Sudden Acceleration in Ice Loss of "Stable" Southern Antarctic Peninsula, New Study Finds

Scientists have observed a sudden increase in ice loss on the Southern Antarctic Peninsula. The region was previously thought to be a stable region of Antarctica.

Researchers measured the elevation of the Antarctic sheet made by a suite of satellites and found that the Southern Antarctic Peninsula shows no signs of change up to 2009. But in 2009, multiple glaciers along a vast coastal expanse, measuring some 750km in length, suddenly started to shed ice into the ocean at a nearly constant rate of 60 cubic km, or about 55 trillion liters of water, each year, researchers wrote in the observation.

"The fact that so many glaciers in such a large region suddenly started to lose ice came as a surprise to us," said Dr Bert Wouters, a Marie Curie Fellow at the University of Bristol in a press release. "It shows a very fast response of the ice sheet: in just a few years the dynamic regime completely shifted."

Researchers believe that the rapid ice loss is due to warming oceans and note changes in snowfall and oceans.

"Many of the glaciers in the region feed into ice shelves that float on the surface of the ocean," Wouters explained. "They act as a buttress to the ice resting on bedrock inland, slowing down the flow of the glaciers into the ocean. The westerly winds that encircle Antarctica have become more vigorous in recent decades, in response to climate warming and ozone depletion. The stronger winds push warm waters from the Southern Ocean poleward, where they eat away at the glaciers and floating ice shelves from below."

"It appears that sometime around 2009, the ice shelf thinning and the subsurface melting of the glaciers passed a critical threshold which triggered the sudden ice loss," Wouters added. "However, compared to other regions in Antarctica, the Southern Peninsula is rather understudied, exactly because it did not show any changes in the past, ironically."

The observations were published in the latest edition of Science.