Pat Shingleton: "A Secret - Under the Ice..."
It was always believed that Greenland's ice sheet rested on flat bedrock. A recent study, published in "Science" reveals that the mile-and-a-half-thick sheet of ice, covers a canyon that is 465 miles long. NASA's Operation Icebridge is a polar ice monitoring mission that uses ice-penetrating radar and discovered that the canyon stretches from the center of Greenland to the northwest coast. The canyon is a half-mile deep, more than six miles wide and channels meltwater from Greenland's interior to the ocean. Researchers believe the canyon helps to "lubricate" the movement of the massive ice sheet toward the coast. Additional research notes that channels of rolling sea water create cavities that cause iceberg collapses, such as in 2010.