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A satellite image of the Sahara by NASA World Wind
Tadrart Acacus desert in western Libya, part of the Sahara
The top image shows the Safsaf Oasis on the surface of the Sahara. The bottom (using radar) is the rock layer underneath, revealing black channels cut by the meandering of an ancient river that once fed the oasis.

The Sahara (Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrā´ al-kubra, "The Greatest Desert") is the world's largest non-arctic desert, and technically the world's third largest desert. At over 9,000,000 square kilometres (3,500,000 sq mi), it covers most of Northern Africa, making it almost as large as the United States or the continent of Europe. The desert stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean. To the south, it is delimited by the Sahel: a belt of semi-arid tropical savanna that comprises the northern region of central and western Sub-Saharan Africa.

The Sahara has an intermittent history that may go back as much as 3 million years.[1] Some of the sand dunes can reach 180 metres (590 ft) in height.[2] The name comes from the Arabic word for desert: (صَحراء), "ṣaḥrā´" (About this sound صحراء ; [sˤɑħrɑːʔ]).[3][4]

Contents

Overview

The Sahara's boundaries are the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea and Egypt on the east, and the Sudan and the valley of the Niger River on the south. The Sahara is divided into western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Aïr Mountains (a region of desert mountains and high plateaus), Ténéré desert and the Libyan desert (the most arid region). The highest peak in the Sahara is Emi Koussi (3,415 m/11,204 ft) in the Tibesti Mountains in northern Chad.

The Sahara divides the continent of Africa into North and Sub-Saharan Africa. The southern border of the Sahara is marked by a band of semiarid savanna called the Sahel; south of the Sahel lies the lusher Sudan and the Congo River Basin. Most of the Sahara consists of rocky hamada; ergs (large sand dunes) form only a minor part.

People lived on the edge of the desert thousands of years ago[5] since the last ice age. The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles [6] survive, with half found in the Tassili n'Ajjer in southeast Algeria. Fossils of dinosaurs, including Afrovenator, Jobaria and Ouranosaurus, have also been found here. The modern Sahara, though, is not lush in vegetation, except in the Nile Valley, at a few oases, and in the northern highlands, where Mediterranean plants such as the olive tree are found to grow. The region has been this way since about 5000 years ago. Some 2.5 million people currently live in the Sahara, most of these in Egypt, Mauritania, Morocco and Algeria. Dominant ethnicities in the Sahara are various Berber groups including Tuareg tribes, various Arabised Berber groups such as the Hassaniya-speaking Maure (Moors, also known as Sahrawis), and various black African ethnicities including Toubou, Nubians, Zaghawa, Kanuri, Peul (Fulani), Hausa and Songhai. Important cities located in the Sahara include Nouakchott (the capital of Mauritania), Tamanrasset, Ouargla, Bechar, Hassi Messaoud, Ghardaia, and El Oued (Algeria), Timbuktu (Mali), Agadez (Niger), Ghat (Libya), as well as Faya-Largeau (Chad).

Geography

A geographical map of Africa, showing the ecological break that defines the Saharan area

The Sahara covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia. It is one of three distinct physiographic provinces of the African massive physiographic division.

The desert landforms of the Sahara are shaped by wind (eolian) or by occasional rains, and include sand dunes and dune fields or sand seas (erg), stone plateaus (hamada), gravel plains (reg), dry valleys (wadi), and salt flats (shatt or chott).[7] Unusual landforms include the Richat Structure in Mauritania.

Several deeply dissected mountains and mountain ranges, many volcanic, rise from the desert, including the Aïr Mountains, Ahaggar Mountains, Saharan Atlas, Tibesti Mountains, Adrar des Iforas, and the Red Sea hills. The highest peak in the Sahara is Emi Koussi, a shield volcano in the Tibesti range of northern Chad.

Most of the rivers and streams in the Sahara are seasonal or intermittent, the chief exception being the Nile River, which crosses the desert from its origins in central Africa to empty into the Mediterranean. Underground aquifers sometimes reach the surface, forming oases, including the Bahariya, Ghardaïa, Timimoun, Kufrah, and Siwah.

The central part of the Sahara is hyper-arid, with little vegetation. The northern and southern reaches of the desert, along with the highlands, have areas of sparse grassland and desert shrub, with trees and taller shrubs in wadis where moisture collects.

To the north, the Sahara reaches to the Mediterranean Sea in Egypt and portions of Libya, but in Cyrenaica and the Magreb, the Sahara borders Mediterranean forest, woodland, and scrub ecoregions of northern Africa, which have a Mediterranean climate characterized by a winter rainy season. According to the botanical criteria of Frank White[8] and geographer Robert Capot-Rey,[9][10] the northern limit of the Sahara corresponds to the northern limit of Date Palm cultivation (Phoenix dactylifera), and the southern limit of Esparto (Stipa tenacissima), a grass typical of the Mediterranean climate portion of the Maghreb and Iberia. The northern limit also corresponds to the 100 mm (3.9 in) isohyet of annual precipitation.[11]

To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with a summer rainy season that extends across Africa from east to west. The southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha (a drought-tolerant member of the Chenopodiaceae), or northern limit of Cenchrus biflorus, a grass typical of the Sahel.[9][10] According to climatic criteria, the southern limit of the Sahara corresponds to the 150 mm (5.9 in) isohyet of annual precipitation (note that this is a long-term average, since precipitation varies strongly from one year to another).[11]

An oasis in the Ahaggar Mountains. Oases are crucial to support life in very arid deserts.
An intense Saharan dust storm sent a massive dust plume northwestward over the Atlantic Ocean on March 2, 2003

Climate history

The climate of the Sahara has undergone enormous variation between wet and dry over the last few hundred thousand years.[12] During the last glacial period, the Sahara was even bigger than it is today, extending south beyond its current boundaries.[13] The end of the glacial period brought more rain to the Sahara, from about 8000 BC to 6000 BC, perhaps due to low pressure areas over the collapsing ice sheets to the north.[14]

Once the ice sheets were gone, northern Sahara dried out, But in southern Sahara, the drying trend was soon counteracted by the monsoon, which brought rain further north than it does today. The monsoon is due to heating of air over the land during summer. The hot air rises and pulls in cool, wet air from the ocean, which causes rain. Thus, though it seems counterintuitive, the Sahara was wetter when it received more insolation in the summer. This was caused by a stronger tilt in Earth's axis of orbit than today, and perihelion occurred at the end of July.[15]

By around 3400 BC, the monsoon retreated south to approximately where it is today,[16] leading to the gradual desertification of the Sahara.[17] The Sahara is now as dry as it was about 13,000 years ago.[12] These conditions are responsible for what has been called the Sahara pump theory.

The Sahara has one of the harshest climates in the world. The prevailing north-easterly wind often causes the sand to form sand storms and dust devils.[18] Half of the Sahara receives less than 20 mm (0.79 in) of rain per year, and the rest receives up to 10 cm (3.9 in) per year.[19] The rainfall happens very rarely, but when it does it is usually torrential when it occurs after long dry periods, which can last for years.

The southern boundary of the Sahara, as measured by rainfall, was observed to both advance and retreat between 1980 and 1990. As a result of drought in the Sahel, the southern boundary moved south 130 kilometres (81 mi) overall during that period.[20]. Deforestation has also caused the Sahara to advance south in recent years[citation needed], as trees and bushes continue to be used as fuel source.

Recent signals indicate that the Sahara and surrounding regions are greening due to increased rainfall. Satellites show extensive regreening of the Sahel between 1982 and 2002, and in both Eastern and Western Sahara a more than 20 year long trend of increased grazing areas and flourishing trees and shrubs has been observed by climate scientist Stefan Kröpelin.[21]

Snow and ice

For the only time in recorded weather history, snow fell in the Sahara desert in southern Algeria on February 18, 1979. The storm lasted only half an hour and the snow was gone within hours.

Ecoregions

The major topographic features of the Saharan region.

