Greenland's glaciers may be more susceptible to global warming than was thought.
Eric Rignot of the University of California, Irvine, and his colleagues used sonar to analyse the depths and profiles of three glaciers terminating in fjords in western Greenland. They found that the glaciers reach hundreds of metres farther down into the ocean than current maps suggest, allowing the ice to come into contact with a deep layer of warm Atlantic water. This leads to melting and the formation of deep cavities that probably boost the chances of large glacier chunks breaking off.
The authors note that these processes are not included in current ice-sheet models, and suggest that estimates of Greenland's contribution to sea-level rise will need to be increased.
Geophys. Res. Lett. http://doi.org/6dn (2015)