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117-453: The Sahara ( / s ə ˈ h ɑːr ə / , / s ə ˈ h ær ə / ) is a desert spanning across North Africa . With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic . The name "Sahara" is derived from Arabic : صَحَارَى , romanized :  ṣaḥārā /sˤaħaːraː/ ,

234-879: A broken plural form of ṣaḥrā' ( صَحْرَاء /sˤaħraːʔ/ ), meaning "desert". The desert covers much of North Africa , excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb , and the Nile Valley in Egypt and the Sudan . It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where

351-405: A derivative of Arabic . However, these areas are not generally considered part of North Africa, but rather Southern Europe, due to their proximity to mainland Europe and their European-based cultures and religion. The Maghreb or western North Africa on the whole is believed to have been inhabited by Berbers and their ancestors since at least 10,000 B.C., while the eastern part of North Africa or

468-401: A bed of flowers. The three are assumed to have died within 24 hours of each other, but as their skeletons hold no apparent trauma (they did not die violently) and they have been buried so elaborately – unlikely if they had died of a plague – the cause of their deaths is a mystery. North Africa North Africa (sometimes Northern Africa ) is a region encompassing the northern portion of

585-426: A consequence, the weather tends to be sunny, dry and stable with a minimal chance of rainfall. Subsiding, diverging, dry air masses associated with subtropical high-pressure systems are extremely unfavorable for the development of convectional showers. The subtropical ridge is the predominant factor that explains the hot desert climate ( Köppen climate classification BWh ) of this vast region. The descending airflow

702-403: A continental scale rather than being confined to a particular corner of Africa. In September 2019, scientists reported the computerized determination, based on 260 CT scans , of a virtual skull shape of the last common human ancestor to modern humans / H. sapiens , representative of the earliest modern humans, and suggested that modern humans arose between 260,000 and 350,000 years ago through

819-596: A date of up to 1.8 million BCE. Recent finds in Jebel Irhoud in Morocco have been found to contain some of the oldest Homo sapiens remains; This suggests that, rather than arising only in East Africa around 200,000 years ago, early Homo sapiens may already have been present across the length of Africa 100,000 years earlier. According to study author Jean-Jacques Hublin, "The idea is that early Homo sapiens dispersed around

936-594: A distinctive Maghrebi ancestry formed from a mixture of Near Eastern and African ancestry, which is still found as a part of the genome of modern Northwest Africans. Later during the Neolithic , from around 7,500 years ago onwards, there was a migration into Northwest Africa of European Neolithic Farmers from the Iberian Peninsula (who had originated in Anatolia several thousand years prior), as well as pastoralists from

1053-635: A large amount of their genetic, ethnic, cultural and linguistic identity and influence with the Middle East / West Asia , a process that began with the Neolithic Revolution c.  10,000 BC and pre Dynastic Egypt. The countries of North Africa are also a major part of the Arab world . The Islamic and Arab influence in North Africa has remained dominant ever since, with the region being major part of

1170-579: A merging of populations in East and Southern Africa . The cave paintings found at Tassili n'Ajjer , north of Tamanrasset, Algeria, and at other locations depict vibrant and vivid scenes of everyday life in central North Africa during the Neolithic Subpluvial period (about 8000 to 4000 BCE). Some parts of North Africa began to participate in the Neolithic revolution in the 6th millennium BCE, just before

1287-505: A second official language after Arabic. French also serves as an administrative language in Algeria, Morocco and Tunisia. The most spoken dialects are Maghrebi Arabic , a form of ancient Arabic dating back from the 8th century AD, and Egyptian Arabic . The largest and most numerous ethnic group in North Africa are the Arabs . In Algeria and Morocco, Berbers are the second largest ethnic group after

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1404-605: 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. According to climatic criteria, the southern limit of the Sahara corresponds to the 150 mm (5.9 in) isohyet of annual precipitation (this

