Saturday, September 8, 2007

Uh oh: Melting ice cap triggering earthquakes, SLR estimates outdated

Guardian (UK): The Greenland ice cap is melting so quickly that it is triggering earthquakes as pieces of ice several cubic kilometres in size break off. Scientists monitoring events this summer say the acceleration could be catastrophic in terms of sea-level rise and make predictions this February by the Intergovernmental Panel on Climate Change far too low.

The glacier at Ilulissat, which supposedly spawned the iceberg that sank the Titantic, is now flowing three times faster into the sea than it was 10 years ago.

Robert Corell, chairman of the Arctic Climate Impact Assessment, said in Ilulissat yesterday: "We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at 2 metres an hour on a front 5km [3 miles] long and 1,500 metres deep. That means that this one glacier puts enough fresh water into the sea in one year to provide drinking water for a city the size of London for a year."

…Dr Corell, director of the global change programme at the Heinz Centre in Washington, said the estimates of sea level rise in the IPCC report were based on data two years old. The predicted rise this century was 20-60cm (about 8-24ins) , but it would be at the upper end of this range at a minimum, he said, and some believed it could be two metres. This would be catastrophic for European coastlines.

…Veli Kallio, a Finnish scientist, said the quakes were triggered because ice had broken away after being fused to the rock for hundreds of years. The quakes were not vast - on a magnitude of 1 to 3 - but had never happened before in north-west Greenland and showed potential for the entire ice sheet to collapse.

Dr Corell said: "These earthquakes are not dangerous in themselves but the fact that they are happening shows that events are happening far faster than we ever anticipated."

No comments: