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Ice bridge ruptures in Antarctic Ice bridge ruptures in Antarctic
(about 4 hours later)
An ice bridge linking a shelf of ice the size of Jamaica to an island in Antarctica has snapped. An ice bridge linking a shelf of ice the size of Jamaica to two islands in Antarctica has snapped.
Scientists suggest the collapse could mean that the Wilkins Ice Shelf is on the brink of breaking away, and that it provides evidence of global warming. Scientists say the collapse could mean the Wilkins Ice Shelf is of the brink of breaking away, and provides further evidence or rapid change in the region.
The shelf has been retreating since the 1990s, but scientists say this is the first time it has lost one of the connections that keeps it in place. Sited on the western side of the Antarctic Peninsula, the Wilkins shelf has been retreating since the 1990s.
It broke off at the thinnest point of the 40-km (25-mile) strip of ice. Researchers regarded the ice bridge as an important barrier, holding the remnant shelf structure in place.
A European Space Agency satellite picture shows newly created icebergs floating in the sea on the western side of the Antarctic peninsula, which juts up from the continent towards South America's southern tip. Its removal will allow ice to move more freely between Charcot and Latady islands, into the open ocean.
"It's amazing how the ice has ruptured," David Vaughan, a glaciologist with the British Antarctic Survey, was quoted as saying by Reuters news agency. European Space Agency satellite pictures had indicated last week that cracks were starting to appear in the bridge. Newly created icebergs were seen to be floating in the sea on the western side of the peninsula, which juts up from the continent towards South America's southern tip.
"Two days ago it was intact. We've waited a long time to see this." Radar images last week showed the bridge on the point of breaking
Professor Vaughan stood on the ice bridge in January, putting in place a GPS tracker to monitor movement. Professor David Vaughan is a glaciologist with the British Antarctic Survey who planted a GPS tracker on the ice bridge in January to monitor its movement.
While the break-up will have no impact on sea level, it heightens concerns over the impact of climate change on this part of Antarctica. He said the breaking of the bridge had been expected for some weeks; and much of the ice shelf behind is likely to follow.
They say the Antarctic Peninsula has experienced unprecedented warming over the last 50 years. "We know that [the Wilkins Ice Shelf] has been completely or very stable since the 1930s and then it started to retreat in the late 1990s; but we suspect that it's been stable for a very much longer period than that," he told BBC News.
Several ice shelves have retreated in the past 30 years - six of them collapsing completely. "The fact that it's retreating and now has lost connection with one of its islands is really a strong indication that the warming on the Antarctic is having an effect on yet another ice shelf."
While the break-up will have no direct impact on sea level because the ice is floating, it heightens concerns over the impact of climate change on this part of Antarctica.
Over the past 50 years, the peninsula has been one of the fastest warming places on the planet.
Many of its ice shelves have retreated in that time and six of them have collapsed completely (Prince Gustav Channel, Larsen Inlet, Larsen A, Larsen B, Wordie, Muller and the Jones Ice Shelf).
Separate research shows that when ice shelves are removed, the glaciers and landed ice behind them start to move towards the ocean more rapidly. It is this ice which can raise sea levels, but by how much is a matter of ongoing scientific debate.
Such acceleration effects were not included by the UN's Intergovernmental Panel on Climate Change (IPCC) when it made its latest projections on likely future sea level rise. Its 2007 assessment said ice dynamics were poorly understood.