44 1246.0 82980.7 82980.7 84440.1 84440.1 0.43 -47.56 -47.99 -48.13 1271.0 84772.9 83921.5 86053.2 85293.8 0.50 -47.10 -47.60 -47.74 1297.0 86858.0 85755.4 88054.8 86949.3 0.58 -46.54 -47.12 -47.26 1324.0 89162.2 87659.8 90512.8 88850.3 0.56 -46.19 -46.75 -46.89 1350.0 91330.3 89493.6 92817.9 90882.3 0.54 -48.15 -48.69 -48.83 1377.0 93524.2 91398.0 95157.6 92886.8 0.58 -48.35 -48.93 -49.07 1404.0 95789.0 93302.4 97299.8 94931.9 0.60 -48.44 -49.04 -49.18 1433.0 98267.7 95347.9 99629.1 96925.5 0.54 -48.36 -48.90 -49.04 1462.0 100735.7 98337.1 101914.9 99697.0 0.47 -48.52 -48.99 -49.13 1512.0 103872.2 104042.4 104741.6 104908.4 0.43 -48.03 -48.46 -48.60 1535.0 105217.2 106666.8 106086.3 107432.9 0.46 -47.88 -48.34 -48.48 1558.0 106569.3 108607.4 107346.3 109107.0 0.54 -48.55 -49.09 -49.23 1581.0 108017.1 110517.0 108581.6 111132.7 0.52 -48.99 -49.51 -49.65 1606.0 110772.5 112592.6 111403.1 113387.9 0.54 -50.31 -50.85 -50.99 1634.0 113786.5 114917.4 114727.0 115996.2 0.52 -49.97 -50.49 -50.63 1663.2 116045.1 116607.1 117231.5 117841.0 0.48 -49.57 -50.05 -50.19 1693.0 118130.6 118277.4 119403.5 119541.8 0.45 -50.18 -50.63 -50.77 1725.0 120263.7 120071.0 121410.6 121223.5 0.44 -50.17 -50.61 -50.75 1757.0 122269.6 121864.7 123232.6 122852.4 0.42 -50.12 -50.54 -50.68 1767.4 122910.0 122447.6 123796.9 123391.4 0.42 -50.03 -50.45 -50.59 1791.0 124316.1 123770.4 124985.2 124527.3 0.42 -48.75 -49.17 -49.31 1826.5 126393.7 125760.2 126889.1 126264.8 0.40 -48.59 -48.99 -49.13 1843.2 127204.6 126696.3 127683.6 127191.4 0.38 -48.43 -48.81 -48.95 1849.1 127472.3 127027.0 127941.6 127520.2 0.38 -48.13 -48.51 -48.65 1879.4 128745.3 128725.3 129159.5 129139.8 0.40 -48.16 -48.56 -48.70 1895.2 129348.9 129348.9 129719.4 129719.4 0.46 -46.96 -47.42 -47.56 1909.2 130078.6 130078.6 130375.5 130375.5 0.48 -46.08 -46.56 -46.70 1912.2 130259.0 130259.0 130541.4 130541.4 0.48 -47.14 -47.62 -47.76 1930.2 131341.6 131341.6 131508.2 131508.2 0.53 -46.51 -47.04 -47.18 1945.2 132367.0 132367.0 132417.4 132417.4 0.56 -45.41 -45.97 -46.11 1954.9 133097.8 133097.8 132986.1 132986.1 0.57 -44.82 -45.39 -45.53 1978.2 134795.9 134795.9 134188.5 134188.5 0.68 -43.95 -44.63 -44.77 1993.9 136186.4 136186.4 135193.9 135193.9 0.66 -43.62 -44.28 -44.42 1996.2 136399.7 136399.7 135374.8 135374.8 0.65 -44.35 -45.00 -45.14 2002.7 137002.1 137002.1 135894.3 135894.3 0.68 -44.95 -45.63 -45.77 2017.8 138470.2 138470.2 137247.8 137247.8 0.77 -45.05 -45.82 -45.96 2018.8 138572.1 138572.1 137343.9 137343.9 0.77 -44.34 -45.11 -45.25 2033.8 140129.8 140129.8 138760.9 138760.9 0.75 -44.81 -45.56 -45.70 2051.0 142143.1 142143.1 140714.7 140714.7 0.70 -44.46 -45.16 -45.30 2084.0 146125.8 146125.8 144665.9 144665.9 0.69 -45.90 -46.59 -46.73 2099.3 147921.5 147921.5 146428.5 146428.5 0.63 -44.43 -45.06 -45.20 2113.3 149509.8 149509.8 147945.0 147945.0 0.61 -44.72 -45.33 -45.47 2114.9 149678.1 149678.1 148100.2 148100.2 0.62 -43.81 -44.43 -44.57 2129.2 151220.6 151220.6 149554.3 149554.3 0.62 -43.27 -43.89 -44.03 2145.0 153063.6 153063.6 151202.8 151202.8 0.63 -42.25 -42.88 -43.02 2162.3 155166.3 155166.3 153188.7 153188.7 0.63 -43.07 -43.70 -43.84 2177.0 156839.3 156839.3 154896.4 154896.4 0.61 -44.02 -44.63 -44.77 2191.0 158305.4 158305.4 156522.7 156522.7 0.64 -43.57 -44.21 -44.35 2206.0 159827.8 159827.8 158193.4 158193.4 0.63 -44.26 -44.89 -45.03 2220.0 161188.6 161188.6 159361.9 159361.9 0.61 -44.44 -45.05 -45.19 2235.0 162573.5 162573.5 160769.6 160769.6 0.58 -43.21 -43.79 -43.93 2250.0 164013.3 164013.3 162120.5 162120.5 0.55 -44.67 -45.22 -45.36