An ice island measuring 260 square kilometres broke off from one of Greenland’s two main glaciers, scientists say, the biggest such event in the Arctic in nearly 50 years.
The new ice island, which broke off on Thursday, will enter a remote place called the Nares Strait, about 1,000 kilometres south of the North Pole between Greenland and Canada.
Professor of ocean science and engineering at the University of Delaware, Andreas Muenchow, said he had expected an ice chunk to break off from the Petermann Glacier, one of the two largest remaining ones in Greenland, because it had been growing in size for seven or eight years. But he did not expect it to be so large.
“The freshwater stored in this ice island could keep the Delaware or Hudson Rivers flowing for more than two years,” Professor Muenchow said.
“It could also keep all US public tap water flowing for 120 days.”
He said it was hard to judge whether the event occurred due to global warming because records on the sea water around the glacier have only been kept since 2003.
The flow of sea water below the glaciers is one of the main causes of ice calvings off Greenland.
“Nobody can claim this was caused by global warming. On the other hand nobody can claim that it wasn’t,” Professor Muenchow said.
The initial discovery of the calving was made by Trudy Wohlleben of the Canadian Ice Service.
The ice island could fuse to land, break up into smaller pieces, or slowly move south where it could block shipping, Professor Muenchow said.
The last time such a large ice island formed was in 1962 when the Ward Hunt Ice Shelf calved an island.
Smaller pieces of that chunk became lodged between real islands inside Nares Strait.