09 May 2008
Vol 320, Issue 5877

About The Cover

Cover image expansion

COVER Lake Boku at the Ounianga oasis in remote northeastern Chad, one of the few remaining bodies of water in the almost rainless Sahara. Still sustained by fossil groundwater dating from the humid past, it is doomed because of encroaching dunes. See page 765.

Photo: S. Kröpelin