12 July 2002
Vol 297, Issue 5579

About The Cover

Cover image expansion

COVER Meltwater stream flowing into a moulin in the ablation zone of the Greenland ice sheet. Accelerations of ice flow in summer are closely related to variations in air temperature and surface melting, and indicate that meltwater quickly travels through 1000 m of ice and enhances basal sliding. These observations reveal a mechanism for dynamic response of ice sheets to climate change. 218 [Photo: R. J. Braithwaite]