1521-538: A surface feature of Earth, with near-current technology. The Sahara is mainly rocky hamada (stone plateaus); ergs (sand seas – large areas covered with sand dunes ) form only a minor part, contrary to common misconception , but many of the sand dunes are over 180 metres (590 ft) high. Wind or rare rainfall shape the desert features: sand dunes, dune fields, sand seas, stone plateaus, gravel plains ( reg ), dry valleys ( wadi ), dry lakes ( oued ), and salt flats ( shatt or chott ). Unusual landforms include

1638-677: Is "no or scanty evidence" of human presence in the Egyptian Nile Valley during these periods, which may be due to problems in site preservation. Several scholars have argued that the African origins of the Egyptian civilisation derived from pastoral communities which emerged in both the Egyptian and Sudanese regions of the Nile Valley in the fifth millennium BCE. When Egypt entered the Bronze Age,

1755-614: Is a long-term average, since precipitation varies annually). Important cities located in the Sahara include Nouakchott , the capital of Mauritania; Tamanrasset , Ouargla , Béchar , Hassi Messaoud , Ghardaïa , and El Oued in Algeria; Timbuktu in Mali; Agadez in Niger; Ghat in Libya; and Faya-Largeau in Chad. The Sahara is the world's largest hot desert . It is located in the horse latitudes under

1872-422: Is a north African gazelle that can also go for a long time without water. Other notable gazelles include the rhim gazelle and dama gazelle . The Saharan cheetah ( northwest African cheetah ) lives in Algeria, Togo , Niger, Mali, Benin , and Burkina Faso . There remain fewer than 250 mature cheetahs, which are very cautious, fleeing any human presence. The cheetah avoids the sun from April to October, seeking

1989-545: Is a prehistoric industry, or domain, that existed between 10,000 and 8,000 years ago in the Sahara, during the Neolithic Subpluvial . Human remains from this culture were found in 2000 at a site known as Gobero , located in Niger in the Ténéré Desert . The site is known as the largest and earliest grave of Stone Age people in the Sahara. The Kiffians were skilled hunters . Bones of many large savannah animals that were discovered in

2106-589: Is a significant minority of Coptic Christians . The Copts are the largest Christian denomination in the Middle East and North Africa . The Maghreb formerly had a significant Jewish population, almost all of whom emigrated to France or Israel when the North African nations gained independence. Prior to the modern establishment of Israel, there were about 500,000 Jews in Northern Africa, including both Sephardi Jews (refugees from Spain, France and Portugal from

2223-460: Is associated with high rates of wind-blown mineral dust, and these dust levels are found as expected in marine cores from the north tropical Atlantic. But around 12,500 BCE the amount of dust in the cores in the Bølling / Allerød phase suddenly plummets and shows a period of much wetter conditions in the Sahara, indicating a Dansgaard-Oeschger (DO) event (a sudden warming followed by a slower cooling of

2340-403: Is estimated to include 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, by growing lower to avoid water loss by strong winds, by storing water in their thick stems to use it in dry periods, by having long roots that travel horizontally to reach

2457-528: Is now with the extent of the tropical forests being greatly reduced, and the lower temperatures reduced the strength of the Hadley Cell . This is a climate cell which causes rising tropical air of the Inter-Tropical Convergence Zone (ITCZ) to bring rain to the tropics, while dry descending air, at about 20 degrees north , flows back to the equator and brings desert conditions to this region. It

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2574-622: Is one of the vast plateaux of Africa , formed of ancient base rock covered by the sediment of shallow seas and alluvial deposits . Among the rivers of the Atlas, the Saharan Atlas feeds wadis . Among these are the Chelif and Touil wadis, riverbeds that contains water only during wet periods, respectively draining the Amour and Ouled-Naïl ranges of the Saharan Atlas. The Saharan Atlas Mountains mark

