The Greenland tunnels that could speed ice melt♠

Guardian (UK): The Greenland ice sheet is riddled with channels that could quicken ice loss and speed sea level rise, a new study has revealed….Konrad Steffen, an ice expert at the University of Colorado, told a global warming conference in Copenhagen that the discovery could explain sudden and severe increases in ice movement seen during peak summer. Water channelled from the surface to the base of the ice sheet could speed up the way it slides across the bedrock. On a large scale, this could cause the ice sheet to break up much faster than expected.

Steffen worked with experts from Nasa to design a special camera that his team dangled inside the Greenland ice in summer 2007. They sent it down a "moulin" — a hole at the surface that carries away fast-flowing streams of surface water produced from melted ice. "I have lots of graduate students working on this project, but we couldn't find any volunteers who were willing to go down there to take a look," he joked.

Experts suspect such moulins carry melt water from the surface to the bedrock, but until now it had been impossible to track the flow to check where water went….

A glacier carving a valley in Greenland, NOAA