The Sahara comprises several distinct ecoregions, whose variations in temperature, rainfall, elevation, and soils harbor distinct communities of plants and animals. According to the World Wide Fund for Nature (WWF), the ecoregions of the Sahara include:

  • Atlantic coastal desert: The coastal desert occupies a narrow strip along the Atlantic coast, where fog generated offshore by the cool Canary Current provides sufficient moisture to sustain a variety of lichens, succulents, and shrubs. It covers 39,900 square kilometers (15,400 square miles) in Western Sahara and Mauritania.[22]
  • North Saharan steppe and woodlands: This ecoregion lies along the northern desert, next to the Mediterranean forests, woodlands, and scrub ecoregions of the northern Maghreb and Cyrenaica. Winter rains sustain shrublands and dry woodlands that form a transition between the Mediterranean climate regions to the north and the hyper-arid Sahara proper to the south. It covers 1,675,300 square kilometers (646,800 square miles) in Algeria, Egypt, Libya, Mauritania, Morocco, Tunisia, and Western Sahara.[23]
  • Sahara desert: This ecoregion covers the hyper-arid central portion of the Sahara where rainfall is minimal and sporadic. Vegetation is rare, and this ecoregion consists mostly of sand dunes (erg, chech, raoui), stone plateaus (hamadas), gravel plains (reg), dry valleys (wadis), and salt flats. It covers 4,639,900 square km (1,791,500 square miles) of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, and Sudan.[24]
  • South Saharan steppe and woodlands: The South Saharan steppe and woodlands occupy a narrow band running east and west between the hyper-arid Sahara and the Sahel savannas to the south. Movements of the equatorial Intertropical Convergence Zone (ITCZ) bring summer rains during July and August which average 100 to 200 mm (3.9 to 7.9 in), but vary greatly from year to year. These rains sustain summer pastures of grasses and herbs, with dry woodlands and shrublands along seasonal watercourses. The ecoregion covers 1,101,700 km2 (425,400 mi2) in Algeria, Chad, Mali, Mauritania, and Sudan.[25]
  • West Saharan montane xeric woodlands: Several volcanic highlands in the western portion of the Sahara provide a cooler, moister environment that supports Saharo-Mediterranean woodlands and shrublands. The ecoregion covers 258,100 km2 (99,700 mi2), mostly in the Tassili n'Ajjer of Algeria, with smaller enclaves in the Aïr of Niger, the Dhar Adrar of Mauritania, and the Adrar des Iforas of Mali and Algeria.[26]
  • Tibesti-Jebel Uweinat montane xeric woodlands: The Tibesti and Jebel Uweinat highlands foster higher, more regular rainfall and cooler temperatures, which support woodlands and shrublands of palms, acacias, myrtle, oleander, Tamarix, and several rare and endemic plants. The ecoregion covers 82,200 km2 (31,700 mi2) in the Tibesti of Chad and Libya, and Jebel Uweinat on the border of Egypt, Libya, and Sudan.[27]
  • Saharan halophytics: Seasonally-flooded saline depressions in the Sahara are home to halophytic, or salt-adapted, plant communities. The Saharan halophytics cover 54,000 km2 (20,800 mi2), including the Qattara and Siwa depressions in northern Egypt, the Tunisian salt lakes of central Tunisia, Chott Melghir in Algeria, and smaller areas of Algeria, Mauritania, and Western Sahara.[28]
  • Tanezrouft: One of the harshest regions on Earth and the driest in the Sahara, contains no vegetation and very little life.

Fauna

Shadows of camels with travelers on dunes in Tunisia
  • Dromedary camels and goats are the most domesticated animals found in the Sahara. Because of its qualities of endurance and speed, the dromedary is the favorite animal used by nomads.
  • The Leiurus quinquestriatus (aka deathstalker) scorpion which can be 10 cm (3.9 in) long. Its venom contains large amounts of agitoxin and scyllatoxin and is very dangerous; however, a sting from this scorpion rarely kills a healthy adult.
  • The monitor lizard. It has been suggested that the occasional habit of varanids to stand on their two hind legs and to appear to "monitor" their surroundings led to the original Arabic name waral ورل, which is translated to English as "monitor".[29]
  • Sand vipers, which average less than 50 cm (20 in) in length. Many have a pair of horns, one over each eye. Active at night, they usually lie buried in the sand with only their eyes visible. Bites are painful, but rarely fatal.
  • The African Wild Dog has some populations confirmed[citation needed] in the southern Sahara and is frequently misidentified as the cryptid Adjule.
  • The fennec fox, pale fox and Rüppell's fox, are omnivorous canids living in many parts of Sahara.
  • The hyrax. It first appears in the fossil record over 40 million years ago, and for many millions of years hyraxes were the primary terrestrial herbivore in Africa.
  • The ostrich which is a flightless bird native to Africa. They have become rare.
  • The addax, a large white antelope, is a threatened species. Adapted to the desert, they can remain months without drinking, even a whole year.
  • The Saharan cheetah lives in Algeria, Togo, Niger, Mali, Benin, and Burkina Faso. There remain less than 250 mature cheetahs which are very cautious, fleeing any human presence. The cheetah avoids the sun from April to October. It then seeks the shelter of shrubs such as balanites and acacias. They are unusually pale.[30][31]
  • The dorcas gazelle is a north African gazelle that can also go for a long time without water.

There exist other animals in the Sahara (birds in particular) such as African Silverbill and Black-throated Firefinch among others.

History

Photo of the Sahara from 1908

Berbers

Berbers are one of the oldest known inhabitants of the Sahara Desert.[citation needed] They are the people that occupied (and still occupy) more than two thirds of the Sahara's total surface.[citation needed]The Garamantes Berbers built a prosperous empire in the heart of the desert.[citation needed] The Tuareg nomads continue, to present day, to inhabit and move across wide Sahara surfaces in Algeria, Mali, Niger, Mauritania, and Libya. Some of the oldest Berber Tifinagh inscriptions are found in Southern Algeria, Northern Mali and Niger.[citation needed]

Egyptians

By 6000 BC predynastic Egyptians in the southwestern corner of Egypt were herding cattle and constructing large buildings. Subsistence in organized and permanent settlements in predynastic Egypt by the middle of the 6th millennium BC centered predominantly on cereal and animal agriculture: cattle, goats, pigs and sheep. Metal objects replaced prior ones of stone. Tanning of animal skins, pottery and weaving are commonplace in this era also.[32] There are indications of seasonal or only temporary occupation of the Al Fayyum in the 6th millennium BC, with food activities centering on fishing, hunting and food-gathering. Stone arrowheads, knives and scrapers are common.[33] Burial items include pottery, jewelry, farming and hunting equipment, and assorted foods including dried meat and fruit. Burial in desert environments appears to enhance Egyptian preservation rites, and dead are buried facing due west.[32] By 3400 BC, the Sahara was as dry as it is today, and it became a largely impenetrable barrier to humans, with only scattered settlements around the oases, but little trade or commerce through the desert. The one major exception was the Nile Valley. The Nile, however, was impassable at several cataracts, making trade and contact by boat difficult.

A Saharan village in Mali

Nubians

During the Neolithic, before the onset of desertification, around 9500 BC the central Sudan had been a rich environment supporting a large population ranging across what is now barren desert, like the Wadi el-Qa'ab. By the 5th millennium BC, the peoples who inhabited what is now called Nubia, were full participants in the "agricultural revolution," living a settled lifestyle with domesticated plants and animals. Saharan rock art of cattle and herdsmen found suggests the presence of a cattle cult like those found in Sudan and other pastoral societies in Africa today.[34] Megaliths found at Nabta Playa are overt examples of probably the world's first known Archaeoastronomy devices, predating Stonehenge by some 1000 years.[35] This complexity, as observed at Nabta Playa, and as expressed by different levels of authority within the society there, likely formed the basis for the structure of both the Neolithic society at Nabta and the Old Kingdom of Egypt.[36]

Phoenicians

The peoples of Phoenicia, who flourished between 1200-800 BC, created a confederation of kingdoms across the entire Sahara to Egypt. They generally settled along the Mediterranean coast, as well as the Sahara, among the peoples of Ancient Libya, who were the ancestors of peoples who speak Berber languages in North Africa and the Sahara today, including the Tuareg of the central Sahara.

The Phoenician alphabet seems to have been adopted by the ancient Libyans of north Africa, and Tifinagh is still used today by Berber-speaking Tuareg camel herders of the central Sahara.

Sometime between 633 BC and 530 BC, Hanno the Navigator either established or reinforced Phoenician colonies in Western Sahara, but all ancient remains have vanished with virtually no trace. (See History of Western Sahara.)

An Algerian man in urban dress
The 12th Century traveller Benjamin of Tudela in the Sahara (Dumouza, 19th Century engraving)

Greeks

By 500 BC, a new influence arrived in the form of the Greeks. Greek traders spread along the eastern coast of the desert, establishing trading colonies along the Red Sea coast. The Carthaginians explored the Atlantic coast of the desert. But the turbulence of the waters and the lack of markets never led to an extensive presence further south than modern Morocco. Centralized states thus surrounded the desert on the north and east; it remained outside the control of these states. Raids from the nomadic Berber people of the desert were a constant concern of those living on the edge of the desert.

Urban civilization

An urban civilization, the Garamantes, arose around this time in the heart of the Sahara, in a valley that is now called the Wadi al-Ajal in Fazzan, Libya.[12] The Garamantes achieved this development by digging tunnels far into the mountains flanking the valley to tap fossil water and bring it to their fields. The Garamantes grew populous and strong, conquering their neighbors and capturing many slaves (which were put to work extending the tunnels). The ancient Greeks and the Romans knew of the Garamantes and regarded them as uncivilized nomads. However, they traded with the Garamantes, and a Roman bath has been found in the Garamantes capital of Garama. Archaeologists have found eight major towns and many other important settlements in the Garamantes territory. The Garamantes civilization eventually collapsed after they had depleted available water in the aquifers, and could no longer sustain the effort to extend the tunnels still further into the mountains.[37]

Trans-Saharan trade

Following the Islamic conquest of North Africa in the mid-seventh to early eighth centuries, trade across the desert intensified. The kingdoms of the Sahel, especially the Ghana Empire and the later Mali Empire, grew rich and powerful exporting gold and salt to North Africa. The emirates along the Mediterranean Sea sent south manufactured goods and horses. From the Sahara itself, salt was exported. This process turned the scattered oasis communities into trading centres, and brought them under the control of the empires on the edge of the desert. A significant slave trade crossed the desert (See Arab slave trade).

