Scientists are worried because a New York City-sized ice sheet has collapsed in East Antarctica, an area that has long been considered stable.
The collapse, captured by satellite images, marked the first time in human history that an ice sheet had collapsed in an icy region. It happened at the start of a strange warm spell last week when temperatures in some parts of East Antarctica were 70 degrees (40 degrees Celsius) warmer than normal. Satellite images show that the area has shrunk rapidly over the past few years, and now scientists say they are overestimating the stability of East Antarctica and its resistance to global warming, which is rapidly melting ice to the west and to the weaker peninsula.
Catherine Walker, an ice scientist at the Woods Hole Oceanographic Institute, said a 460-square-mile (1,200-square-kilometer) ice sheet collapsed in warm water between March 14 and 16 in the Conger and Glenzer glaciers. He said scientists have never seen it in this part of the continent and that makes it worrisome.
University of Minnesota ice scientist Peter Neff said, “The Glenger Conger ice shelf has probably been there for thousands of years and it will never be again.”
The problem is not the amount of ice this fall, Nef and Walker say. It’s insignificant. But more about where it happened.
Kneff says he is concerned that previous estimates about the stability of East Antarctica may not be as accurate. And this is important because if the frozen water in East Antarctica melts – and this is not a millennia-long process – it will raise the sea level by more than 160 feet (50 meters) across the globe. This is more than five times the risk of the West Antarctic ice sheet, where scientists have focused most of their research.
Scientists have seen ice sheets shrink slightly since the 1970s, Nef said. Then in 2020, the shelf ice erosion increases to about half lost every month, Walker said.
“We’re probably seeing the long-term effects of rising sea temperatures there,” Walker said. “It’s just melting and melting.”
And then last week’s warm-up “Probably something like that, you know, the last straw on the camel’s back.”
Read the Associated Press climate story at https://apnews.com/hub/climate
Follow Seth Borenstein on Twitter at borenbears.
The Associated Press receives support from a variety of individual foundations for climate and environmental coverage. See more about AP’s climate initiatives here. AP is solely responsible for all content.