Aerial photos and satellite data helped scientists estimate ice mass losses in Antarctica between 1979 and 2017. Photo by Joe MacGregor/NASA
Jan. 14 (UPI) -- Antarctica is melting and shedding ice at an accelerated clip. According to a new study, Antarctica is losing six times more ice mass than it was 40 years ago.
Using a combination of high resolution aerial photographs, satellite images and satellite radar interferometry, scientists estimated Antarctica's annual ice sheet balance between 1979 and 2017. To estimate how much ice was gained and lost each year, researchers compared snowfall accumulation in Antarctica's interior with ice discharge along the groundling lines of the continent's glaciers.
Between 1979 and 1990, Antarctica lost 40 gigatons -- or 40 billion tons -- of ice mass annually. Between 2001 and 2017, the number jumped to 252 gigatons. Melting rates also dramatically accelerated over the four decades.
East Antarctica's glaciers are melting and shedding ice mass at a surprisingly fast rate.
"The Wilkes Land sector of East Antarctica has, overall, always been an important participant in the mass loss, even as far back as the 1980s, as our research has shown," Eric Rignot, glaciologist and professor of earth sciences at the University of California, Irvine, said in a news release. "This region is probably more sensitive to climate [change] 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."
According to the new research, published this week in the journal PNAS, all that ice loss resulted in more than half an inch of sea level rise during the 40-year timespan.
"That's just the tip of the iceberg, so to speak," said Rignot, who is also a senior scientist at NASA's Jet Propulsion Laboratory. "As the Antarctic ice sheet continues to melt away, we expect multi-meter sea level rise from Antarctica in the coming centuries."
The regions of Antarctica losing the most ice mass are adjacent to warm ocean water.
"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.
The latest findings confirm the conclusions of several recent studies, including a survey of melting in East Antarctica. Earlier studies also identified warm ocean water as a primary driver of Antarctic ice loss.