This trade persisted for several centuries until the development in Europe of the caravel allowed ships, first from Portugal but soon from all Western Europe, to sail around the desert and gather the resources from the source in Guinea. The Sahara was rapidly remarginalized.

European imperialism

At the beginning of the 19th century, most of the northern Sahara, including most of present-day Algeria, Tunisia, Libya, and Egypt, was part of the Ottoman Empire. The Sahel and southern Sahara were home to several independent states.

European colonialism in the Sahara began in the 19th century. France conquered Algeria from the Ottomans in 1830, and French rule spread south from Algeria and eastwards from Senegal into the upper Niger to include present-day Algeria, Chad, Mali, Mauritania, Morocco (1912), Niger, and Tunisia (1881).

Egypt, under Muhammad Ali and his successors, conquered Nubia (1820-22), founded Khartoum (1823), and conquered Darfur (1874). Egypt, including the Sudan, became a British protectorate in 1882. Egypt and Britain lost control of the Sudan from 1882 to 1898 as a result of the Mahdist War. After its capture by British troops in 1898, the Sudan became a Anglo-Egyptian condominium.

Spain captured present-day Western Sahara after 1874. In 1912, Italy captured Libya from the Ottomans.

To promote the Roman Catholic religion in the desert, the Pope in 1868 appointed a delegate Apostolic of the Sahara and the Sudan; later in the 19th century his jurisdiction was reorganized into the Vicariate Apostolic of Sahara.

Modern times

A natural rock arch in south western Libya

Egypt became independent of Britain in 1936, although the Anglo-Egyptian Treaty of 1936 allowed Britain to keep troops in Egypt and maintained the British-Egyptian condominium in the Sudan. British military forces were withdrawn in 1954.

Most of the Saharan states achieved independence after World War II: Libya in 1951, Morocco, Sudan, and Tunisia in 1956, Chad, Mali, Mauritania, and Niger in 1960, and Algeria in 1962. Spain withdrew from Western Sahara in 1975, and it was partitioned between Mauritania and Morocco. Mauritania withdrew in 1979, but Morocco continues to hold the territory.

The modern era has seen a number of mines and communities develop to exploit the desert's natural resources. These include large deposits of oil and natural gas in Algeria and Libya and large deposits of phosphates in Morocco and Western Sahara.

A number of Trans-African highways have been proposed across the Sahara, including the Cairo-Dakar Highway along the Atlantic coast, the Trans-Sahara Highway from Algiers on the Mediterranean to Kano in Nigeria, the Tripoli-Cape Town Highway from Tripoli in Libya to Ndjamena in Chad, and the Cairo-Cape Town Highway which follows the Nile. Each of these highways is partially complete, with significant gaps and unpaved sections.

Peoples and languages

The Sahara is home to a number of people and languages. Arabic is the most widely spoken language in the Sahara, from the Atlantic to the Red Sea. Berber people are found from western Egypt to Morocco, including the Tuareg pastoralists of the central Sahara. The Beja live in the Red Sea Hills of southeastern Egypt and eastern Sudan. The Arabic, Berber, and Beja languages are part of the Afro-Asiatic language family.

Speakers of the Nilo-Saharan language family also inhabit the Sahara, including the Fur of Darfur in western Sudan and the Saharan languages of Niger, Chad and western Sudan, which includes the Kanuri, Tedaga, and Dazaga.

See also

References

Notes

  1. ^ MIT OpenCourseWare. (2005) "9-10 thousand Years of African Geology". Massachusetts Institute of Technology. Pages 6 and 13
  2. ^ Arthur N. Strahler and Alan H. Strahler. (1987) Modern Physical Geography–Third Edition. New York: John Wiley & Sons. Page 347
  3. ^ "Sahara." Online Etymology Dictionary. Douglas Harper, Historian. Accessed on June 25, 2007.
  4. ^ English-Arabic online dictionary
  5. ^ Discover Magazine, 2006-Oct.
  6. ^ National Geographic News, 2006-06-17.
  7. ^ "Sahara desert" WWF Scientific Report [1]. Accessed December 30, 2007.
  8. ^ Wickens, Gerald E. (1998) Ecophysiology of Economic Plants in Arid and Semi-Arid Lands. Springer, Berlin. ISBN 978-3-540-52171-6
  9. ^ a b Grove, A.T., nicole (1958,2007). "The Ancient Erg of Hausaland, and Similar Formations on the South Side of the Sahara". The Geographical Journal 124 (4): 528–533. doi:10.2307/1790942. http://links.jstor.org/sici?sici=0016-7398(195812)124%3A4%3C528%3ATAEOHA%3E2.0.CO%3B2-3. Retrieved 2007-05-23. 
  10. ^ a b Bisson, J. (2003). Mythes et réalités d'un désert convoité: le Sahara. L'Harmattan. (French)
  11. ^ a b Walton, K. (2007). The Arid Zones. Aldine. 
  12. ^ a b c Kevin White and David J. Mattingly (2006), Ancient Lakes of the Sahara, 94, American Scientist, pp. 58–65 
  13. ^ Christopher Ehret. The Civilizations of Africa. University Press of Virginia, 2002.
  14. ^ Fezzan Project — Palaeoclimate and environment, retrieved March 15, 2006.
  15. ^ "Geophysical Research Letters" Simulation of an abrupt change in Saharan vegetation in the mid-Holocene - July 15th, 1999
  16. ^ Sahara's Abrupt Desertification Started by Changes in Earth's Orbit, Accelerated by Atmospheric and Vegetation Feedbacks.
  17. ^ Kröpelin, Stefan; et al. (2008). "Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years". Science 320 (5877): 765–768. doi:10.1126/science.1154913. PMID 18467583. 
  18. ^ Oxfam Cool Planet - the Sahara - access February 10, 2008
  19. ^ Tiempo Climate Newswatch: Climate Change and the Sahara
  20. ^ Expansion and contraction of the Sahara Desert between 1980 and 1990| Science 253: 299-301.
  21. ^ Sahara Desert Greening Due to Climate Change?
  22. ^ "Atlantic coastal desert" WWF Scientific Report [2]. Accessed December 29, 2007.
  23. ^ "North Saharan steppe and woodlands" WWF Scientific Report [3]. Accessed December 29, 2007.
  24. ^ "Sahara desert" WWF Scientific Report [4]. Accessed December 29, 2007.
  25. ^ "South Saharan steppe and woodlands" WWF Scientific Report [5]. Accessed December 29, 2007.
  26. ^ "West Saharan montane xeric woodlands" WWF Scientific Report [6]. Accessed December 29, 2007.
  27. ^ "Tibesti-Jebel Uweinat montane xeric woodlands" WWF Scientific Report [7]. Accessed December 29, 2007.
  28. ^ "Saharan halophytics" WWF Scientific Report [8]. Accessed December 29, 2007.
  29. ^ Pianka, E.R.; King, D.R. and King, R.A. 2004. Varanoid Lizards of the World. Indiana University Press.
  30. ^ http://news.bbc.co.uk/2/hi/science/nature/7905986.stm BBC News: " Rare cheetah captured on camera"
  31. ^ http://www.iucnredlist.org/apps/redlist/details/221/0/full The IUCN Red List of Threatened Species: Acinonyx jubatus ssp. hecki
  32. ^ a b Predynastic] (5,500–3,100 BC), Tour Egypt].
  33. ^ Fayum, Qarunian (Fayum B, about 6000–5000 BC?), Digital Egypt.
  34. ^ History of Nubia
  35. ^ PlanetQuest: The History of Astronomy - Retrieved on 2007-08-29
  36. ^ Late Neolithic megalithic structures at Nabta Playa - by Fred Wendorf (1998)
  37. ^ Keys, David. 2004. Kingdom of the Sands. Archaeology. Volume 57 Number 2, March/April 2004. Abstract retrieved March 13, 2006.

Bibliography

  • Michael Brett and Elizabeth Frentess. The Berbers. Blackwell Publishers, 1996.
  • Charles-Andre Julien. History of North Africa: From the Arab Conquest to 1830. Praeger, 1970.
  • Abdallah Laroui. The History of the Maghrib: An Interpretive Essay. Princeton, 1977.
  • Hugh Kennedy. Muslim Spain and Portugal: A Political History of al-Andalus. Longman, 1996.
  • Richard W. Bulliet. The Camel and the Wheel. Harvard University Press, 1975. Republished with a new preface Columbia University Press, 1990.

External links


Quotes

Up to date as of January 14, 2010
(Redirected to Sahara (film) article)

From Wikiquote

Sahara is a 2005 film directed by Breck Eisner and based on the best-selling book of the same name by Clive Cussler. The film follows Master explorer and former US Navy Seal Dirk Pitt and his wisecracking buddy Al Giordino goes on the adventure of a lifetime of seeking out a lost Civil War ironclad battleship known as the "Ship of Death" that protects a secret cargo is lost somewhere in the deserts of West Africa.

