Carbon Dating of Polar Ice Cores

作为格陵兰冰盖项目的一部分，这项调查将对相对较小（几公斤）的极地冰芯样本中捕获的大气气体进行碳-14测定。该技术将把冰放在真空系统中，并将冰升华到零下80摄氏度的冷阱表面。这个过程释放的气体将通过一个保持在液氮温度下的多通道捕集器，这将使所有的二氧化碳都能被回收。这样得到的CO2样品将被精确地稀释并转化为石墨靶，用加速器质谱法测定14C。除CO2（和N2O）以外的大气气体将被捕获在分子筛上，并可用于与北半球古气候学有关的其他研究。

As part of the Greenland Ice Sheet Project, this investigation will carbon-14 date atmospheric gases trapped in relatively small (a few kg) samples of polar ice cores. The technique would be to place the ice in a vacuum system and the sublime the ice onto the surface of a -80C degrees cold trap. The gas released by this procedure would be passed through a multipass trap held at liquid- nitrogen temperature, which would enable all the carbon dioxide to be recovered. The CO2 sample so obtained would be accurately diluted and converted into a graphite target for 14C determination by accelerator mass spectrometry. The atmospheric gases other than CO2 (and N2O) would be trapped on a molecular sieve and be available for other studies related to the paleoclimatology of the northern hemisphere.