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Evidence for Megalake Chad, north-central Africa, during the late Quaternary from satellite data |
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| Authors: | Marc J. Leblanc Christian Leduc Frank Stagnitti Peter J. van Oevelen Chris Jones Linus A. Mofor Moumtaz Razack Guillaume Favreau |
| Affiliation: | aSchool of Geosciences, Monash University, Clayton 3800, Australia bIRD-UMR Hydrosciences, BP 64501, 34394 Montpellier cedex 5, France cSchool of Ecology and Environment, Deakin University, Warrnambool 3280, Australia dEuropean Space Agency, Keplerlaan 1, Postbus 299, 2200 AG Noordwijk, The Netherlands eSchool of Computer Science, Cardiff University, Newport Road, PO Box 916, Cardiff CF24 3XF, UK fSchool of Technology, University of Glamorgan, Pontypridd CF37 1DL, UK gUniversity of Poitiers, 40 avenue du Recteur Pineau, 86022 Poitiers Cedex, France |
| Abstract: | The existence of a very large Lake Chad during the late Quaternary, Megalake Chad, has long been questioned. A Megalake Chad would present strong evidence for climatic fluctuations of great magnitude during the Holocene in tropical Africa. In this paper we used satellite data from Landsat and Modis sensors to collect and analyse new information on landforms in a 2 000 000 km2 region of the Lake Chad Basin. We detected 2300 km of remains marking the ancient shoreline of Megalake Chad. The satellite data also indicated many Saharan rivers and relict deltas leading to the long paleoshoreline. Large dunefield flattenings were observed and interpreted as the result of wave-cut erosion by the paleolake. Similarities were noticed between the landforms observed along the paleoshoreline of Megalake Chad and that of the former Aral Sea. This finding has significant consequences for reconstructing paleohydrology and paleoenvironments through the Lake Chad basin, and continental climate change. |
| Keywords: | Lake Chad Paleohydrology Remote sensing Geomorphology Climate change Ancient shoreline |
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