Contents

Dirk Pitt

  • (to Eva as Al, Dirk and Eva are being pursued in Kazim's car) I hope you don't throw like a girl!

Al Giordino

  • Hi! How are ya?
  • I am so tired of being shot at!
  • (in the stolen car, being chased by a chopper) It's Kazim! Hey, maybe he wants his car back?

Eva Rojas

  • (as Kazim's troops lay down their weapons in surrender) Looks like you killed the snake.

Admiral James Sandecker

  • Don't you hurt my boat.

General Zateb Kazim

  • Don't worry. It's Africa. Nobody cares about Africa.

Dialogue

Rudi: What's a Panama?

Al: Navy thing.

Rudi: I didn't know you were in Panama.

Al: We wern't, we were in Nicaragua.

Rudi: So, why do you call it a Panama?

Al: We thought we were in Panama!

Sandecker:(On the phone) NO PANAMA!


Al: Next time you go!

Dirk: What the hell took you so long?

AL: What? I stopped for coffee.

Dirk: Did you get a receipt?

Al: Yeah, I got a receipt, and you know what? I got you one too!

Dirk: You're the best Al!

Al: You know what? I'll even get you the money from Sandecker.


Al: I'm so sick of being shot at!!


Rudi: But,I was hoping to meet a girl on the australian trip.

Al: No. African war zone, ship of death!


Dirk: What would you do if you were about to be exposed as the biggest polluter in history?

Al: I don't know. Run for president?


Al: What do you think, Dirk?

Dirk: Uh, I think we need to pull a Panama.

Al: A Panama? A PANAMA?!

Sandecker: Panama?


Dirk: Al, did you get the explosives from Massardes?

Al: Couldn't find them.

Dirk: Al...

Al: Didn't have time.

Dirk: AL!

Al: Of course I brought the explosives!


Dirk: I'm sorry I don't speak English.

Gunboat Officer: You are speaking English right now.

Dirk: No, I only know how to say, "I don't speak English" in English.


Dirk: Hey Al, Do remember that time when we were in Morocco?

Al: Ya, when you made me ride that damn camel, that bit my ass.

Dirk: Yeah, that's the time.

Al: Why?


Rudi: I shot a Guy with a flare gun.



Al: Hey, you know how it is when you see someone that you haven't seen since high school, and they got some dead-end job, and they're married to some woman that hates them, they got three kids who, like, think he's a joke? Wasn't there some point where you stood back and said, "Bob, don't take that job! Bob, don't marry that harpy!" You know?

Dirk: Your point?

Al: Well, we're in the desert, looking for the source of a river pollutant, using as our map a cave drawing of a Civil War gunship, which is also in the desert. So I was just wondering when we're gonna have to sit down and re-evaluate our decision-making paradigm?

Dirk: (seeing the old fort from the cave painting) I don't know. It seems to be working so far.


Al: Hey, I cant remember how this works... something about a fox and a rabbit... its really bugging me.


Travel guide

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Africa : Saharan Africa
Contents

Saharan Africa is a region of Africa.

Countries of Saharan Africa
Countries of Saharan Africa
Chad
Mali
Mauritania
Niger
Sudan
The Sahara
The Sahara

Cities

There is a very low population in this area of Africa and cities and rare and far between but in order here are the main ones.

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1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

SAHARA, the great desert of northern Africa. The Sahara has an area, according to Dr A. Bludau's calculation of the areas of African river basins, of 3,459,500 sq. m., made up as follows: - Sq. m. Drainage or slope to Atlantic.. 131,000131,000 Drainage or slope to Mediterranean. 502,000 Drainage inland.. 2,602,500 Slope to Niger basin. 224,000 Area and has almost the appearance of a boundless sea, and bound- aries. forms, as it were, a bold coast-line, whose sheltered bays and commanding promontories are occupied by a series of towns and villages - Tizgi, Figuig, El Aghuat, &c. In other directions the boundaries are vague, conventional and disputed. This is especially the case towards the south, where the desert sometimes comes to a close as suddenly as if it had been cut off with a knife, but at other times merges gradually and irregularly into the well-watered and fertile lands of the Sudan. While towards the east the valley of the Nile at first sight seems to afford a natural frontier, the characteristics of what is usually called the Nubian desert are so identical in most respects with those of the Sahara proper that some authorities extend this designation to the shores of the Red Sea. The desert, indeed, does not end with Africa, but is prolonged eastwards through Arabia towards the desert of Sind. As the Nubian region is described under Sudan: § Anglo-Egyptian, the present article is confined to the country west of the Nile Valley, the Libyan desert inclusive. Its greatest length, along the 10th parallel of north latitude, is some 3200 m.; its breadth north to south varies from Boo to 1400 M.

The sea-like aspect of certain portions of the Sahara has given rise to much popular misconception, and has even affected the ideas and phraseology of scientific writers. Instead of General . being a boundless plain broken only by wave-like aspect The Ahaggar plateau is not inferior to the Alps in area, but its highest peaks do not greatly exceed 8000 ft. They are believed to be volcanic like those of Auvergne. Upon their summits snow is reputed to lie from December to March. South-east of the main plateau, and partly filling the valley between the Ahaggar plateau and the Tasili of the Asjer (see infra), are the Anahef mountains. To the north the valley is again contracted by the Irawen mountains.

Besides this central group of mountains, sometimes spoken of as the Atakor-'n-Ahaggar (Summits of the Ahaggar), there are various other massifs in the Sahara. On the north-west of the Mountain Ahaggar, and separated from it by a wide plain, is the Muidir plateau, which extends nearly east and west 200 m. ranges. North-east of the Ahaggar (in the direction of Tripoli) is the Tasili of the Asjer (4000-5000 ft.), which runs for 300 m. in a N.E. to S.E. direction. South-east of the Tasili of the Asjer is a range of hills known as the Tummo (or War) mountains. Still farther south is the mountainous region of Tibesti (or Tu), with an average height of some 7000 ft., the volcanic cone of Tussid rising to an estimated height of 8800 ft. Towards the south and east the Tibesti highlands are connected with the lower ranges of Borku and Ennedi, which merge into the plains of Wadai and Darfur. The slopes are bare and rocky. By some authorities the Tasili of the Asjer, the Tummo, Tibesti and Borku ranges are considered " the orographic backbone " of the Sahara.

In addition to the plateaus and ranges named, there are several disconnected mountain masses. Midway between the Atakor-'nAhaggar and Nigeria are the Air or Asben hills in which Dr Erwin von Bary discovered (1877) the distinct volcanic crater of Teginjir with a vast lava-bed down its eastern side. By some writers Air (q.v.) is not included in the Sahara, as it lies within the limit of the tropical rains; but the districts farther south have all the characteristics of the desert. West of Air, and north-east of the bend of the Niger, lies the hilly region sometimes known as Adrar of the Iforas or of the Awellimiden (the southern confederacy of the Tuareg). To the N.E., in Fezzan, are the dark mountains of Jebel-esSoda, which are continued S.E. towards Kufra by the similar range of the Haruj; and in the extreme S.W., at no great distance from the Atlantic, is the hilly country of the western Adrar (q.v.).

Nearly all the rest of the Sahara consists in the main of undulating surfaces of rock (distinguished as hammada), vast tracts of waterworn pebbles (serir) and regions of sandy dunes (variously called maghter, erg or areg, igidi, and in the east rhart), which occupy about one-ninth or one-tenth of the total area. The following is the general distribution of the dunes: From a point on the Atlantic coast south of Cape Blanco a broad belt extends N.E. for about 1300 m., with a breadth varying from 50 to 300 m. This is usually called the Igidi or Gidi, Sand from the Berber word for dunes. In part it runs parallel dunes. with the Atlas mountains. Eastward it is continued, south of Algeria and Tunisia, by the Western Erg and Eastern Erg, separated by a narrow valley at Golea. South of the Eastern Erg (which extends as far north as the neighbourhood of the Gulf of Gabes) the continuity of the sandy tract is completely broken by the Hammada al-Homra (or Red Rock Plateau), but to the south of this region lie the dunes of Edeyen, which, with slight interruptions, extend to Murzuk in Fezzan. South of the hammada of Murzuk the dunes of Murzuk stretch south-east. This series of tracts may be called the northern zone of the Sahara; it forms a kind of bow, with its extremities respectively at the Atlantic and the Libyan desert and its apex in the south of Tunisia. In the south are the Juf (depressions), covering a vast area to the south-east of the middle portion of the Igidi, another area between the Adghagh plateau and the Ahaggar, and a third between Air and Tibesti. The Juf or depressions are not, except in rare instances, below sealevel. In the Libyan desert is a vast region of dunes of unascertained limits; the characteristics of the Libyan desert being thought typical of the whole of the Sahara originated the idea of " a sea of shifting sand " as descriptive of the entire desert. Here a region of over 500,000 sq. m. extending east from the Tibesti mountains to the valley of the Nile, bounded south by Wadai and Darfur and north by Fezzan and the Cyrenaica, appears to be almost entirely sterile and increasingly covered by dunes. There is only one known route through this dreadful wilderness - one running north and south to the oases of Kufra, which lie in its centre. The dunes in the Libyan desert, so far as is known, run N.N.W. and S.S.E. In the Eastern Erg the dunes also lie in long lines in a N.N.W. and S.S.E. direction, presenting a gradual slope to windward and an abrupt descent to leeward. There they are generally about 60 or 70 ft. high, but in other parts of the Sahara they are said to attain a height of upwards of 300 ft.

