DOOMSDAY GLACIER
Study: Shelf holding back key Antarctic glacier could break up in 5 years

Pictured is the Pine Island Glacier in the West Antarctic Ice Sheet in October 2011. Scientists said Monday an ice shelf holding another Antarctic glacier, the Thwaites Glacier, could break up within five years. File Photo courtesy of NASA | License Photo

Dec. 13 (UPI) -- Scientists warned Monday that an ice shelf holding a crucial Antarctic glacier could break up within the next five years, potentially greatly increasing the rate of sea level rise.

A report presented at the annual meeting of the American Geophysical Union in New Orleans said a series of newly discovered weaknesses is causing the Thwaites Eastern Ice Shelf, which buttresses one-third of the Florida-sized Thwaites Glacier, to "lose its grip" on a submarine shoal pinning it in place.

Through the use of satellite data, ground-penetrating radar and GPS measurements, the researchers found worrisome cracks in the shelf spreading into its central area at rates as high as 2 kilometers per year, spurred by a warming ocean.

At that rate, they determined the "final collapse of Thwaites Glacier's last remaining ice shelf may be initiated by intersection of rifts with hidden basal crevasse zones within as little as five years."

The Thwaites Eastern Ice Shelf is the "floating terminus" of the massive Thwaites Glacier, sometimes referred to as the Doomsday Glacier, one of the fastest moving glaciers in Antarctica which already is contributing as much as 4% of global sea level rise.

The shelf acts as a dam to slow the flow of ice off the continent into the ocean, and if it breaks apart, the authors warned, the Thwaites Glacier will ramp up its current contribution to sea level rise by as much as 25%.

Scientists have warned that a total collapse of the Thwaites Glacier could result in several feet of sea level rise that would endanger millions of people in coastal areas. It also acts as a linchpin on the rest of the Antarctic ice sheet, which contains enough ice to cause another 10 feet to 13 feet of global sea level rise.

"Thwaites is the widest glacier in the world," said Ted Scambos, a senior research scientist at the University of Colorado's Cooperative Institute for Research in Environmental Sciences.

"It's doubled its outflow speed within the last 30 years, and the glacier in its entirety holds enough water to raise sea level by over two feet. And it could lead to even more sea-level rise, up to 10 feet, if it draws the surrounding glaciers with it."