Melting Antarctic Glacier Could Flood Coastal Areas, Scientists Say

A melting Antarctic glacier could lead to the collapse of the West Antarctic Ice Sheet, causing global sea levels to rise as much as 20 feet, researchers said Thursday.

Satellite radar images between 1992 and 1996 of Pine Island glacier in West Antarctica showed the glacier is shrinking.

“It is important because it could lead to a collapse of the West Antarctic Ice Sheet,” said study leader Eric Rignot, a radar scientist at the Jet Propulsion Laboratory in Pasadena. “We are seeing a glacier melt in the heart of Antarctica.”

Antarctica has about 90% of the world’s glacial ice. Scientists say this data from remote and stormy West Antarctica could be the first real evidence that some of these massive glaciers might actually be retreating rapidly.

“The continuing retreat of Pine Island glacier could be a symptom of the [West Antarctic Ice Sheet] disintegration,” said Craig Lingle, a glaciologist at the University of Alaska in Fairbanks who is familiar with the study.

If the sheet did collapse, it would push sea levels up throughout the world, with regions near sea level experiencing more flooding and faster erosion, Lingle said.

Pine Island glacier is really a fast-moving ice stream, taking accumulated snow from the interior of the ice sheet and spitting it into the ocean in the form of ice, he said.

In the study, published in the journal Science, Rignot speculated that warmer ocean waters are causing the melting.

Richard Alley, a glaciologist at Penn State University, said if the glacier retreated too far it would allow too much ice to escape, causing a collapse of the shelf.

“It would make a hole in the side of the ice sheet and the remaining ice would drain through that hole,” he added. “This is the disaster scenario.”

“If world sea levels went up 6 meters [about 20 feet], there would be problems for all coastal areas,” Lingle said.

Alley agreed that the consequences of an ice shelf collapse would be severe. But he noted: “We are not saying it will probably happen, but it is possible, and if it does, it will affect a lot of people.”