Landsat Images Show Greenland Glaciers Changing Over 46 Years

first_imgStay on target Glaciers Have Lost More Than 9 Trillion Tons of Ice Since 1961Melting Glaciers Expose Dead Bodies on Mount Everest NASA shared Landsat images of Greenland’s glaciers and they show how these icy structures have significantly changed over the last half century.The chilling images, which focus on the group of glaciers that empty into Greenland’s Sermilik Fjord, detail appearance and composition changes in hi-res form, NASA said in a press release. Landsat images taken in August 2019 were compared to Landsat images snapped in 1972, and they show that these massive ice hubs are changing in color and melting at shocking rates.Three of Greenland’s glaciers are seen in this Landsat 8 image from 2019 and a composite image from Landsat 1 scenes collected in 1972. (Photo Credit: NASA / Christopher Shuman)In a true-color Landsat 8 satellite image from August 12, 2019, the glaciers appear to have a brownish-grey hue. NASA says the color shows that the surface of these glaciers have melted and it’s a process that concentrates dust and rock particles and results in a darker, recrystallized ice sheet surface.What’s alarming about this image is that the darker melt surface in 2019 extends much farther on the ice sheet than it did in 1972, when the first Landsat satellite collected data on the area, according to Christopher Shuman, a glaciologist with the University of Maryland, at NASA Goddard Space Flight Center in Greenbelt, Maryland.Greenland’s Helheim Glacier is shown in close-up images from 2019 and 1972. (Photo Credit: NASA / Chris Shuman)By comparing the 2019 image to the 1972 image, scientists can also observe how Helheim Glacier and Midgard Glacier have retreated over the past 46 years. As one of the largest and fastest flowing glaciers in Greenland, Helheim Glacier has retreated roughly 4.7 miles up a wide fjord (deep inlet of the sea between high cliffs), leaving a mess of sea ice where its calving front used to be located. East of Helheim Glacier, Midgard Glacier has retreated approximately 10 miles and splits into two branches further up the fjord.“There’s a lot more bare rock visible now, which used to be covered with ice. And all these little glaciers are all getting slammed, as well as the bigger ones like Helheim, Fenris, and Midgard,” Shuman said. “There are scores of examples of change just in this one area.”NASA’s Oceans Melting Greenland campaign flew over an area of open water at the Helheim Glacier’s calving front on August 15, 2019. (Photo Credit: NASA / Josh Willis)Another Landsat close-up image of the Helheim Glacier, which was taken on August 15, 2019, shows a patch of open water at the calving front. Three days after the Landsat 8 satellite snapped the image over Helheim Glacier and its neighboring ice structures, NASA’s Oceans Melting Greenland (OMG) project flew over the open patch of water in an airplane and dropped a temperature-measuring probe, which detected warm water at the ice front. The project is analyzing how oceans melt glaciers from below, even as air temperatures heat up the ice from above.Unusually warm air temperatures during the summer months have caused a record melt across Greenland. Roughly 90 percent of the surface of Greenland’s ice sheet has melted between July 30 and August 2, during which time approximately 55 billion tons of ice melted into the ocean, according to the National Snow and Ice Data Center.More on Have Lost More Than 9 Trillion Tons of Ice Since 1961Melting Glaciers Expose Dead Bodies on Mount EverestIncredible Images From Space Capture the Death of a Glacierlast_img

Leave a Reply

Your email address will not be published. Required fields are marked *