They are losing four times as much ice as less than twenty years ago, according to a study
Thousands of small glaciers not connected to the main Greenland ice sheet they are losing four times the ice they had in 2003, thus contributing significantly to sea level rise.
published in the magazine Geophysical Research Letters AGU, a new study focused on “fringe” glaciers, which are glaciers with areas less than 0.05 km2 and do not receive ice flow or accumulation from the Greenland Ice Sheet.
There are about 20,300 outlying glaciers in Greenland, and although they represent only about four percent of Greenland’s ice-covered areas, they contribute up to 11 percent of the total ice loss from Greenland’s ice-covered areas. This colossal melting rate makes a major contribution to sea level rise.
Specifically, the melting of peripheral glaciers has increased by more than 50% in the last two decades, as recorded by altimetry data from ICESat and ICESat-2, the study found. On average, 42.3 gigatons of ice melted each year from October 2018 to December 2021.. By comparison, 27.2 gigatonnes melted annually from February 2003 to October 2009.
They lose four times more mass annually
Outlying glaciers are now losing four times more ice mass annually than in 2003, the new study concludes.
“Ice loss from these small glaciers this is because they are more sensitive to ongoing temperature changes and therefore melt faster than what we see in many other places in the Arctic,” Shfaqat Abbas Khan, lead author of the study and professor at the National Space Institute of the Technical University of Denmark, said in a statement. “We can see that there is a marked increase in melting of glaciers in northern Greenland. This shows that the ice masses in Greenland are very unstable and that contribute significantly to global sea level rise.
“I think it’s really valuable to shed light on whether these glaciers exist and how they’re changing,” said Twila Moon, a glaciologist at the University of Colorado Boulder who was not involved in the study. “Many people want to know how much sea level will change in a specific place, and when that will happen. To answer those questions, we need a very detailed understanding of where we’re losing ice at different times,” including the largest ice sheets and largest glaciers. little ones.
melted water going into the sea
Global warming is causing significant melting overall in Greenland’s ice sheet and glaciers, but location and rate of melting are uneven. That makes quantifying ice loss from even small glaciers critical to understanding how much freshwater is flowing off the island.
“Many studies have documented the state of the Greenland ice sheet over the past decade. But even though ice loss from peripheral glaciers is such a large part of Greenland’s total ice loss, there are very few studies that document the health of these peripheral glaciers,” said study co-author William Colgan, a glaciologist at the National Geological Survey of Denmark and Greenland.
Low rates of ice loss, such as those found in the high mountains of eastern Greenland that receive heavy snowfall, are offset by intense melting from peripheral glaciers in northern Greenland. Although isolated glaciers are not part of the Greenland Ice Sheet, which is the focus of most Greenland-driven sea-level rise research, it is important to include them in the total Arctic melt budget to accurately calculate how much the region contributes to sea level rise.
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