A Massive Canyon Was Just Discovered Under Greenland's Ice Sheet
http://www.businessinsider.com/massive-canyon-found-under-greenlands-ice-sheet-2013-8
One mile under Greenland's ice sheet lies a 460-mile long canyon that went unknown to scientists until now.
The discovery was several decades in the making as NASA and researchers from Germany and the United Kingdom used radar data collected by aircraft over thousands of miles to piece together the landscape.
The depth of the bedrock was determined by measuring the amount of time it took radio waves to travel through the ice and bounce back from the bedrock underneath, NASA explained in a statement. The longer it took, the deeper the bedrock.
The newly-discovered canyon is longer than the Grand Canyon, according to NASA. It is 2,600-feet deep in some places, which compares to segments of the Grand Canyon.
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