"A major feature of the Earth has escaped notice — until now. Scientists Thursday that they've discovered a vast canyon, twice as long as the Grand Canyon. It carves a deep scar from the center of the world's largest island out to the coast. And, oh one more detail: It's buried beneath as much as 2 miles of ice. Yes, we're talking about icy Greenland."
Richard Harris reports for NPR's All Things Considered August 29, 2013.