论文信息 - Gas Extraction From Polar Ice Cores: A Critical Issue For Studying The Evolution of Atmospheric CO2 and Ice-Sheet Surface Elevation

Gas Extraction From Polar Ice Cores: A Critical Issue For Studying The Evolution of Atmospheric CO2 and Ice-Sheet Surface Elevation

The measurement of gases enclosed in polar ice cores provides valuable Information concerning the history of the ice sheets and their environment. The extraction of gases from ice is a critical step in the experimental procedure. We found that the most efficient methods of gas extraction for 20 to 50 g samples were ice melting and controlled refreezing of the melt water for the total gas content and ice crushing far the CO2 content. These two experimental methods are described in detail. It is shown, in particular, that ice is easily contaminated by carbonate dust during sample preparation. This contamination introduces an excess of CO2 when gases are extracted using a procedure involving ice melting.

[1] D. Raynaud,et al. Air Content Of The Byrd Core And Past Changes In The West Antarctic Ice Sheet , 1982, Annals of Glaciology.

[2] M. Legrand,et al. Polar ice evidence that atmospheric CO2 20,000 yr BP was 50% of present , 1980, Nature.

[3] H. Oeschger,et al. Information on the CO2 Cycle from Ice Core Studies , 1980, Radiocarbon.

[4] D. Raynaud,et al. Total gas content and surface elevation of polar ice sheets , 1979, Nature.

[5] D. Raynaud,et al. Ice Flow Along an I.A.G.P. Flow Line and Interpretation of Data From an Ice Core in Terre Adélie, Antarctica , 1979, Journal of Glaciology.

[6] A. T. Wilson,et al. Chemical composition of south polar snow , 1965 .