As warm ocean water rises up to melt them, glaciers around the Amundsen Sea are losing half a Mount Everest a year.
A second study, published Thursday in the journal Science, helps explain the accelerating ice melt: Warm ocean water is melting the floating ice shelves that hold back the glaciers.
The two new pieces of research come as officials of the World Meteorological Organization announced Wednesday that 2014 is on track to be the warmest year on record.
Scientists have long worried that the West Antarctic ice sheet is a place where climate change might tip toward catastrophe. The ice sheet holds enough water to raise sea level by 16 feet (5 meters). The region along the Amundsen Sea is the sheet’s soft underbelly, where the ice is most vulnerable. (See “Rising Seas” in National Geographic magazine.)
Earlier this year, researchers at the University of California, Irvine and NASA’s Jet Propulsion Laboratory reported that the glaciers flowing into the Amundsen Sea—notably the Pine Island and Thwaites Glaciers—were already doomed to collapse, and at the current rate of melting would be gone in 200 years.