Under the influence of the wind the surface of the dunes is subject to continual change, but in the mass they have attained such a state of comparative equilibrium that their topographic distribution may be considered as permanent, and some of them, such as Gern (Peak) al-Shuf and Gern Abd-al-Kader, to the south of Golea, have names of their own. The popular stories about caravans and armies being engulfed in the moving sands are regarded as apocryphal (save perhaps in some instances in the Libyan desert), but there is abundant Total.. 3,459,500 This includes Tripoli and Fezzan, which practically belong to the desert zone, but does not include arid portions of the basins of the Nile and Niger, in which the drainage is at most intermittent, and which might with reason be included in the Sahara. The area would thus be brought up to at least 31 million sq. m., about the area of Europe minus the Scandinavian peninsula.

The physical limits of this region are in some directions marked with great precision, as in parts of Morocco and Algeria, where the southern edge of the Atlas range looks out on what mounds of sand hardly more stable than the waves of ocean, the Sahara is a region of the most varied surface and irregular relief, ranging from 100 ft. below to 5000 and 6000 and even in isolated instances to 8000 ft. above the sealevel, and, besides sand-dunes and oases, containing rocky plateaus, vast tracts of loose stones and pebbles, ranges of the most dissimilar types, and valleys through which abundant watercourses must once have flowed.

In the centre of the Sahara is a vast mountain region known as the Ahaggar (Hoggar) Tasili or plateau. The culminating peaks of this plateau. Mounts Watellen and Hikena, are about 900 m. in a straight line almost due S. of the city of Algiers and about 1200 m. due N. of the mouth of the Niger. They also occupy, speaking roughly, a central position between the Atlantic and the Nile.

evidence against the theory of M. Vatonne as to the dunes having been formed in situ. Although now mainly waterless, the Sahara possesses the skeleton of a regular river-system. From the north side of the Atakor-'n Ahaggar, through which runs the " water-parting " raver- between the basins of the Mediterranean and Atlantic,. begins Wadi Igharghar, which, running northwards between the Tasili plateau and the Irawen mountains, appears to lose itself in the sands of the Eastern Erg, but can be traced northwards for hundreds of miles. Its bed contains rolled fragments of lava and freshwater shells (Cyrena and Planorbis). In a line almost parallel to Wadi Igharghar, Wadi Mya descends from the plateau of Tademayt, and shows the importance of its ancient current by deep erosion of the Cretaceous rocks, in which a large number of left-hand tributaries have also left their mark. The streams flowing south from the Atlas, which seem to be absorbed in the sands of the desert, evidently find a series of underground reservoirs or basins capable of being tapped by artesian wells over very extensive areas. As Olympiodorus (quoted by Photius) mentions that the inhabitants of the Sahara used to make excavations from 100 to 120 ft. deep, out of which jets of pure water rose in columns, it is clear that this state of matters is (historically) of ancient date. Since 1856 French engineers have carried on a series of borings which have resulted in the fertilizing of extensive tracts. In Wadi Righ (otherwise Rhir), which runs for 80 m. towards the south-west of the Shat Melrir (department of Constantine, Algeria), the water-bearing stratum is among permeable sands, which are covered to a depth of 200 ft. by impermeable marls, by which the water is kept under pressure. In this valley many artesian wells have been sunk by the French. Connexions probably exist with subterranean water-supplies in the mountains to the north. That the water in the artesian reservoirs is kept aerated is shown by the existence below ground of fishes, crabs and freshwater molluscs, all of which were ejected by the well called Mezer in Wadi Righ. Further west the Wadis Zusfana and Ghir unite to form the Saura, known in Tuat as the Messaud. These rivers still carry water as far as the northern part of Tuat; thence the course of the Messaud was, apparently, S.W. to the eastern Juf. There are also wellmarked river-beds in the central [Sahara. The Wadi Telemsi, rising in Adrar, of the Iforas, apparently joined the Niger near Gao, while the Wadi Taffassassent, which rose in the Ahaggar mountains, is believed to have been the ancient upper course of the lower Niger. The oases are also proofs of the presence of a steady supply of underground moisture, for vegetation under the Saharan climate (beyond the few plants specially adapted to desert conditions) is exceptionally thirsty.

The existence of these wadis or river-beds is a factor in the consideration of the cause of the desert nature of the country. In all parts of the Sahara there is evidence of denudation carried out on a scale of unusual magnitude. The present surface n of the desert has been exposed to the protracted wear and tear of the elements. But to determine the exact method by which the elements have done their work has hitherto proved beyond the power of science. The theory of submarine denudation was accepted by many scientists of the mid-Victorian era. The sand-dunes, the salt efflorescence and deposits, and the local occurrence of certain modern marine molluscs all go to help the hypothesis of a diluvial sea. Nor is evidence lacking that in cretaceous times portions of the Sahara were covered by the sea. Colonel P. L. Monteil brought home (1892) a fossil sea-urchin from Bilma. In 1902 at Tamaske, some 250 m. W. of Zinder, and a little north of Sokoto, a nautilus and four sea-urchins (fossils) were found by Captain Gaden in a limestone bed. Similar fossils occur in the region between Zinder and Air, and others of the same age have been found near Dakar. Basing his conclusions on these and other facts, de Lapparent held that an arm of the sea extended inland from the Atlantic to the eastern Sahara. This sea was bounded on the north and east by the mountains of Air, Ahaggar, the Asjer Tasili, &c. An extensive acquaintance with Saharan characteristics shows, however, that a sea for the Sahara as a whole is impossible. Henri Schirmer, who in 1893 published an admirable summary of Saharan geography up to that date, argued that the desert nature of the Sahara is due to forces which have been at work for ages, although, as in all deserts, the dryness is probably progressively increasing. The primary cause is to be sought in the existing distribution of land and sea, the great land mass of North Africa causing an outflow of air in all directions (and consequent absence of rain) in winter, and an indraught in summer, when the surface is intensely heated and the relative humidity of the atmosphere becomes so small that condensation is all but impossible. The vicinity of the comparatively cool Mediterranean in the north accentuates the (once of the winds from that direction, which, blowing towards a lower latitude, are in their very nature dry winds. The influence of mountain ranges, such as the Atlas, round the border of the desert, is thus but a subordinate cause of the latter's dryness, which would probably be little diminished did the Atlas not exist. This dryness reacts again on the temperature conditions of the Sahara, accentuating both the daily and annual variation. The intense heat of the day is compensated by the cold of the nights, so that the mean annual temperature is not excessive. The difference between the mean temperature of the hottest and coldest month has been found to be as high as 45° F., and the extreme range at least 90° F., maxima of 112 and over having been frequently observed. As a result of the extreme dryness of the air, evaporation is excessive, and, being greater than the precipitation, involves a progressive desiccation of the Sahara. The surface of the rocks, heated by the sun and suddenly chilled by rapid radiation at night, gets fractured and crumbled; elsewhere the cliffs have been scored and the sand thus formed is at once turned by the wind into an active instrument of abrasion. 1n many places it has planed the flat rocks of the hammada as smooth as ice. Elsewhere it has scored the vertical faces of the cliffs with curious imitations of glacial striation, and helped to undercut the pillar or table-like eminences - remains of former more extensive plateaus - which, under the name gur, are among the most familiar products of Saharan erosion. The softer quartz rocks of the Quaternary and Cretaceous series have been made to yield the sand which, drifted and sifted by the winds, has taken on the form of dunes. The slighest breeze is enough to make the surface " smoke " with dust; and at times the weird singing of the sands, waxing louder and louder, tells the scientific traveller that the motion is not confined to the superficial particles. The dry wind of the Sahara is known in southern Europe as the Sirocco. It brings with it clouds of fine red dust, as noted long since by Idrisi, the Arabian geographer. Dr Theobald Fischer and Dr Oscar Fraas agree in believing that the desiccation has markedly increased in historic times. Evidence derived from ancient monuments combined with the statements of Herodotus and Pliny are held to prove that the elephant, the rhinoceros, and the crocodile existed in North African regions where the environment is now utterly alien, and on the other hand that the camel is a late introduction.

Any attempt to improve the climatic conditions of the Sahara as a whole can hardly meet with success when the causes of its desiccation are considered. Much may, however, be done to modify local conditions, and fairly satisfactory results have been obtained in the direction of fixing the dunes and covering them with a growth of vegetation. Experiments carried out by the French at Ain Sefra, on the northern border of the desert, have shown that by protecting the sand from the action of the wind by a litter of alfa grass, time is given for the establishment of suitable trees, which include the tamarisk, acacia, eucalyptus, prickly pear, peach and aspen poplar, the last-named having proved the most capable of all of resisting the desert conditions. Such planting operations can only be carried out in favourable localities, such as valleys in which a certain amount of water is available. Wide areas like the arid stony plateaus (hammada) must be abandoned as hopeless.

