Summer season could be merciless to the planet’s remaining ice. Over the span of simply days in July 2023, seasonal heat led to the speedy disintegration of sea ice close to the junction of two massive outlet glaciers in northeast Greenland.
The 2 glaciers—Storstrømmen and L. Bistrup Bræ—are seen in this picture pair. Storstrømmen is the bigger of the 2, measuring about 20 kilometers (12 miles) huge and flowing southward. It joins with L. Bistrup Bræ and collectively their ice extends into fjord waters, forming the southernmost floating ice tongue in East Greenland.
The primary picture (left) exhibits the area on July 21, 2023. A pocket of persistent open water, or polynya, had fashioned inside the fjord’s sea ice close to the entrance of the glaciers. By July 25 (proper), the ocean ice had damaged out. Photos have been acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9 and the OLI on Landsat 8, respectively.
“The possible reason behind the speedy disintegration might be a wind-driven impact when the ocean ice was already heat and weak,” mentioned Christopher Shuman, a College of Maryland, Baltimore County, glaciologist based mostly at NASA’s Goddard House Flight Middle. “Consider it like a moist paper towel being pulled aside because the winds blew throughout the world.”
The primary picture exhibits the area on July 21, 2023. A pocket of persistent open water, or polynya, had fashioned inside the fjord’s sea ice close to the entrance of the glaciers.
By July 25 (proper), the ocean ice had damaged out. Photos have been acquired by the Operational Land Imager-2 (OLI-2) on Landsat 9 and the OLI on Landsat 8, respectively.
A few of the heat possible got here from Randsøen Lake on the fringe of the glacier junction, seen towards the left facet of the picture above. This persistent lake collects summer time meltwater from the margins of each glaciers. Streams atop the glaciers then carry the darkish, sediment-laden water into the fjord, the place the water continues to soak up extra warmth. The polynya grew bigger till the ocean ice broke out on July 23.
July 21, 2023
Apart from seasonally heat areas, the ocean water close to Storstrømmen and L. Bistrup Bræ is sort of chilly. In truth, analysis has proven that the shallow form of the seafloor prevents heat Atlantic water from accessing these glaciers and melting them from under—a typical phenomenon elsewhere round Greenland.
Nonetheless, retreat has been noticed on the glacier’s grounding zones—the area the place glacial ice resting on the bedrock begins to drift—for the reason that mid Nineteen Nineties. And the general current retreat of the glacier fronts is probably going associated to thinning of the glaciers by way of long-term processes similar to floor melting, and their adjustment to the speedy advance of Storstrømmen between 1978 and 1984.
NASA Earth Observatory photographs by Wanmei Liang, utilizing Landsat information from the U.S. Geological Survey. Story by Kathryn Hansen.
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