2691-580: Is particularly fertile and most of Egypt lives close to the river. Elsewhere, irrigation is essential to improve crop yields on the desert margins. The inhabitants of North Africa are roughly divided in a manner corresponding to the principal geographic regions of North Africa: the Maghreb , the Nile valley, and the Sahel . The countries making up North Africa all have Modern Standard Arabic as their official language. Additionally, Algeria and Morocco recognize Berber as

2808-643: Is the strongest and the most effective over the eastern part of the Great Desert, in the Libyan Desert: this is the sunniest, driest and the most nearly "rainless" place on the planet, rivaling the Atacama Desert , lying in Chile and Peru . The rainfall inhibition and the dissipation of cloud cover are most accentuated over the eastern section of the Sahara rather than the western. The prevailing air mass lying above

2925-423: Is unique in that due to the extreme high temperatures of their habitat, and the threat of predators, the ants are active outside their nest for only about ten minutes per day. Dromedary camels and goats are the domesticated animals most commonly found in the Sahara. Because of its qualities of endurance and speed, the dromedary is the favourite animal used by nomads . Human activities are more likely to affect

3042-421: Is very unreliable and erratic in the Sahara as it may vary considerably year by year. In full contrast to the negligible annual rainfall amounts, the annual rates of potential evaporation are extraordinarily high, roughly ranging from 2,500 millimetres (100 in) per year to more than 6,000 millimetres (240 in) per year in the whole desert. Nowhere else on Earth has air been found as dry and evaporative as in

3159-533: The Adrar of Mauritania and a value of 75 °C (167 °F) has been measured in Borkou , northern Chad. Due to lack of cloud cover and very low humidity, the desert usually has high diurnal temperature variations between days and nights. However, it is a myth that the nights are especially cold after extremely hot days in the Sahara. On average, nighttime temperatures tend to be 13–20 °C (23–36 °F) cooler than in

3276-573: The African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of the Western Sahara in the west, to Egypt and Sudan's Red Sea coast in the east. The most common definition for the region's boundaries includes Algeria , Egypt , Libya , Morocco , Tunisia , and Western Sahara , the territory disputed between Morocco and

3393-520: The Afroasiatic language family . The Tuareg Berber languages are notably more conservative than those of the coastal cities. Over the years, Berbers have been influenced by contact with other cultures: Egyptians , Greeks , Punic people , Romans , Vandals , Arabs , Europeans , and Africans . The cultures of the Maghreb and the Sahara therefore combines Arab, indigenous Berber and African elements. In

3510-479: The Algerian Desert called Bou Bernous , at an elevation of 378 metres (1,240 ft) above sea level, and only Death Valley, California rivals it. Other hot spots in Algeria such as Adrar , Timimoun , In Salah , Ouallene , Aoulef , Reggane with an elevation between 200 and 400 metres (660 and 1,310 ft) above sea level get slightly lower summer average highs, around 46 °C (114.8 °F) during

3627-593: The Egyptians . In the seventh and eighth centuries, Arabs from the Arabian Peninsula swept across the region during the early Muslim conquests . The Arab migrations to the Maghreb began immediately after, which started a long process of Islamization and Arabization that has defined the cultural landscape of North Africa ever since. Many but not all Berbers and Egyptians gradually merged into Arab - Islamic culture . The countries and people of North Africa share

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3744-963: The Ksour Range in the west, the Amour Range in its central and the Ouled-Naïl Range at its eastern end. It also includes the Aurès ( Belezma ), the Hodna Mountains , the Nememcha Range and the Zab Mountains. The Tell Atlas and the Saharan Atlas merge in the east to join together into the Tébessa Range and the Medjerda Mountains. Bordered in the north by the Hautes Plaines , the Saharan Atlas

3861-740: The Late Pleistocene Iberomaurusians , early Holocene Capsians , and mid-Holocene Mechta groups, whereas the Tenerian crania are more like those of Mediterranean groups. Graves show that the Tenerians observed spiritual traditions, as they were buried with artifacts such as jewelry made of hippo tusks and clay pots. The most interesting find is a triple burial, dated to 5300 years ago, of an adult female and two children, estimated through their teeth as being five and eight years old, hugging each other. Pollen residue indicates they were buried on

