A geologist amid 100,000 square kilometers (38,610 square miles) of lonely expanse and volcanic craters: Stefan Kröpelin crossed the Tibesti mountains in northern Chad to research the history of the Sahara’s climate ...
A geologist amid 100,000 square kilometers (38,610 square miles) of lonely expanse and volcanic craters: Stefan Kröpelin crossed the Tibesti mountains in northern Chad to research the history of the Sahara’s climate ...