Study: Ice Loss Has Accelerated in Antarctica
According to new research published in the Proceedings of the National Academy of Sciences, Antarctica is losing ice mass six times faster than it did in the 1980s. Researchers from the University of California at Irvine, NASA’s Jet Propulsion Laboratory and Utrecht University also found that the accelerated melting caused sea levels to rise more than half an inch during that time.
“That’s just the tip of the iceberg, so to speak,” said lead author Eric Rignot of UC-Irvine. “As the Antarctic ice sheet continues to melt away, we expect multi-meter sea level rise from Antarctica in the coming centuries.”
Much of the recent focus on Antarctica's shrinking glaciers has centered on its western region - in particular, on West Antarctica's Pine Island, Thwaites, Haynes, Smith, Pope and Kohler glaciers, which all discharge ice into a vast bay known as the Amundsen Sea Embayment. Together, these glaciers account for about ten percent of annual sea level rise. But according to Rignot and his coauthors, parts of East Antarctica are also an important component of the picture.
"This region is probably more sensitive to climate than has traditionally been assumed, and that's important to know, because it holds even more ice than West Antarctica and the Antarctic Peninsula together," said Rignot.
The researchers calculated that ice mass loss has accelerated because the rate of snowfall accumulation on inland basins has not kept up with a quickening melt rate at the perimeter. Glacier edges exposed to warm currents are melting fastest, and this will be an important factor as average global temperatures rise. “As climate warming and ozone depletion send more ocean heat toward those sectors, they will continue to contribute to sea level rise from Antarctica in decades to come,” Rignot said.
Sea ice is believed to play a key role in buffering Antarctica's glaciers from the effects of warm seawater. Antarctic summer sea ice coverage hit a record low in 2016, and it has remained below average levels since. The lowest recorded extent for January occurred this month.