Law Dome Ice Core 500 Year Lead Isotope and Barium Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Law Dome Ice Core 500 Year Lead Isotope and Barium Data LAST UPDATE: 8/2011 (Original receipt by WDC Paleo) CONTRIBUTORS: Vallelonga, P., K. Van de Velde, J.-P. Candelone, V.I. Morgan, C.F. Boutron, and K.J.R. Rosman. IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2011-100 WDC PALEO CONTRIBUTION SERIES CITATION: Vallelonga, P., et al. 2011. Law Dome Ice Core 500 Year Lead Isotope and Barium Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2011-100. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Vallelonga, P., K. Van de Velde, J.-P. Candelone, V.I. Morgan, C.F. Boutron, and K.J.R. Rosman. 2002. The lead pollution history of Law Dome, Antarctica, from isotopic measurements on ice cores: 1500 AD to 1989 AD. Earth and Planetary Science Letters, Vol. 204, Issues 1-2, pp. 291-306, 30 November 2002. doi:10.1016/S0012-821X(02)00983-4 ABSTRACT: Lead isotopic compositions and Pb and Ba concentrations have been measured in ice cores from Law Dome, East Antarctica, covering the past 6500 years. 'Natural' background concentrations of Pb (~0.4 pg/g) and Ba (~1.3 pg/g) are observed until 1884 AD, after which increased Pb concentrations and lowered 206Pb/207Pb ratios indicate the influence of anthropogenic Pb. The isotopic composition of 'natural' Pb varies within the range 206Pb/207Pb=1.20 - 1.25 and 208Pb/207Pb=2.46 - 2.50, with an average rock and soil dust Pb contribution of 8-12%. A major pollution event is observed at Law Dome between 1884 and 1908 AD, elevating the Pb concentration four-fold and changing 206Pb/207Pb ratios in the ice to ~1.12. Based on Pb isotopic systematics and Pb emission statistics, this is attributed to Pb mined at Broken Hill and smelted at Broken Hill and Port Pirie, Australia. Anthropogenic Pb inputs are at their greatest from ~1900 to ~1910 and from ~1960 to ~1980. During the 20th century, Ba concentrations are consistently higher than 'natural' levels and are attributed to increased dust production, suggesting the influence of climate change and/or changes in land coverage with vegetation. GEOGRAPHIC REGION: Antarctica PERIOD OF RECORD: 1500 - 1989 AD FUNDING SOURCES: Australian Research Council (A39938047), Australian Antarctic Science Advisory Committee, Glaciology Section (No. 1092). DESCRIPTION: Law Dome Antarctica ice core Pb and Ba concentrations, and Pb isotope ratios, for the period 1500-1989 CE. DSS-W20k firn/ice core: 66°46'27"S, 112°21'26.1"E, 1200 m asl DSS and DSS99 ice cores: 66°46'11"S, 112°48'25"E, 1370 m asl DATA: Lead and Ba concentrations and Pb isotopic compositions measured in Law Dome ice cores. Column 1: Sample designation Column 2: Sample date [years CE] Column 3: Lead 206/Lead 207 (206Pb/207Pb) Column 4: Lead 