As already stated, the popular conception of the Sahara as a sand desert is erroneous. It is really a stony, wind-swept waste with much bare rock visible, the actual area of pure sand forming a relatively small portion. A broad belt of Archaean rocks extends throughout the desert, appearing at intervals in the form of hills and plateaus from beneath the superficial sands and Quaternary deposits, Examples are the granite of Air and the gneiss and mica-schists of this massif and of the Ahaggar plateau. Flanking this zone are immense tracts occupied by rocks of Devonian and Carboniferous ages, from which characteristic marine fossils have been obtained at the springs of El Hassi and between Wad Draa and the dunes of Igidi. Productus africanus is a common fossil of the Carboniferous rocks. At the close of the Carboniferous period it has been generally considered that the southern and central Sahara became dry land and has remained so up to the present day. Marine fossils of Cretaceous age have, however, been found within recent years in the central regions; while Eocene echinoids have been obtained near Sokoto (Geol. Mag., 1904). During Lower Cretaceous times the Mediterranean covered the Algerian and Tripolitan Sahara and the northern portion of the eastern desert; the extensive development of the Cretaceous system being one of the most striking features of Saharan geology. At the close of the Cretaceous period the Tripolitan Sahara completely emerged, but parts of the Tunisian and Algerian Sahara seem to have remained below sea-level until the end of the Lower Eocene. Only on the extreme borders of the desert, however, do tertiary formations play any prominent part. During the Quaternary period the Sahara possessed a moister climate than the present. This is shown by the numerous water-cut valleys, now dry, and by the remains of hippopotamus in the Quaternary deposits.

The idea so long held that the Sahara represented the recently dried-up bed of an extension of the Mediterranean has been disproved by the investigations of French geologists. The sand is mainly derived from the wide expanse of Cretaceous sandstones, which become rapidly disintegrated by the contraction caused by the wide range of temperature between day and night. The loose sands of the Quaternary deposits also furnish abundant material. The true dune sand is remarkable for the uniformity of its composition and the geometrical regularity of its grains, which measure less than .03937 in. While individually these appear transparent or reddish yellow (from the presence of iron), they have in the mass a rich golden hue. According to Tissandier animal organisms, such as the microscopic shells of Rhizopoda, abundant in sea-sand, are strikingly absent.

Botanically the Sahara is the meeting-ground of representatives of the " Mediterranean " and the " Tropical " floras which have accommodated themselves to the peculiar climatic conditions. "I'he line of demarcation between the two floral areas, almost coinciding in the west with the Tropic of Cancer and in the east Botany and by far the greater portion of the a ea to I " Mediterranean d?ns Zoology. influences. Uniformity, in spite of differences of altitude and soil, is a general characteristic of the vegetation, which outside of the oases consists mainly of plants with a tufty, dry, stiff habit of growth. The oases are the special home of the date-palm, of which there are about 4,000,000 in the Algerian oases alone. In company with this tree, without which life in the Sahara would be practically impossible, are grown apples, peaches, oranges, citrons, figs, grapes, pomegranates, &c. From December to March wheat, barley and other northern grain crops are successfully cultivated, and in the hotter season rice, dukhn, durra and other tropical products. Altogether the oasal flora has considerable variety; thirty-nine species are known from the Kufra group, forty-eight from the Aujila group.

Zoologically the Sahara is also partly Mediterranean, partly Tropical. Apart from the domestic animals (camels, asses, &c., and very noticeably a black breed of cattle in Adrar), the list of fifteen mammals comprises the jerboa, the fennek or fox, the jackal, the sand rat (Psammomys obesus), the hare, the wild ass and three species of antelope. In Borku, Air, &c., baboons, hyaenas and mountain sheep are not uncommon. Without counting migratory visitants, about eighty species of birds have been registered - the ostrich, the Certhilauda deserti or desert-lark (which often surprises the traveller with its song), Emberiza Saharae, three species of Dromolea, &c. Tortoises, lizards, chameleons, geckos, skinks, &c. of fifteen different species were collected by the single Rohlfs expedition of 1873-1874; the serpents comprise the horned viper, Psammophis sibilans, Coelopeltis lacertina, the python and several other species. The edible frog also occurs. Cyprinodon dispar, a fish not unlike Cyprinodon calaritanus, is found in all the brackish waters of north Sahara and swarms in the lake of the Siwa oasis.

The chief centres of population in the Sahara are, firstly, the oases, which occupy positions where the underground water makes its way to the surface or is readily reached by Centres boring; and, secondly, certain mountainous districts of popula- tion. where the atmospheric moisture is condensed, and a moderate rainfall is the result. Except in the south of Algeria, where cultivation has been extended by means of artesian wells, the condition of the Sahara oases is far from prosperous. Prior to the French occupation, a feeling of insecurity had been engendered by the marauding habits of the nomad tribes; cultivation had become more restricted; and the decline of the caravan trade had brought ruin to certain centres, such as Murzuk. The most important are the oases of the Tuat region, especially Insalah; those of Ghat and Ghadames on the route from Tripoli to Zinder; and of Kufra, in eastern Sahara (see Tuat and Tripoli). The various confederations of the Tuareg, in the central Sahara, are grouped round hilly districts. The most important are the Awellimiden, on the left bank of the Middle Niger; and the Kel-Ui, grouped around the mountainous districts of Air or Asben; the two northern confederations, those of the Ahaggar and Asjer, being less powerful. Much information respecting the Awellimiden confederation was obtained during the voyage down the Niger, in 1896, of Lieutenant Hourst of the French Navy, who was much struck with its powerful organization under the chief Madidu. Northwest of Timbuktu in the district or " Kingdom " of Biru is the oasis and town of Walata, a Tuareg settlement. Other mountainous districts in which a certain amount of rain falls regul rly, and which contain a population above the average for the Sahara, are Tibesti and Borku, in the east centre, and Adrar in the west. Tibesti and Borku are peopled by Tibbus; the western Adrar by Moors (Berbers). The northern portions of the Sahara are inhabited by nomad Arabs.

Attempts have been made by many explorers and writers to trace in certain of the existing inhabitants the remnants of an aboriginal race of negro affinities, which inhabited the Ethnology. Sahara before the arrival of the Berbers and Arabs. Ethnology. E. F. Gautier, writing in 1908, maintained that the evidence available (for the central Sahara) rendered probable the hypothesis that at a period perhaps as recent as the Roman conquest of North Africa the Sahara was still neolithic and peopled by a race of agricultural negroes, who extended to the confines of Algeria. Negro influence is undoubtedly seen in various parts of the Sahara, but it may date from a much more recent period than has been supposed. For example, the connexion between many of the place-names in Fezzan and the language of Bornu is attributable to the northward extension of the influence of the Bornu-Kanem empire between the 11th and 14th centuries A.D. The allusions by classical writers to Ethiopians as inhabitants of the Sahara prove little, in view of the very vague and general meaning attached to the word. The physical characteristics, and especially the dark colour, of many of the Saharan populations is apparently a stronger argument, but even this is capable of another explanation. Caravans of negro slaves from time immemorial passed northwards along the main desert routes, and it is just in the oases on these routes that the dark element in the population is chiefly found. It may therefore be attributed to the intermarriage of the original lighter inhabitants of the oases with such slaves. The Tibbu or Tebu, once thought to be almost pure negroes, proved, when examined by Gustav Nacht.igal in Tibesti, where they are foun greatest purity, to be a superior race with well-formed features and figures, of a light or dark bronze rather than black. Their language is related to that of the Kanuri in Bornu, but it appears that the Kanuri have derived theirs from the Tibbu, not the Tibbu from the Kanuri. Physically, the Tibbu appear to resemble somewhat the Tuareg, and there is little doubt that. they are a Hamitic, not a negro, people.

The commerce of the Sahara is not inconsiderable. Among the more important trade routes are (1) from Morocco to Cairo by Insalah and Ghadames, which is followed by the Commerce. pilgrims of western Africa bound for i1ecca; this route has been largely superseded by the sea route from Tangier to Alexandria; (2) from Kuka (Lake Chad) to Murzuk and Tripoli; (3) from Kano and Zinder to Tripoli by Air and Ghat; (4) from Timbuktu to Insalah, Ghadames and Tripoli;() from Timbuktu to Insalah and thence to Algeria and Tunisia; (6) from Timbuktu to Morocco. The Senussi movement brought into prominence the desert routes between Wadai in the south and Jalo and Benghazi in the north, which partially superseded some of the older routes. Other causes tended to reduce the importance of the old routes. The long-established route from Darfur to the Kharga and Dakhila oases fell into disuse on the closing of the eastern Sudan by the Mandist troubles. The great route leading from Tripoli via Ghadames and Ghat, to Zinder, Kano, and other great centres of the Hausa States maintains its importance, but the opening of trade from the side of the Niger by the British in the early years of the 20th century affected its value. The route across the western Sahara to Timbuktu is less used than formerly owing to the establishment by the French of a route from Senegal via Nioro to the Upper Nigel. The old route, however, retains some importance on account of the salt trade from the Sahara, which centres at Timbuktu. Salt and date palms are the chief products of the Sahara. The principal sources of the salt supply are the rock-salt deposits of the Juf (especially Taudeni), the lakes of Kufra and the rock salt and brine of Bilma (q.v.).

