An established rift in the Larsen C Ice Shelf, formerly constrained by a suture zone containing marine ice, grew rapidly during 2014 and is likely in the near future to generate the largest calving event since the 1980s and result in a new minimum area for the ice shelf.
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Moreover, researchers studying the widening crack in a 2015 paper predict that after the loss of this ice, the remaining shelf could be unstable and lose more mass.
Scientists focused on Antarctica have been keenly observing the rapid progression of a large crack on the ice.
The Midas team found that not only is the massive crack in the ice shelf widening, but it is spreading across the ice shelf at an increasing rate, threatening to carve out an iceberg the size of DE and in turn create further instability in a large section of the ice, about the size of Scotland. “It’s a lot like predicting an quake – exact timings are hard to come by”.
Last year, the team discovered that there is warm water circulating underneath a floating portion of the glacier and that it is causing more melting than would have been expected.
Satellite image of the Larsen B ice shelf after it collapsed, on 31 January, 2002.
So in sum, we’re talking about a possible ice island in the Southern Ocean that is as large as one of the smallest USA states. “Once the iceberg has calved off completely, there might be a tendency for the ice front to crumble backwards”. So when would the ice break off? As the summer air warmed, sometimes reaching above 0 C, it caused lakes to form atop the glacier (the warmer temperatures were seen often in the summer of 2012).
Nasa had published a study in May previous year explaining how Antarctica’s Larsen B ice shelf is suffering the same fate and is likely to shatter into hundreds of icebergs before the end of the decade. Researchers estimate that freeing that outflow would raise global sea levels by just under 4 inches, according to the Post. “The evidence coming together is painting a picture of East Antarctica being much more vulnerable to a warming environment than we thought”, Siegert says.
Larsen C has a rift in it that’s grown steadily over the past five years. However, the loss of ice can accelerate the seaword flow of non-floating glacial ice, which can lead to a rise in the sea level. It will also be the third biggest collapse ever recorded, as well as the largest from the Larsen C ice shelf. As Mooney points out, a large loss of ice from Larsen C won’t necessarily be a awful thing for the world’s oceans – not immediately, at least.
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The MIDAS team isn’t as optimistic, so unfortunately, we’re left to wait and see when this massive chunk will break off, and what the consequences will be for life on Earth. The continent is nearly completely covered by ice sheets over a kilometre deep, with the coastlines supporting floating ice shelves like the Larsen C. The largest of three ice shelves located along the east coast of the Antarctic Peninsula, Larsen C’s impending break-up has been predated by the deterioration of Larsen A in 1995 and the loss of Larsen B which broke off in 2002. If the crack continues on its current pace, we may soon learn who is correct.
