24 August 2007
Vol 317, Issue 5841

About The Cover

Cover image expansion

COVER The rapidly retreating margin of Columbia Glacier, as seen from the air above iceberg-riddled Columbia Bay, Prince William Sound, Alaska. Exposed bedrock on the valley margins shows that the glacier has thinned by more than 400 meters since the early 1980s. See page 1064. Photo: R. S. Anderson