Sahara

Sahara Desert (الصحراء الكبرى)
Desert
A satellite image of the Sahara by NASA World Wind
Countries Algeria, Chad, Egypt, Eritrea, Ethiopia, Libya, Mali, Mauritania, Morocco, Niger, Somalia, Sudan, Tunisia, Western Sahara
Range Tibesti Mountains
Landmark Pyramids of Giza
River Nile River
Highest point Emi Koussi 11,204 ft (3,415 m)
 - coordinates
Lowest point Qattara Depression -436 ft (−132.9 m)
 - coordinates
Length 4,800 km (2,983 mi), E/W
Width 1,800 km (1,118 mi), N/S
Area 9,400,000 km² (3,629,360 sq mi)
Biome Desert
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 hot desert. At over 9,400,000 square kilometres (3,600,000 sq mi), it covers most of Northern Africa, making it almost as large as Europe or the United States. The only larger desert in the world is Antarctica, classified as such due to very low precipitation rates. The Sahara 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.

Some of the sand dunes can reach 180 metres (590 ft) in height.[1] The name comes from the Arabic word for desert: (صَحراء), "ṣaḥrā´" (صحراء; [sˤɑħrɑːʔ]).[2][3]

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 Air 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[4] 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 [5] 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 (Aeolian processes) 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).[6] 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[7] and geographer Robert Capot-Rey,[8][9] 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.[10]

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.[8][9] 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).[10]

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.[11] During the last glacial period, the Sahara was even bigger than it is today, extending south beyond its current boundaries.[12] 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.[13]

Once the ice sheets were gone, northern Sahara dried out. In the southern Sahara though, 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.[14]

By around 3400 BC, the monsoon retreated south to approximately where it is today,[15] leading to the gradual desertification of the Sahara.[16] The Sahara is now as dry as it was about 13,000 years ago.[11] 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.[17] 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.[18] 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.[19] Deforestation has also caused the Sahara to advance south in recent years, 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.[20]

Snow and ice

On February 18, 1979, snowfall in several places in southern Algeria, including a half-hour snowstorm that stopped traffic in Ghardaïa, was reported in newspapers around the world as '[snow in the Sahara] for the first time in living memory'.[21] The snow was gone within hours.[22]

Several Saharan mountain ranges, however, receive snow on a more regular basis. Although relative humidity is low in the arid environment, the absolute humidity is sufficiently high to condense when driven up a mountain range. In winter, temperatures drop low enough on the 3,003 meters (9,852 ft) Tahat summit, highest peak of the Ahaggar Mountains, to cause snow every third year; the inaccessible Tibesti Mountains are said to receive snow on peaks over 2,500 meters (8,202 ft) every seventh year.[23][24]

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:

Flora and fauna

Shadows of camels with travelers on dunes in Tunisia

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

The central Sahara is estimated to include only five hundred species of plants, which is extremely low considering the huge extent of the area. Plants such as acacia trees, palms, succulents, spiny shrubs, and grasses have adapted to the arid conditions, either by reducing water loss or storing water. Plant leaves may dry out totally and then recover. Human activities are more likely to affect the habitat in areas of permanent water (oases) or where water comes close to the surface. Here, the local pressure on natural resources can be intense. The remaining populations of large mammals have been greatly reduced by hunting for food and recreation. In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization.

History

Photo of the Sahara from 1908

Berbers

Berbers are one of the oldest known inhabitants of the Sahara Desert. They are the people that occupied (and still occupy) more than two thirds of the Sahara's total surface. The Garamantes Berbers built a prosperous empire in the heart of the desert. 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.

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.[37] 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.[38] 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.[37] 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.[39] Megaliths found at Nabta Playa are overt examples of probably the world's first known Archaeoastronomy devices, predating Stonehenge by some 1000 years.[40] 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.[41]

Phoenicians

The people 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 people of Ancient Libya, who were the ancestors of people 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.[11] 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.[42]

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.

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 utilize 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.

See also

  • List of deserts by area
  • Arid Lands Information Network           
  • Azaouad
  • Sahara Conservation Fund
  • Saharan explorers
  • Green Sahara

