In two days, the world’s fastest-moving glacier shed nearly 5 square miles worth of ice. Radar images from the Sentinel-1A satellite show the Jakobshavn glacier in western Greenland before and after the event, which took place between 14 and 16 August.
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The images suggest that before ice calving occurred, the glacier first moved westward from July 27 to August 13.
Comparing images taken by Sentinel-1A on 27 July, and 13 and 19 August, the new face of Jakobshavn glacier has been pushed inland by several km to what appears to be its furthest easterly location since monitoring began in the mid-1880s.
Assuming the ice is about 1400 m deep, this equates a volume of 17.5 cubic km – which could cover the whole of Manhattan Island by a layer of ice about 300 m thick.
“The calving events of Jakobshavn are becoming more spectacular with time, and I am in awe with the calving speed and retreat rate of this glacier”, said Eric Rignot, a glaciologist at the Jet Propulsion Laboratory, in a news release.
Events similar to the historic loss of ice have been documented on the glacier as well as it lost 2.7 square miles of ice once in 2010 and earlier in 2015.
The history of this calving event is also revealed in images taken by ESA’s Sentinel-2A satellite on 6 and 16 August. Some 35 billion tonnes of icebergs calve off and pass out of the fjord every year. Some observers speculated that the area of ice lost could very well be the largest on record.
Icebergs are often so large that they can not float away easily.
The glacier has been retreating further inland over the last 250 years and researchers have been studying it to understand how climate change is affecting sea levels.
Sentinel 1-A, is the 1st satellite of the Copernicus constellation, that has with state-of-the-art radar imaging technology.
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Since radar can “see” via clouds and at the hours of darkness, Sentinel-1A it’s notably helpful for maritime surveillance, ship security, sea-ice charting and ice-sheet monitoring. Glaciologists also note that the more the glacier loses additional pieces of ice, the more likely it is that new icebergs break off in the future.