3978-480: The Levant , both of whom also significantly contributed to the ancestry of modern Northwest Africans. The proto-Berber tribes evolved from these prehistoric communities during the late Bronze - and early Iron ages. The majority of the people of the Maghreb and the Sahara regions speak varieties of Arabic and almost exclusively follow Islam. The Arabic and Berber languages are distantly related, both being members of

4095-714: The Libyan Desert . For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle caused by the precession of Earth's axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon . The Sahara covers large parts of Algeria , Chad , Egypt , Libya , Mali , Mauritania , Niger , Western Sahara and Sudan , and parts of southern Morocco and Tunisia . It covers 9 million square kilometres (3,500,000 sq mi), 31% of

4212-580: The Middle Ages much of the area was loosely under the control of the Ottoman Empire . The Barbary pirates operated from the largely independent Barbary states located on the coast of North Africa. The Spanish Empire conquered several coastal cities between the 16th and 18th centuries. After the 19th century, the imperial and colonial presence of France , the United Kingdom , Spain and Italy left

4329-643: The Muslim world . North Africa is associated with the Middle East in the realm of geopolitics to form the Middle East-North Africa region. North Africa has three main geographic features: the Sahara desert in the south, the Atlas Mountains in the west, and the Nile River and delta in the east. The Atlas Mountains extend across much of northern Algeria , Morocco , and Tunisia . These mountains are part of

4446-533: The Nile Valley has mainly been home to the Egyptians and Nubians . Ancient Egyptians record extensive contact in their Western desert with people that appear to have been Berber or proto-Berber. As the Tassili n'Ajjer and other rock art findings in the Sahara have shown, the Sahara also hosted various populations before its rapid desertification in 3500 B.C and even today continues to host small populations of nomadic trans-Saharan peoples . Laboratory examination of

4563-723: The Richat Structure in Mauritania. Several deeply dissected mountains, 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. The central Sahara is hyperarid , with sparse vegetation. The northern and southern reaches of

4680-510: The Strait of Gibraltar , whereupon they overcame the fickle Roman defense. The loss of North Africa is considered a pinnacle point in the fall of the Western Roman Empire as Africa had previously been an important grain province that maintained Roman prosperity despite the barbarian incursions, and the wealth required to create new armies. The issue of regaining North Africa became paramount to

4797-717: The Uan Muhuggiag child mummy and Tin Hanakaten child, suggested that the Central Saharan peoples from the Epipaleolithic , Mesolithic , and Pastoral periods possessed dark skin complexions. The archaeological evidence from the Holocene period has shown that Nilo-Saharan speaking groups had populated the central and southern Sahara before the influx of Berber and Arabic speakers, around 1500 years ago, who now largely populate

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4914-415: The fold mountain system that also runs through much of Southern Europe . They recede to the south and east, becoming a steppe landscape before meeting the Sahara desert, which covers more than 75 percent of the region. The tallest peaks are in the High Atlas range in south-central Morocco, which has many snow-capped peaks. South of the Atlas Mountains is the dry and barren expanse of the Sahara desert,

5031-428: The partially recognized Sahrawi Arab Democratic Republic . The United Nations ' definition includes all these countries as well as the Sudan . The African Union defines the region similarly, only differing from the UN in excluding the Sudan. The Sahel , south of the Sahara Desert , can be considered as the southern boundary of North Africa. North Africa includes the Spanish cities of Ceuta and Melilla , and

5148-426: The plazas de soberanía . It can also be considered to include Malta , as well as other Italian, Portuguese, and Spanish regions such as Lampedusa and Lampione , Madeira , and the Canary Islands , which are all closer or as close to the African continent than Europe. Northwest Africa has been inhabited by Berbers since the beginning of recorded history , while the eastern part of North Africa has been home to

