There is a hypothesis that the Great Antarctic [Ice] Shield is gradually sliding into the sea at a rate of about 330 feet a year.… To learn how much ice is accumulated and how much of it slides off the continent, scientists set up special survey stakes…. During their latest trek they checked these survey stakes and determined the speed with which the ice masses creep.
Satellite monitoring that began in the early 1990s has let scientists precisely measure how fast ice moves across Antarctica. Ice near the heart of the continent today creeps coastward at less than 10 meters per year, while ice close to the coast picks up the pace, traveling up to a few kilometers per year. Due to global warming, Antarctica is losing ice faster than it can be replaced. From 2012 to 2017, the continent shed an average of about 219 billion metric tons of ice annually, compared with 76 billion tons per year during the previous two decades. Overall, Antarctic ice melt from 1992 to 2017 boosted global sea level by 7.6 millimeters on average (SN: 7/7/18, p. 6).