Hollow coring drills are used to extract ice cores that can analyze the past atmosphere. Scientists have now documented carbon dioxide in the atmosphere between 23,000 and 9,000 years ago, based on data from an 11,000-foot hole in Antarctica.
http://feeds.sciencedaily.com/~r/sciencedaily/~3/kzo57y9cWm8/141030163048.htm
They know the drill: Leading the league in boring through ice sheets
30 October 2014
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