Analysis of a decade-long record of Greenland's glaciers suggests that the ice sheets are not accelerating towards the ocean as much as previously forecast.

Earlier work on a small number of glaciers had uncovered large increases in speed. Using satellite radar data to calculate the movements of more than 200 of the island's ocean-terminating glaciers between 2000 and 2010, Twila Moon at the University of Washington, Seattle, and her colleagues found a range of accelerations and decelerations, with an overall acceleration. Glaciers in the northwest and southeast — where approximately 80% of ice loss occurs — accelerated by about 30% over the ten-year period, whereas glaciers elsewhere exhibited a generally steady flow.

Glacial melting can lead to an increase in sea level. However, Moon and colleagues' data suggest that Greenland's current glacial acceleration is unlikely to produce the previously forecast worst-case scenario of a 0.5-metre sea-level rise by 2100.


Science 336, 576–578 (2012)