“The Larsen C ice shelf will not collapse for another few decades, most likely, but this calving is unique in the history of the ice shelf since first seen by human eyes by the Norwegian explorer Carl Anton Larsen in 1893.” “For me, there is no doubt that this event is not part of a natural cycle,” he said by email. The case for a climate-related cause is not nearly as good as for other areas of Antarctica.”īut Eric Rignot, the NASA and University of California-Irvine researcher, is convinced of a climate role. “It’s unclear if this is a new trend for this area of Antarctica. “I think we’re all scratching our heads as to just what combination of changes in the ice, air, and ocean caused this,” said Scambos. But at the same time, Larsen C is the next ice shelf in line in a southward progression that has previously seen the collapse of the Larsen A and Larsen B ice shelves, making this occurrence at least suspicious. ![]() Scientists don’t have all the data that they would need to show what is happening in the environment of the floating Larsen C ice shelf, which is affected not only but air temperatures above it but also ocean temperatures below it.Īntarctica’s ice shelves do carve large pieces regularly, a natural process. There is a debate over whether this event can be attributed in any way to climate change. The break began several years ago but had quickened its advance in the last year, increasingly convincing scientists that the iceberg detachment was inevitable, despite the fact that it is actually winter in Antarctica right now. Then the iceberg, or its pieces, will become swept up in the Antarctic Circumpolar Current, which encircles the entire continent, flowing in a west-to-east direction.īefore the break, a rift across the Larsen C ice shelf had extended more than 100 miles in length, and just a few miles of remaining ice connected the nascent iceberg to the shelf. First, it will be swept up in the Weddell Sea Gyre, an elongated circuit of ocean flow, and then should pass to the west of South Georgia and the South Sandwich Islands, according to Helen Amanda Fricker, an Antarctic expert at the Scripps Institution of Oceanography. The iceberg’s progress is expected to be northward in the direction of South America. Scientists will track the iceberg using satellite imagery and should be able to get a chance at regular glimpses even in Antarctic night, due to the use of radar and thermal imaging. That is a little bit smaller than the state of New Jersey. If you add together all the ice lost from the various Larsen ice shelves since the 1970s, it is around 7,350 square miles, according to figures provided by Rignot. “A similar evolution was seen on Larsen A and B before they collapsed in 19 respectively,” he added, referring to Larsen C’s now missing northern cousins. “The ice front is now almost 40 km farther back,” said Rignot by email. Indeed, the front of Larsen C ice shelf has retracted back farther than ever previously observed, according to Eric Rignot, a glaciologist with NASA and the University of California-Irvine. Calving refers to the process in which chunks of ice break away from an ice shelf or glacier into the ocean. “This calving is a little bit different, because it makes the ice shelf so much smaller,” Scambos said. It came after the shelf had grown considerably and extended much farther out into the Weddell Sea than it does now. ![]() Larsen C also lost an even larger piece in 1986, Scambos said, but that occurred in considerably different circumstances. It was the biggest iceberg ever recorded. That was almost twice the size of this one and broke off the Ross Ice Shelf, Antarctica’s largest floating ice body. ![]() Indeed, it means that the Larsen C ice shelf, previously the fourth-largest of its kind in Antarctica, is now probably only the fifth- or sixth-largest, Scambos said.Įven larger icebergs than this have broken off of Antarctica in the past, however, including a berg of over 4,000 square miles, dubbed B15, in 2000. The change is large enough that it will trigger a redrawing of the Antarctic coastline, according to Ted Scambos, senior research scientist with the National Snow and Ice Data Center. “Icebergs from this region occasionally make it out beyond the tip of the Antarctic Peninsula, but it will take a while for that to happen to this iceberg or its fragments, and there is not a lot of shipping in the area that I am aware of,” he explained.
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