The hope of an eventual commercial exploitation of the Sahara rests mainly on the possible existence of mineral wealth. To supply easy communication between Algeria and Nigeria the Trans- construction of a railway across the desert has found many advocates. Two principal routes have been Saharan suggested, the one taking an easterly line from Biskra Railway through Wargla to Air (Agades) and Zinder - generally, Schemes. the route followed by Foureau (see below); the other starting from the terminus of the most westerly railway already existing, and reaching Timbuktu via Igli and the Tuat oases. A third suggested route is one from Igli to the Senegal, still farther west.

Reference may also be made to the proposal, strenuously advocated between 1870 and 1885, to open up the region to the south of Algeria and Tunisia by the construction of an inland sea. The According to Colonel Francois Roudaire (1836-1885), the Flooding author of this scheme, deceptively styled the " flooding of the of the Sahara," it was possible to create an inland sea Sahara. with an average depth of 78 ft. and an area of 3100 sq. m., or about fourteen times the size of the Lake of Geneva. A French government commission decided that the excavation of the necessary canal would not be difficult, and that in spite of silting-up processes the canal when cut would at least last moo to 1500 years. Ferdinand de Lesseps, Roudaire's principal supporter, visited the district in 1883 and reported that the canal would cost five years' labour and 150,000,000 francs. The scheme (which fell into abeyance on the death of R-oudaire) was based on the following facts. The Gulf of Gabes is separated by a ridge 13 m. across and 150 ft. high from Shat-al Fejej, a depression which extends S.W. into the Shat Jerid, which in its turn is separated from the Shat Rharsa only by a still narrower ridge. Shat Garsa is succeeded westwards by a series of smaller depressions, and beyond them lies the Shat Melrir, whose N.W. end is not far from the town of Biskra.

Politically the Sahara belongs partly to Morocco (Tafilet, &c.), partly to the Turkish empire (Tripoli, Egypt, &c.), but principally Political to France. The French first acquired an interest in the. Sahara by their conquest of Algiers (1830-45). They Pivisions gradually extended their influence southward with the purpose of forming a junction with their possessions on the Senegal. The acquisition of Tunisia (1881) largely increased the hold of the French on the Sahara, and the work of French pioneers to the south of Algeria was recognized by the Anglo-French agreement of 1890, which assigned to France the whole central Sahara from Algeria to a line from Say on the Niger to Lake Chad. The southern limit of the territory was, however, not strictly defined until 1898, when a new agreement gave to France a rectangular block south of the line mentioned, including the important frontier town of Zinder. A further agreement in 1904 again modified the frontier in favour of France. To the north-east and east the boundary of the French sphere was extended, by an Anglo-French Declaration of March 1899, and defined as running south-east, from the intersection of the Tropic of Cancer with 16° E., until it meets the meridian of 24° E., following this south to the frontier of Darfur. French Sahara is thus connected with the French possessions in West Africa and with the Congo-Shari territories of France on the south-east. On the west, where Spain claimed the Sahara coast between Capes Blanco and Bojador, the inland frontier was defined by the Franco-Spanish agreement of 1900, whereby Spain was apportioned a Hinterland with an average depth of 240 m. from the sea-shore.

It is impossible to ascertain the extent of the knowledge of the Sahara possessed by the ancients. The Egyptians penetrated the Libyan and Nubian deserts at points, and Carthaginians Explora- and Phoenicians were acquainted with the northern tion. fringe of the desert in the west. European exploration dates from the beginning of the 19th century. In 1819 Captain G. F. Lyon and Joseph Ritchie penetrated from Tripoli to Murzuk, where Ritchie died. In 1822 came the great journey of WalterOudney,Hugh ClappertonandDixonDenham, from Tripoli to Lake Chad, and a year or two later Major A. G. Laing succeeded in reaching Timbuktu, also from Tripoli. In 1828 Rene Caillie crossed from Timbuktu to Morocco. Heinrich Barth in the course of his great journey (1849-1856), commenced from Tripoli under the leadership of James Richardson, traversed a considerable portion of the Sahara. Between 1859 and 1861 Henri Duveyrier explored parts of the Tuareg domain. Knowledge of the northern Sahara, from Morocco to Tripoli, was largely increased by the journeys of Gerhard Rohlfs, begun in 1861; Rohlfs subsequently crossing (1865) from Tripoli to Lake Chad by nearly the same route as that previously taken by Barth. In1873-1874Rohlfs visited the oases in the north of the Libyan desert and in 1878187 9 reached the oasis of Kufra. In1876-1877another German traveller, Erwin von Bary, made his way to Ghat and Air, but was assassinated. A French expedition under Colonel Paul Flatters after penetrating far south of Algeria was massacred (1881) by Tuareg. Farther west success was attained in 1880 by a German explorer, Dr Oskar Lenz, who, starting from Morocco made his way, partly by a new route, to Timbuktu. In 18 9 2 the Sahara was crossed from Lake Chad to Tripoli by the French Colonel Monteil.

It was not until 1899 that the central Sahara, from Algeria to Air, was traversed for the first time by Europeans. This was accomplished under the leadership of Fernand Foureau. This journey was undertaken in pursuance of the efforts of the French to obtain effective control of the Sahara. South of Algeria military posts had been gradually pushed into the desert, Golea being until 1900 the farthest point which acknowledged French rule. The great desideratum was the opening up of a route to the Niger countries which might in time divert the trade from Tripoli to Algeria, but all attempts long proved fruitless, owing to the opposition of the tribes inhabiting central Sahara. In 1886 Lieutenant Palat was murdered a little south of Gurara, and in 1880 the same fate befell Camille Douls in Tidikelt (Tuat) in his attempt to reach Timbuktu from the north. In 1890 Foureau - who in 1883 had undertaken a first journey of exploration south of Wargla - reached the Tademayt plateau in 28° N., fixing the position of 35 places, and in1892-1893came the first of his long series of expeditions undertaken with a view of penetrating the country of the Azjer Tuareg, the powerful confederacy which lay on the route to Air and Lake Chad, never traversed in its entirety by a European. All efforts to obtain a passage were unavailing until in1898-1899Foureau, accompanied by an escort of troops under Major Lamy, at last attained his object, finally reaching Zinder, the important trade centre on the borders of Nigeria, and midway between the river Niger and Lake Chad, on the 2nd of November 1899.

The important section of Foureau's route began at Ain El-Hajaj,' in about 262° N., immediately beyond which the frowning massif of Tindesset had to be crossed by a most difficult route among a chaos of rocks and ravines, the geological formation being principally sandstone. After descending the southern escarpment of the " Tasili," the expedition crossed the mountainous region named Anahef, composed of quartz and granite, through which the line of partition between the basins of the Mediterranean and Atlantic was found to run. Thence the route lay across the wide plain of quartz gravel, strewn with blocks of granite, known to the Tuareg as Tiniri, to the well of In-Azaua, beyond which a march of eleven days, with a water-supply at one point only, led to the first village of Air, where the Tuareg proved hostile. Agades, the capital of Air, was reached by a march through difficult mountains, with valleys which gradually opened into a wide plain. From Agades to Zinder the route lay, first, through the bare and arid district of Azauak; next, through the bush-covered Tagama, a district abounding in game; and, lastly, through the cultivated country of Damerghu. Zinder had only once before been reached by way of Air - by Barth's expedition in 1850. It was now occupied by a French force which had advanced from the Niger (see Senegal: Colony).

Foureau's achievement was quickly followed by increased political activity of the French in the Sahara south of Algeria, where, in addition to the work of other explorers, surveys had been carried by French officers (especially Captains Germain and Laperrine in 1898) as far as the important centre of Insalah, the position of which had, as a result, been shifted some 25 m. E. of its former position on the maps, being found to lie in 2° 16' E., 20° 17' 30"N. Early in 1900 G. B. M. Flamand, who had been entrusted with a scientific mission to the Tuat oases, came into collision with the natives, and Insalah was occupied by the military escort which accompanied him. This was quickly followed by the occupation of Tuat, and Igli (see TuAT).

Simultaneously with these events, an attempt was made to pave the way for the establishment of French influence in western Sahara by the expedition of Paul Blanchet to Adrar, which had not been visited since the middle of the 19th century. It returned in September 1900, only partially successful, Blanchet and his companions having been detained for some time as virtual prisoners on the borders of Adrar. The leader almost immediately succumbed to fever. In1903-1909the country N. of the lower Senegal, including Adrar, was brought under French control and organized as the territory of Mauretania.

