Deep beneath the surface of Greenland's ice sheet lies a chasm half a mile deep and longer than the Grand Canyon. According to a paper published in Science , radar data from NASA's IceBridge project — which measures changes in polar ice from aircraft — has revealed the existence of the hitherto-unknown canyon. Part of IceBridge's mission is to measure ice thickness, using frequencies that can bounce through ice to the bedrock beneath. When data from IceBridge and previous studies was put together, it revealed a canyon 460 miles long and 2,600 feet deep; by comparison, the Grand Canyon is 277 miles long, its deepest point 6,000 feet below the rim.
The newly discovered canyon is thought to have formed before ice covered Greenland, and...
via The Verge - All Posts http://www.theverge.com/2013/8/29/4673328/scientists-find-new-canyon-under-greenland-ice
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