“Ice isn't a good building material-you could never build a skyscraper out of it because it collapses under its own weight if it's more than 90 meters tall.” And at the very edge of the Helheim Glacier, the wall of ice is about 70 meters (about 230 feet) tall. “Calving happens,” says Kristin Poinar, a glaciologist from the University of Buffalo. This event in itself isn’t necessarily a harbinger of climate doom. From events like these, they can “learn how big things break,” he says, which will tell them how the ice will behave in the future-when the climate is even warmer. And they use that information to figure out how much more ice might be lost in the future.ĭavid Holland, an NYU oceanographer who was perched in a prime viewing spot when the glacier calved, explains that the physics that control both big calving events like this one, or even bigger ones (in 2010, another glacier in Greenland lost a piece about 100 square miles in area), are very similar. Most ice in both Greenland and Antarctica spills out into the ocean from just a few spots-so understanding the physics at work at these spots, like the towering ice wall at the bottom of Helheim Glacier, helps scientists understand how and why, exactly, the glaciers lose their ice. Antarctica currently dumps about 100 billion tons each year, but that number is very likely to increase fast in coming decades. Greenland spits about 270 billion tons of ice into the ocean each year-more when it's warmer and a little less during cool years. Ice sheets, like those in Greenland and Antarctica, lock up about two percent of all the water that exists on the world’s surface (most of the rest, unsurprisingly, is in the ocean). And the ice sheets shed faster and faster each year. But when you add up this plus all the other pieces that slough off from both Greenland and West Antarctica each year, the effect adds up: about a millimeter a year, or a few inches over the past 25 years. This particular chunk of glacier-about 10 billion tons of ice, enough to give every American more than 600 10-pound bags of ice-won't have a noticeable effect on the waves that lap at the beaches in Sydney, Cape Cod, or Honolulu. ( See what the world would look like if all the ice melted.) When ice that was previously sitting on land, like this piece of the glacier, falls into the ocean and melts, the ocean gets a little fuller. A chunk of ice the size of lower Manhattan-four miles wide, a mile across, and half a mile thick-broke off of the Helheim Glacier in Greenland and tumbled into the sea a few weeks ago.
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