Researchers with NASA’s Operation IceBridge aerial polar ice survey have discovered the presence of large meltwater pools and raging rivers across the surface of a number of Greenland’s major glaciers, a “concerning” development due to the early melt of Arctic ice in the season. Typically, this level of ice melt doesn’t begin to occur until late May or early June, but the accelerated rate of warming in the Arctic is causing the ice to melt earlier in the year.
“While the blue water is breathtaking, the early onset of melt over Greenland is concerning for [the Earth],” tweeted NASA glaciologist Brooke Medley, part of the IceBridge team. Operation IceBridge is an ongoing aerial survey of the planet’s Arctic and Antarctic ice, as follow-ups to ICESat satellite ice thickness observations.
“Emerald green ponds weave around ice and debris near the terminus of Russell Glacier, which is showing signs of an early onset into the melt season,” according to NASA ICE’s twitter feed in May 7. In addition to Russell Glacier, the pooling was also spotted on Jakobshavn Isbræ in west-central Greenland, where temperatures last week went as high as the upper 50s to low 60s Fahrenheit, warmer than in “many places back home in [the U.S.],” according to a May 5 tweet from Medley.
Jakobshavn Isbræ is of particular interest to researchers, as the glacier extends deep into Greenland’s interior, and its outlet where the ice meets the sea is particularly sensitive to ocean temperature changes. The ice at the forefront of the glacier acts as a “cork” that helps prevent the rest of the river of ice behind it from rapidly flowing into the ocean, meaning any change in the ice face is concerning to researchers. This phenomenon occurred in 2002 when the Larsen B ice shelf in Antarctica collapsed, allowing the glacier behind it to flow rapidly into the ocean.
“When I say it’s like the cork on a champagne bottle, this really is a channel that potentially could tap the ice on the rest of the ice sheet,” warns NASA oceanographer Josh Willis, in a March interview with Mashable.
Liquid water that pools on the surface of glaciers is also much darker than the ice underneath it, so instead of reflecting the solar radiation back into space as ice does, the open water absorbs sunlight more readily, exacerbating the rate of melt even further.