IRVINE, Calif., Oct. 25 (UPI) -- Glaciers in West Antarctica are shrinking and retreating at record rates, threatening to further accelerate sea level rise.
According to researchers at NASA and the University of California, Irvine, melting on the underside of glaciers in West Antarctica is at an all-time high.
Researchers have been using satellite data to study the changes in glacial grounding lines, the boundary where a glacier loses contact with the Earth and begins to float in the ocean. A glacier's floating underbelly is called its ice shelf; the majority of glacial melting happens here.
As a glacier loses mass to melting, its ice shelf floats higher and higher, pushing its grounding line backward. The phenomenon is called glacial retreat. Satellite data -- detailed in a study published in August -- suggests the phenomenon is happening at an accelerated rate.
"We continue to measure the evolution of the grounding line of these glaciers, which helps us determine their stability and how much mass the glacier is gaining or losing," Bernd Scheuchl, an earth system scientist at UCI, explained in a news release. "Our results show that the observed glaciers continue to lose mass and thus contribute to global sea level rise."
A new study, published today in the journal Nature Communications, suggests record ice loss is to blame for receding glacial grounding lines.
Using laser altimeters, researchers have been tracking changes in the thickness and height of glaciers in West Antarctica.
Ala Khazendar, a researcher at NASA's Jet Propulsion Laboratory, said he might not have believed the measurements had multiple instruments not all arrived at the same numbers.
"I wouldn't have believed what I was looking at, because the thinning was so large," he said.
The latest data suggests an influx of warm ocean water is to blame for the rapid ice loss that encouraged glacial retreat. The question now is how the glaciers and their grounding lines will behave moving forward.
The grounding line of one of the studied glaciers has advanced since 2011, following a long period of retreat. Will other glaciers follow the same pattern, or keep retreating? Only time and fresh satellite surveys will tell.