In two days, the world’s fastest-moving glacier shed almost 5 square miles worth of ice. That’s enough to cover Manhattan in about 1,000 feet of ice, the European Space Agency estimated, assuming the ice is 4,600 feet thick.
The ice broke off Jakobshavn, a glacier in western Greenland that’s known for losing big chunks of ice during the summer. Here’s what the glacier looked like on July 31, two weeks before the ice’s big move on August 14.
And here it is photographed by satellite on August 16, when the ice stopped moving.
The lost ice is the result of a process called “calving.” That’s what happens when ice breaks off the lowest part of a glacier, in this case the eastern side. The European Space Agency says this might be the most far inland the glacier’s been pushed since the 1800s — and researchers think the glacier will keep heading that way because it’s unstable.
“What is important is that the ice front, or calving front, keeps retreating inland at galloping speeds,” Eric Rignot, a glaciologist at the Jet Propulsion Laboratory said in a news release. The glacier’s been speeding up over the past few years — during summer 2012, Jakobshavn moved at a rate of 10 miles per year, according to NASA’s Earth Observatory.
Here’s the outline of the ice that fell off the glacier:
Once the ice gets separated from the main glacier, it turns into icebergs that travel down fjords — long, narrow inlets of water that feed into the ocean, which is the Atlantic in this case.
The calving off the Jakobshavn glacier isn’t nearly as big as the ones happening in Antarctica. Even so, the speedy glacier poses a big threat: “This glacier alone could contribute more to sea level rise than any other single feature in the Northern Hemisphere,” NASA’s Earth Observatory notes.
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