Tibesti: The Height of the Sahara

The Sahara is known from being oppressively dry and sandy, but it is certainly not uniform in appearance. When you look at a satellite image of the Sahara, you will notice a fair amount of discolouration mixed in with all of that sand – black/brown mountains of volcanic origin rising out of the desert. The world’s largest hot desert is riddled with mountains from coast to coast. You’ll notice about two-thirds of the way across the Sahara from the Atlantic to the Red Sea, and halfway between Libya’s Mediterranean coast and the Sahel, a rather large pocket of brown roughly in the shape of Tasmania. Those are the Tibesti Mountains of northern Chad.

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A closer view of the Tibesti Mountains. Notice the volcanic crater tops of some of the larger mountains.

The Tibesti Mountains massif sits upon a broad uplifted area, possibly formed by a mantle plume. Out of this uplifted area sit the seven inactive shield volcanoes that constitute the mountain range. Four of these peaks reach over 3 000 metres in elevation including the Sahara’s highest mountain, the 3 415-metre Emi Koussi, a massive shield volcano capped by a 180 km2 caldera. The climate in the Tibesti highlands is slightly wetter (though not much, around 120 mm of precipitation per year). Temperatures, however, are quite different, usually hanging around in the 10-20°C range. Terrain is steep and soils are thin, providing for a lack of vegetation in most of the Tibesti. That said, the wetter climate and cooler temperature does ensure that water persists for extended periods of time (and even year-round in some places) in the wadis and gorges that permeate the region. In these places, palms and tropical herbs flourish. Gazelles, cheetah, addax and sheep are all recorded as living in the Tibesti, and hominids dating back 3.0-to 3.5 million years before present have been found in the region.The height and ruggedness of the topography amplify winds in the area, making the region one of the windiest portions of the Sahara. These winds intensify and localise the erosional process, creating the planet’s largest single source of dust, the Bodélé Depression, formed on the ancient lakebed of Mega-Lake Chad. The depression produces enough dust to fertilise half the Amazon rainforest for a year.

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Mineral precipitate in the caldera of Emi Koussi. Photo: S. Thüngen.

The volcanic background of the Tibesti Mountains is perhaps most evident in the hot springs and geysers that can be found on and around the slopes of Soborom, the fourth-highest of the peaks (3 100 m). The springs have been used for centuries by the semi-nomadic Toubou, the indigenous inhabitants of the Tibesti. Between 350 and 400 000 Toubou live in northern Chad, with a few thousand in the northern foothills on the Libyan side of the border. Many of Chad’s leaders over the years, such as Goukouni Oueddei, Hissène Habré and Idriss Déby, were of Toubou descent, aligned and opposed to each other at various times as they fought over control of the country amongst themselves and with Libya.

Tens of thousands of landmines as well as other unexploded ordnance remain in the area 17 years after the end of the Chadian-Libyan conflict over the borderland known as the Aouzou Strip, of which the Tibesti occupies the western half. Because of the unique geologic origin of the area, there is reason to believe that there are significant uranium deposits in the region (among other minerals), making the region a valuable possession for government looking to make financial arrangement with nuclear powers. When Muammar Gaddafi took control of Libya in 1969, he immediately laid claim to the Aouzou Strip, claiming that the indigenousToubou of the area had been traditionally aligned to the Senussi order (which Gaddafi had just deposed) and thus were Libyan. Chad’s rule over the strip was based upon French occupation of the region since the aftermath of World War I. The two countries fought off-and-on for much of the 1970s and 1980s over the Aouzou Strip (and thus the Tibesti Mountains), with Libya attempting to overthrow the Chadian regime in favour the opposition, and occupy a fair amount of northern Chad at one point. This eventually ended in the so-called Toyota War of 1987, in which the various Chadian factions came together long enough to drive Libyan forces out of the country. While the conflict is long over (the International Court of Justice upheld Chadian rule in 1994), dozens of people are killed each year by buried mines, and the Tibesti is the region most affected, being at the heart of the conflict. Efforts to rid the country of mines and ordnance are progressing slowly due to the impoverished economy of the country and inaccessibility of the region. Many Toubou loyal to Gaddafi crossed over into Libya over the years, pushed into the region by continuing violence in northern Chad. Some were accepted into at-large society; others came in conflict with the government and other tribes in the area creating a fair amount of ethnic tension in southern Libya, as explained in this 2008 document given to the Telegraph by Wikileaks.

Below, an excerpt from a documentary series on the world’s deserts; the portion on the Tibesti begins at 4:41. It’s a short clip, but it does get across 1) the windiness of the area south of the Tibesti Mountains and 2) the lack of funding for education in the region. It’s a very unique place in the world with a very large role to play in African geopolitics. In light of everything going on across the border in Libya, the prospect ofseeing Tibesti popping up on the news soon is more likely than some may think.

Further Reading

Burdette, C. (2001). Tibesti-Jebel Uweinat montane xeric woodlands (PA1331). World Wildlife Fund: WildWorld. Available at http://www.worldwildlife.org/wildworld/profiles/terrestrial/pa/pa1331_full.html. Accessed 5 March 2011.

Electronic Mine Information Network (2006). Chad. Available at http://www.mineaction.org/country.asp?c=7. Accessed 5 March 2011.

Permenter, J.L. and C. Oppenheimer (2007). Volcanoes of the Tibesti massif (Chad, northern Africa). Bull Volcanol 69: 209-626. Available at http://www.geo.mtu.edu/~raman/papers2/Parmeter&OppChadBV.pdf. Accessed 5 March 2011.

U.S. Department of State (2008). Tribal violence in Kufra. 16 November 2008. Republished in The Telegraph, 31 January 2011. Available at http://www.telegraph.co.uk/news/wikileaks-files/libya-wikileaks/8294878/TRIBAL-VIOLENCE-IN-KUFRA.html. Accessed 5 March 2011.

Washington, R. et al. (2006). Links between topography, wind, deflation, lakes and dust: The case of the Bodélé Depression, Chad. Geophysical Research Letters 33: L9401. Available at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.143.7491&rep;=rep1&type;=pdf. Accessed 5 March 2011.

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