Mount Balfour and Fleming Glacier near the Antarctic Peninsula.
Photo: © Joe McGregor for NASA

Ice loss in Antarctica is increasing dramatically

The melting speed of the Antarctic Ice Sheet increased dramatically over the last four decades. East Antarctica is manifestly less stable than presumed, even though the main mass loss is experienced in West Antarctica

Antarctic Ice is melting far more quickly than presumed warned researchers from the University of California, Irvine, NASA’s Jet Propulsion Laboratory and the Netherlands’ Utrecht University in January 2019. 

According to them, Antarctica experienced a sixfold increase in yearly ice mass loss between 1979 and 2017. They found that the accelerated melting caused global sea levels to rise more than half an inch during that time.

The researchers conducted a very long assessment of remaining Antarctic ice mass. Spanning four decades, the project was also geographically comprehensive; the research team examined 18 regions encompassing 176 basins, as well as surrounding islands.

One of the key findings of the project is the contribution East Antarctica has made to the total ice-mass-loss picture in recent decades. This region is probably more sensitive to climate change than traditionally assumed. Nevertheless, the mass loss from West Antarctica is three to four times larger than that from East Antarctica and the Peninsula, respectively.

During the entire period, the mass loss concentrated in areas closest to warm, salty, subsurface, circumpolar deep water (CDW), consistent with enhanced polar westerlies pushing CDW toward Antarctica to melt its floating ice shelves, destabilize the glaciers and raise sea level.

The pace of melting rose dramatically over the four-decade period. From 1979 to 1990 it averaged 40 gigatons annually and increased to an average loss of 50 gigatons per year between 1989 and 2000. In the following decade (1999 to 2009) the average loss rate rose to 166 gigatons annually and then jumped to 252 gigatons per year for the period 2009 to 2017.

(UCI/ile)

More information: Four decades of Antarctic Ice Sheet mass balance from 1979–2017 https://www.pnas.org/content/early/2019/01/08/1812883116