Thinning ice more fragile and mobile

The pronounced thinning of Arctic sea ice has made the ice pack more brittle and susceptible to wind drift.

The volume of Arctic sea ice decreased by one-third during 2007أ¢â‚¬â€œ11 compared with the 1979أ¢â‚¬â€œ2006 mean. In a model simulation, Jinlun Zhang at the University of Washington in Seattle and his colleagues demonstrate that the decline in volume substantially reduces the mechanical strength of the ice, thus boosting ice-drift speed and deformation rates.

Forecasts of ice-edge locations will become more challenging as the thinning and weakening of sea ice leads to a state of free drift, the authors note.