206/Lead 207 (206Pb/207Pb) Error Column 5: Lead 208/Lead 207 (208Pb/207Pb) Column 6: Lead 208/Lead 207 (208Pb/207Pb) Error Column 7: Lead 206/Lead 204 (206Pb/204Pb) Column 8: Lead 206/Lead 204 (206Pb/204Pb) Error Column 9: Lead concentration (Pb conc.) [pg/g] Column 10: Barium concentration (Ba conc.) [pg/g] Column 11: Pb/Ba ratio [g/g at.wt.] Sample Date 206Pb/207Pb ±   208Pb/207Pb ±   206Pb/204Pb ±   PbConc. BaConc. Pb/Ba DSS-W2k 9 1989 1.1 0.002 2.369 0.006 17.7 0.2 7 4.68 1.5 DSS-W2k 17 1983 1.168 0.007 2.428 0.016 18.1 0.7 0.88 1.72 0.51 DSS-W20k 7 1977 1.163 0.006 2.422 0.012 18.1 0.2 1.6 1.22 1.31 DSS-W20k 9 1971 1.163 0.004 2.425 0.009 18.2 0.5 2.46 2.42 1.01 DSS-W20k 10 1967 1.145 0.005 2.408 0.014 17.6 0.3 1.33 2.02 0.66 DSS-W20k 11 1964 1.15 0.005 2.408 0.01 17.3 1.5 1.51 3.47 0.43 DSS-W20k 12 1960 1.165 0.005 2.429 0.006 18.3 0.2 2.89 2.98 0.97 DSS-W20k 13 1956 1.144 0.007 2.404 0.011 17.9 0.4 1.27 3.75 0.34 DSS-W20k 15 1948 1.171 0.005 2.441 0.008 18.2 0.2 1.08 1.84 0.59 DSS-W20k 16 1942 1.167 0.006 2.432 0.013 18.3 0.4 0.59 2.01 0.29 DSS99 36 1939 1.179 0.005 2.449 0.01 18.4 0.3 0.79 1.08 0.73 DSS-W20k 18 1933 1.179 0.006 2.436 0.03 17.8 1.5 1.72 2.16 0.8 DSS99 40 1932 1.178 0.005 2.44 0.016 17.8 0.5 1.1 6.67 0.16 DSS99 51 1919 1.181 0.004 2.449 0.005 18.5 0.4 1.24 1.11 1.11 DSS99 60 1908 1.167 0.006 2.445 0.008 18.5 0.7 1.69 1.72 0.98 DSS99 68 1898 1.123 0.006 2.395 0.006 17.5 0.2 1.42 1.49 0.95 DSS99 75 1890 1.179 0.007 2.425 0.02 17.4 1.1 0.63 2.03 0.31 DSS99 79 1884 1.205 0.01 2.473 0.012 18.4 0.8 0.45 1.1 0.41 DSS99 84 1877 1.224 0.006 2.491 0.015 19.1 0.3 0.41 0.67 0.62 DSS99 95 1860 1.234 0.007 2.487 0.008 19 0.6 0.32 0.9 0.36 DSS-W20k 35 1858 1.214 0.019 2.482 0.018 18.9 2.4 0.21 1.02 0.21 DSS99 103 1852 1.231 0.005 2.482 0.015 19.2 0.5 0.28 1.02 0.27 DSS-W20k 41 1831 1.252 0.002 2.498 0.009 19.9 0.4 0.45 0.9 0.5 DSS-W20k 46 1807 1.224 0.019 2.488 0.027 19.1 2.2 0.36 1.98 0.18 DSS-W20k 50 1790 1.235 0.006 2.487 0.022 18.5 1.3 0.47 1.5 0.31 DSS-W20k 55 1767 1.201 0.01 2.471 0.029 19 0.5 0.36 1.81 0.2 DSS-W20k 62 1729 1.235 0.013 2.483 0.024 19.2 1.7 0.27 0.75 0.36 DSS-W20k 70 1692 1.232 0.007 2.496 0.012 19.9 0.6 0.33 1.4 0.24 BHD 132 1650 1.239 0.007 2.489 0.027 18.9 1.6 0.48 1.37 0.35 DSS 218 1605 1.233 0.006 2.481 0.025 19.1 1.3 0.33 1.3 0.25 DSS 257 1530 1.242 0.005 2.5 0.009 18.9 0.5 0.3 0.68 0.44 DSS 790 68AD 1.245 0.007 2.482 0.012 19.1 0.4 0.42 1.83 0.23 DSS 1129 4500BC 1.211 0.008 2.456 0.016 19.1 1.2 0.31 3.21 0.09 Uncertainties in the dating of samples from DSS, DSS99, DSS-W2k and BHD are ±<1 year, while dating of DSS-W20k cores are generally <±5 years. Uncertainties in the isotope ratios are 95% confidence intervals. This includes allowance for bias based upon measurements of NIST SRM 981. 95% confidence intervals on concentrations are ±15%.