Lake Chad

Major saline systems at the borders of the Sahara include the large, ephemeral playas of Tunisia and Algeria, and the large, areally fluctuating, Lake Chad. Bryant et al. (1994) have described the principal control of the geochemistry of the Chott el Jerid in Tunisia by runoff from Cretaceous through Quaternary... 

Velde B., Pedro G., and Carmouze J.-P. (1978) PeUetal nontronite formation in recent sediments of Lake Chad. Chem. Geol. 23, 139-149. 

Figure 9.8 (A) Clayey and calcareous diatomite from northern Lake Chad. Various sedimentary layers can be seen they correspond to transition from a lacustrine environment (bottom) to a palustrine environment (top), from sub-arid to arid conditions. (Photograph courtesy of Professor A. Durand.) (B) Spherule-like crystals of kenyaite (hydrous sodium silicate) precipitated in apolyhaline interdunal ponds, Lake Chad.

Sebag, D., Verrecchia, E.P. Durand, A. (1999) Biogeochemical cycle of silica in an apolyhaline interdunal Holocene lake (Chad, N Guigmi region, Niger). Naturwissenschaften 86, 475 478. 

Sebag, D., Verrecchia, E.P., Lee S.J. Durand A. (2001) The natural hydrous sodium silicates from the northern bank of Lake Chad occurrence, petrology and genesis. Sedimentary Geology 139, 15-31. 

Eugster, H.P. Maglione, G. (1979) Brines and evaporites of the Lake Chad basin, Africa. Geochimica et Cosmochimica Acta 43, 973-981. 

Ghienne, J.-F., Schuster, M., Bernard, A., Duringer, P. Brunet, M. (2002) The Holocene giant Lake Chad revealed by digital elevation models. Quaternary International 87, 81-85. 

The guinea worm infection is a very old parasitic disease caused by Dracuncu-lus medinensis which are enlongated thread-like filarial worms living in the deep connective and subcutaneous tissues of man. The infection has been reported from different parts of Africa, South America and Asia however, it is endemic in Cameroon, Lake Chad, Sudan, Uganda and India. 

Fig. 19.17 Taylor Valley is not entirely ice-free because the Taylor Glacier descends from the polar plateau and terminates at Lake Bonney (Fig. 3.7). Taylor Valley also contains several additional meltwater lakes including Mummy Pond between the Matterhorn and Suess glaciers, lakes Chad and Hoare between the Suess and Canada glaciers, and Lake Fryxell between the Canada and Commonwealth glaciers (not shown), all of which...

Fig. 19.46 The glacial meltwater in Taylor Valley flows into three closed drainage basins even though the valley itself opens onto McMurdo Sound. The principal lakes in these basins are Lake Bonney (Fig. 3.7), Lake Chad and Lake Hoare, and Lake Fryxell. Lake Bonney receives brine discharged by the Taylor Glacier at Bloodfalls (also known as Taylor Red Cone). Lakes Chad and Hoare collect meltwater...

Lake Bonney Mummy Pond Lake PopplewelP Lake Chad Lake Hoare Lake Fryxell Lake House Lake Joyce Koettlitz Glacier Lake Miers Lake Pewe Lake Colleen Hidden Lake Lake Keyhole Ward Lake Alpha Lake ... 

The hydrology of Nigeria is dominated by two great river systems, the Niger and Benue, and also the third, the Chad systems. With the exception of a few rivers that empty directly into the Atlantic Ocean, most others flow ultimately into either of the two major systems only a few flow into the Lake Chad in the northeastern part of the country. The Niger and Benue rivers are separated by a primary watershed extending northeast and northwest from the Jos Plateau, which is the main source of their principal tributaries. Northwest of the Plateau lies the elevated, drift covered plains of central Hausa-land, which is drained by numerous streams, all flowing outwards to join the major tributaries. 

Ocean water Arctic sea ice Marine moisture (sub)tropical precipitation Dead sea/lake chad Temperate zone precipitation Alpine glaciers Greenland glaciers Antarctic ice... 

Fig. 13. Examples of non-troublesome noise. Lake Chad, central and western region. - Nimbus 3, infrared albedo (in %, band 0.7-1.3 fim), orbit 3045, 27 November 1969. - Key (starting with darkest shade) reflectance less than 8% 8-12% 12-15% (fine horizontal lines) 15-18% over 18%. The noisy area is so...

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