Lakes in the Sahara
A journey to north-east Chad
The large lakes in the Sahara still hold many secrets. With the help of the lake sediments, geologists are gaining new insights into the variable history of climate and environment in arid Africa.
While previous investigations of lake deposits in the Egyptian and north-Sudanese deserts allowed the climate history of the last humid period in the Sahara to be reconstructed for the time between approximately 10,000 and 1,500BCE, practically no data existed for the following period. However, indicators of environmental and climate change in the world’s largest desert during the past 3,500 years are extremely valuable for inferring recent dynamics in arid regions or for climate modelling in ‘Global Change’ programmes. The remote north-eastern part of Chad remains to this day the least explored region of the Sahara, if not the whole of Africa because of its extremely harsh desert environment and notorious insecurity. The Ounianga lakes have therefore been neglected as a field for geoscientific research since their discovery by the French military geographer Jean Tilho early in the 20th century. It was not until January 1999 that a five week expedition was started in cooperation with Uwe George from GEO magazine in the hope of revealing the secret of the largest lakes in theSahara. The aim was to investigate the palaeoclimatic potential of the Ounianga lakes and the surrounding areas.
Africa Research Unit, Institute of Prehistoric Archaeology,
University of Cologne,
50823 Cologne, Germany
Dr. Stefan Kröpelin was the leader of the geo-archaeological subprojects “Sudan” and “Chad” in Collaborative Research Centre 389 “Arid Climate, Adaptation and Cultural Innovation in Africa” (ACACIA; ”Kultur- und Landschaftswandel im ariden Afrika – Entwicklungsprozesse unter ökologischen Grenzbedingungen”).