Arctic glacier to lose Manhattan-sized 'tongue'
14 July 2009 by Catherine Brahic
The biggest glacier in the Arctic is on the verge of losing a chunk of ice the size of Manhattan. A group of scientists and climate change activists who are closely monitoring the Petermann glacier's ice tongue believe the rapid flow of ice is in part due to warm ocean currents moving up along the coast of Greenland, fuelled by global warming.
During the summer of last year, Jason Box of Ohio State University in Columbus noticed a huge crack in the glacier's floating ice tongue, which acts as a conveyor belt, pushing the glacier's ice through a fjord and out to sea. The crack extended almost completely from one side of the fjord to the other, 16 kilometres away.
This prompted Box and colleagues to return this year on the Arctic Sunrise, a Greenpeace vessel. The researchers are equipped with an arsenal of cameras and sensors, which they have been setting up on surrounding cliffs as well as on the ice itself.
Break imminent
Stitched together, the pictures they are taking will provide a blow-by-blow animation of the event. "We're looking on a minute by minute basis at what it's doing, how it's moving in relation to the rest of the glacier, and looking for that critical point where it fractures and breaks off," says Alun Hubbard, a glaciologist at the University Of Wales, UK.
The team believes this will happen within weeks. Only yesterday, a 3-square-kilometre chunk broke away. There are now more than 10 cracks in the ice, some 500 metres wide. The researchers expect the ice tongue to break up within the coming weeks.
When this happens, an island of ice the size of Manhattan, spanning 100 km2 holding 5 billion tonnes of ice, will break free and drift out to sea.
Arctic glacier to lose Manhattan-sized 'tongue' - environment - 14 July 2009 - New Scientist
14 July 2009 by Catherine Brahic
The biggest glacier in the Arctic is on the verge of losing a chunk of ice the size of Manhattan. A group of scientists and climate change activists who are closely monitoring the Petermann glacier's ice tongue believe the rapid flow of ice is in part due to warm ocean currents moving up along the coast of Greenland, fuelled by global warming.
During the summer of last year, Jason Box of Ohio State University in Columbus noticed a huge crack in the glacier's floating ice tongue, which acts as a conveyor belt, pushing the glacier's ice through a fjord and out to sea. The crack extended almost completely from one side of the fjord to the other, 16 kilometres away.
This prompted Box and colleagues to return this year on the Arctic Sunrise, a Greenpeace vessel. The researchers are equipped with an arsenal of cameras and sensors, which they have been setting up on surrounding cliffs as well as on the ice itself.
Break imminent
Stitched together, the pictures they are taking will provide a blow-by-blow animation of the event. "We're looking on a minute by minute basis at what it's doing, how it's moving in relation to the rest of the glacier, and looking for that critical point where it fractures and breaks off," says Alun Hubbard, a glaciologist at the University Of Wales, UK.
The team believes this will happen within weeks. Only yesterday, a 3-square-kilometre chunk broke away. There are now more than 10 cracks in the ice, some 500 metres wide. The researchers expect the ice tongue to break up within the coming weeks.
When this happens, an island of ice the size of Manhattan, spanning 100 km2 holding 5 billion tonnes of ice, will break free and drift out to sea.
Arctic glacier to lose Manhattan-sized 'tongue' - environment - 14 July 2009 - New Scientist