References

Notes

  1. ↑ Arthur N. Strahler and Alan H. Strahler. (1987) Modern Physical Geography–Third Edition. New York: John Wiley & Sons. Page 347
  2. ↑ "Sahara." Online Etymology Dictionary. Douglas Harper, Historian. Retrieved June 25, 2007.
  3. ↑ "English-Arabic online dictionary". Online.ectaco.co.uk. 2006-12-28. http://online.ectaco.co.uk/main.jsp?do=e-services-dictionaries-word_translate1&status=translate&lang1=23&lang2=ar&source_id=2119140. Retrieved 2010-06-12. 
  4. ↑ Discover Magazine, 2006-Oct.
  5. ↑ National Geographic News, 2006-06-17.
  6. ↑ "Sahara desert" WWF Scientific Report [1]. Retrieved December 30, 2007.
  7. ↑ Wickens, Gerald E. (1998) Ecophysiology of Economic Plants in Arid and Semi-Arid Lands. Springer, Berlin. ISBN 978-3-540-52171-6
  8. ↑ 8.0 8.1 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. 
  9. ↑ 9.0 9.1 Bisson, J. (2003). Mythes et réalités d'un désert convoité: le Sahara. L'Harmattan. (French)
  10. ↑ 10.0 10.1 Walton, K. (2007). The Arid Zones. Aldine. 
  11. ↑ 11.0 11.1 11.2 Kevin White and David J. Mattingly (2006). Ancient Lakes of the Sahara. 94. American Scientist. pp. 58–65 
  12. ↑ Christopher Ehret. The Civilizations of Africa. University Press of Virginia, 2002.
  13. ↑ Fezzan Project — Palaeoclimate and environment. Retrieved March 15, 2006.
  14. ↑ "Geophysical Research Letters" Simulation of an abrupt change in Saharan vegetation in the mid-Holocene - July 15th, 1999
  15. ↑ Sahara's Abrupt Desertification Started by Changes in Earth's Orbit, Accelerated by Atmospheric and Vegetation Feedbacks.
  16. ↑ 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. 
  17. ↑ Oxfam Cool Planet - the Sahara - access February 10, 2008
  18. ↑ Tiempo Climate Newswatch: Climate Change and the Sahara
  19. ↑ "Expansion and contraction of the Sahara Desert between 1980 and 1990| Science 253: 299-301". Ciesin.columbia.edu. 1991-07-19. http://www.ciesin.columbia.edu/docs/005-319/005-319.html. Retrieved 2010-06-12. 
  20. ↑ "Sahara Desert Greening Due to Climate Change?". News.nationalgeographic.com. http://news.nationalgeographic.com/news/2009/07/090731-green-sahara.html. Retrieved 2010-06-12. 
  21. ↑ "Think It's Cold Here? It Snowed On Sahara!". New York Times (New York City, NY: The New York Times Company): pp. D4. 19 February 1979. http://select.nytimes.com/gst/abstract.html?res=F4081EFB3A5D12728DDDA00994DA405B898BF1D3. Retrieved 17 June 2010. 
  22. ↑ "Snow Falls In The Sahara". The Spokesman-Review: Eastern Washington Edition (Spokane, WA: Cowles Publishing Company): pp. 1. 19 February 1979. http://news.google.com/newspapers?id=UsoRAAAAIBAJ&sjid=9O0DAAAAIBAJ&dq=snow%20sahara&pg=2960%2C2123284. 
  23. ↑ Messerli, B. (1973). "Problems of Vertical and Horizontal Arrangement in the High Mountains of the Extreme Arid Zone". Arctic and Alpine Research (Boulder, CO: University of Colorado) 5 (3): 139–147. http://www.jstor.org/stable/1550163. Retrieved 17 June 2010. 
  24. ↑ Kendrew, Wilfrid George (1922). The Climates of the Continents. Oxford: The Clarendon press. pp. 27. ISBN 9781406781724. http://books.google.com/?id=pyDpdkVOInMC&pg=PA27&lpg=PA27&dq=ahaggar+snowcapped&q. 
  25. ↑ "Atlantic coastal desert" WWF Scientific Report [2]. Retrieved December 29, 2007.
  26. ↑ "North Saharan steppe and woodlands" WWF Scientific Report [3]. Retrieved December 29, 2007.
  27. ↑ "Sahara desert" WWF Scientific Report [4]. Retrieved December 29, 2007.
  28. ↑ "South Saharan steppe and woodlands" WWF Scientific Report [5]. Retrieved December 29, 2007.
  29. ↑ "West Saharan montane xeric woodlands" WWF Scientific Report [6]. Retrieved December 29, 2007.
  30. ↑ "Tibesti-Jebel Uweinat montane xeric woodlands" WWF Scientific Report [7]. Retrieved December 29, 2007.
  31. ↑ "Saharan halophytics" WWF Scientific Report [8]. Retrieved December 29, 2007.
  32. ↑ Pianka, E.R.; King, D.R. and King, R.A. 2004. Varanoid Lizards of the World. Indiana University Press.
  33. ↑ McNutt et al. (2008). Lycaon pictus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 06 May 2008.
  34. ↑ Borrell, Brendan (2009-08-19). "Endangered in South Africa: Those Doggone Conservationists". Slate. http://www.slate.com/id/2225607/entry/2225663/. 
  35. ↑ "" Rare cheetah captured on camera"". BBC News. 2009-02-24. http://news.bbc.co.uk/2/hi/science/nature/7905986.stm. Retrieved 2010-06-12. 
  36. ↑ http://www.iucnredlist.org/apps/redlist/details/221/0/full The IUCN Red List of Threatened Species: Acinonyx jubatus ssp. hecki
  37. ↑ 37.0 37.1 Predynastic] (5,500–3,100 BC), Tour Egypt].
  38. ↑ Fayum, Qarunian (Fayum B, about 6000–5000 BC?), Digital Egypt.
  39. ↑ "History of Nubia". Anth.ucsb.edu. http://www.anth.ucsb.edu/faculty/stsmith/research/nubia_history.html. Retrieved 2010-06-12. 
  40. ↑ PlanetQuest: The History of Astronomy - Retrieved on 2007-08-29
  41. ↑ Late Neolithic megalithic structures at Nabta Playa - by Fred Wendorf (1998)
  42. ↑ Keys, David. 2004. Kingdom of the Sands. Archaeology. Volume 57 Number 2, March/April 2004. Abstract. Retrieved March 13, 2006.

Bibliography

External links