An 18-mile crack in an Antarctic ice-shelf has been discovered by an airborne polar-ice surveying program run by NASA.
The crack, located in the Pine Island Glacier, is 165 to 195 feet (50 to 60 meters) deep and about 260 feet (79 meters) wide along most of the rift, stretching to 820 feet (250 meters) wide at its widest point, CBS News reported.
Scientists estimate the crack started forming between late September and early October, CBS News reported. When the crack completes its run, the resulting iceberg that breaks off the glacier will be the size of New York City, NASA officials said. The 340-square-mile iceberg should break away by the end of 2011 or early in 2012, BBC News reported.
NASA researchers said this latest iceberg-in-the-making is part of a natural cycle seen every 10 years or so on the Pine Island Glacier, BBC News reported.
“We are actually now witnessing how it happens and it's very exciting for us," IceBridge project scientist Michael Studinger of NASA's Goddard Space Flight Center in Greenbelt, Md., told CBS News. "It's part of a natural process, but it's pretty exciting to be here and actually observe it while it happens."
According to MSNBC:
Glaciers naturally give birth to icebergs, but scientists are concerned that warming temperatures might be destabilizing those in Antarctica and Greenland by eroding the ice shelves floating on water that hold them back up against the mainland.
Without the ice shelves, those glaciers could flow much faster into the ocean, raising sea levels.
While the new iceberg will be big, it won’t break any records, MSNBC reported. The biggest iceberg observed to date was a 12,000-square-mile chunk of ice seen in 1956.
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