The most marked progress was, however, effected in the central Sahara, where the French posts were gradually pushed farther south under a military organization, which resulted in the complete pacification of the Tuareg countries. Travel was thus made possible from one border of the desert to the other, and a number of successful expeditions gathered a rich harvest of results respecting the mapping, geology, and other features of this part of the Sahara. Some of the best work was done by Laperrine, Arnaud, Cortier and Nieger on the military side, and, on the civilian, by Villatte, Gautier and Chudeau. Apart from these French enterprises, Hanns Vischer, a Swiss in the service of British Nigeria, in 1906 travelled from Tripoli to Bornu through Murzuk and Bilma. In 1910 Capt. A. H. Haywood traversed the Sahara, being the first Englishman to cross the desert from Gao to Insalah.

AuTH0RrrIEs

Vatonne, Mission de Ghadames (1863); H. Duveyrier, Les Touaregs du Nord (1864); Ville, Explor. geologique du Mzab, &c. (1867); A. Pomel, Le Sahara (1872); F. G. Rohlfs, Quer durch Afrika (1874), Drei Monate im libyschen Wiiste (1875) and Kufra (1881); V. Largeau, Le Pays de Rirha-Ouargla (1879); G. Nachtigal, Sdheird and Silddn (3 vols., 1879-1889); G. Rolland, " Le Cretace du Sahara septentrional " (with geological map of the Central Sahara), in Bull. de la Soc. Geol. de France (1881); Roudaire.

Rapport sur la derniere exped. des Chotts (1881) (and other reports by the same author); Tchihatchef, " The Deserts of Africa and Asia," in British Association Reports (Southampton, 1882); Derrecagaix, " Explor. du Sahara: les deux missions du Lieut.-Colonel Flatters," in Bull. de la Soc. de Geogr. (1882); O. Lenz, Timbuktu. Reise durch Marokko, eec. (1884); and E. L. Reclus, Nouv. Geographie univ. xi. (1886); H. Schirmer, Le Sahara (Paris, 1893); P. Vuillot, L'Exploration du Sahara (Paris, 1895); P. L. Monteil, De SaintLouis a Tripoli (Paris, 1895); Fr. Foureau, D' Alger au Congo par le Tchad (Paris, 1902) and Documents scientifiques de la mission saharienne, fasc. i.-iii. (Paris, 1903-1905); Privat-Deschanel, " Peut-on reboiser le Sahara? " Rev. scientif. (1896); K. A. Zittel, Paldontologie der libyschen Wiiste (Cassel, 1893); G. Rolland, Chemin de fer transsaharien, geologie du Sahara algerien, et apercu geologique sur le Sahara de l'ocean atlantique a la mer rouge (Paris, Imp. Nat., 1891); J. Walther, Die Denudation in der Wiiste (Leipzig, 1900); M. Honore, Le Transsaharien et la penetration francaise en Afrique (Paris, 1901); E. Diirkop, Die wirtschaftsand handelsgeographischen Provinzen der Sahara (Wolfenbiittel, 1902); W. J. Harding King, A Search for the Masked Tawareks (London, 1903); A. Bernard and N. Lacroix, La Penetration saharienne (Algiers, 1906); C. Velan, " Etat actuel de nos connaissances sur la geographie et la geologie du Sahara d'apres les explorations les plus recentes," Revue de geogr. t. i. (1906-1907), PP. 447-5 1 7; J. Lahache, " Le Dessechement de l'Afrique frangaise est-il demontre?" Bul. Soc. Geogr. Marseille, 31 (1907), pp. 1 4918 5; E. Arnaud and M. Cortier, Mission Arnaud-Cortier: nos confins sahariens (Paris, 1908); E. F. Gautier and R. Chudeau, Missions au Sahara, t. i. " Sahara algerien," par E. F. Gautier (Paris, 1908), t. ii. " Sahara sudanais," par R. Chudeau (Paris, 1909); H. Vischer, Across the Sahara from Tripoli to Bornu (London, 1910); H. J. Ll. Beadnell, " Sand Dunes of the Libyan Desert," Geog. Jour. (April 1910); E. Fallot, " Le Commerce du Sahara," Ques. dip. et col. t. 15 (1903), pp. 209-225. (E. HE.; F. R. C.)


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Wiktionary

Up to date as of January 15, 2010

Definition from Wiktionary, a free dictionary

See also saħara

Contents

English

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Wikipedia

Etymology

From Arabic صحراء “desert” (Sahara Desert is thus a pleonasm.)

Pronunciation

Proper noun

Singular
Sahara

Plural
-

Sahara

  1. A desert in North Africa, the largest hot desert in the world.

Derived terms

Translations


Bosnian

Proper noun

Sahara f.

  1. Sahara

German

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German Wikipedia has an article on:
Sahara

Wikipedia de

Proper noun

Sahara f.

  1. Sahara (desert in Africa)

Italian

Proper noun

Wikipedia-logo.png
Italian Wikipedia has an article on:
Sahara

Wikipedia it

Sahara m.

  1. Sahara

Derived terms


Polish

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Polish Wikipedia has an article on:
Sahara

Wikipedia pl

Proper noun

Sahara f.

  1. Sahara (desert in Africa)

Declension

Singular only
Nominative Sahara
Genitive Sahary
Dative Saharze
Accusative Saharę
Instrumental Saharą
Locative Saharze
Vocative Saharo

Serbian

Proper noun

Sahara f.

  1. Sahara

See also


Simple English

This article is about the desert. The article about the country can be found at Western Sahara
File:Sahara satellite
A satellite image of the Sahara.
File:Sahara
Sand dunes in the Sahara desert

The Sahara [1] in North Africa, is the one of the largest deserts in the world. Antarctica is also a desert, and is larger.[2]

It is bounded by the Atlantic Ocean, the Atlas Mountains, the Mediterranean Sea, the Red Sea, and the Sahel region. Inside it are parts of many countries, including Morocco, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Niger, Chad, and The Sudan. Most parts are uninhabited, but some people manage to survive in places where there is water.[3]

The Sahara Desert is about 9,065,000 square kilometers in size. It has been both larger and smaller at different times. Ater the last ice age it became more fertile, then dried up again. It is the hottest place on the Earth, but not the driest. The driest is the Atacama Desert in South America. The Sahara has about the same size as the whole United States.

Contents

Environment

The highest mountain is 3415 m, and is the Emi Koussi in Chad. Some mountain peaks in the Sahara Desert have snow even in the summer.[4][5] The main mountain ranges is the Atlas Mountains in Algeria. The Sahara's lowest point lies in the Qattara Depression in Egypt, at about 130 metres below sea level. Sand sheets and dunes are about 25% of the Sahara. All the other parts are mountains, steppes with a lot of stones, and oasises.[4]

There are several rivers running through the Sahara. However, most of them come and go through the seasons, except for the Nile River and Niger River.[4]

Metallic minerals are very important to most Saharan countries. Algeria and Mauritania have several major deposits of iron ore. There are also bits of uranium, while Niger has the largest parts of them. A lot of phosphates are in Morocco and Western Sahara. Oil is mainly found in Algeria. The oil is very important to the economy of the entire country. While the mineral exploitation has led to economic growth in Sahara, this has rarely helped the indigenous population, as skilled workers have been brought from other countries.

Cities

Of the Sahara's around 4 million people, most live in Mauritania, Western Sahara, Algeria, Libya and Egypt. Dominant groups of people are Sahrawis, Tuareg and Negroids. The largest city is Nouakchott, Mauritania's capital. Other important cities are Tamanrasset in Algeria, and Sebha and Ghat in Libya. Only 200,000 km² of Sahara are fertile oases, where dates, corn, and fruits are grown. The few fertile regions today are fed by underground rivers and underground basins. Many of Sahara's oases rests in depressions (areas under sea level) allowing water to surface from underground reservoirs; artesian wells.

The soil in Sahara is low in organic matter. The soil in depressions is often saline. Animal life is limited to gazelles, antelopes, jackals, foxes, badgers and hyena. Other sorts of vegetation include scattered concentrations of grasses, shrubs and trees in the highlands, as well as in the oases and along river beds. Some plants are well adjusted to the climate, allowing them to germinate within 3 days of rain and sow their seeds within 2 weeks after that. Animal life of Sahara include gerbil, jerboa, cape hare and desert hedgehog, barbary sheep, oryx, gazelle, deer, wild ass, baboon, hyena, jackal, sand fox, weasel and mongoose. The bird life counts more than 300 species.

References

  1. Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrā´ al-kubra, "The Greatest Desert"
  2. The Arctic is not a land mass.
  3. "Sahara (desert, Africa) -- Britannica Online Encyclopedia". britannica.com. http://www.britannica.com/EBchecked/topic/516375/Sahara. Retrieved 4 May 2010. 
  4. 4.0 4.1 4.2 "Sahara - LookLex Encyclopaedia". looklex.com. http://looklex.com/e.o/sahara.htm. Retrieved 4 May 2010. 
  5. "Snow in the Sahara". Algeria.com. http://www.algeria.com/blog/snow-in-summer-algerias-hoggar-mountains. Retrieved 5 August 2010. 

Other websites

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krc:Сахара

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