5265-446: The subtropical ridge , a significant belt of semi-permanent subtropical warm-core high pressure where the air from the upper troposphere usually descends, warming and drying the lower troposphere and preventing cloud formation. The permanent absence of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent. As

5382-400: The African continent. If all areas with a mean annual precipitation of less than 250 mm (9.8 in) were included, the Sahara would be 11 million square kilometres (4,200,000 sq mi). It is one of three distinct physiographic provinces of the African massive physiographic division . The Sahara is so large and bright that, in theory, it could be detected from other stars as

5499-415: The African humid period. At its largest extent, sometime before 5000 BCE, Lake Mega-Chad was the largest of four Saharan paleolakes, and is estimated to have covered an area of 350,000 km. The Sahara pump theory describes this cycle. During periods of a wet or " Green Sahara ", the Sahara becomes a savanna grassland and various flora and fauna become more common. Following inter-pluvial arid periods,

5616-461: The Arab majority. Arabs constitute 70% to 80% of the population of Algeria, 92% 97% of Libya, 67% to 70% of Morocco and 98% of Tunisia's population. The Berbers comprise 20% of Algeria, 10% of Libya, 35% of Morocco and 1% of Tunisia's population. The region is predominantly Muslim with a Jewish minority in Morocco and Tunisia , and significant Christian minority—the Copts —in Egypt , Algeria , Morocco, Libya, and Tunisia. In 2001,

5733-411: The Great Desert the hottest large region in the world, and the hottest place on Earth during summer in some spots. The average high temperature exceeds 38 to 40 °C (100.4 to 104.0 °F) during the hottest month nearly everywhere in the desert except at very high altitudes. The world's highest officially recorded average daily high temperature was 47 °C (116.6 °F) in a remote desert town in

5850-401: The Intertropical Convergence Zone from the south and the annual average rainfall ranges from 100 millimetres (4 in) to 250 millimetres (10 in). For example, Timbuktu, Mali and Agadez , Niger are found in this zone. The vast central hyper-arid core of the desert is virtually never affected by northerly or southerly atmospheric disturbances and permanently remains under the influence of

5967-412: The Kiffian culture do not exist after 8,000 years ago, as the Sahara went through a dry period for the next thousand years. After this time, the Tenerian culture colonized the area. Gobero was discovered in 2000 during an archaeological expedition led by Paul Sereno , which sought dinosaur remains. Two distinct prehistoric cultures were discovered at the site: the early Holocene Kiffian culture, and

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6084-514: The Maghreb remained focused on small-scale subsistence in small, highly mobile groups. Some Phoenician and Greek colonies were established along the Mediterranean coast during the 7th century BCE. The most notable nations of antiquity in western North Africa are Carthage , Numidia and Mauretania . The Phoenicians colonized much of North Africa including Carthage and parts of present-day Morocco (including Chellah , Essaouira and Volubilis ). The Carthaginians were of Phoenician origin, with

6201-520: The Renaissance era) as well as indigenous Mizrahi Jews . Today, less than 3,000 remain in the region, almost all in Morocco and Tunisia, and are mostly part of a French-speaking urban elite. (See Jewish exodus from Arab and Muslim countries .) Due to the recent African origin of modern humans , the history of Prehistoric North Africa is important to the understanding of pre-hominid and early modern human history in Africa. Some researchers have postulated that North Africa rather than East Africa served as

6318-450: The Roman myth of their origin being that Dido , a Phoenician princess, was granted land by a local ruler based on how much land she could cover with a piece of cowhide. She ingeniously devised a method to extend the cowhide to a high proportion, thus gaining a large territory. She was also rejected by the Trojan prince Aeneas according to Virgil , thus creating a historical enmity between Carthage and Rome , as Aeneas would eventually lay

6435-449: The Romans, resulting in the Carthaginian North African territories becoming the Roman province of Africa in 146 B.C. This led to tension and eventually conflict between Numidia and Rome. The Numidian wars are notable for launching the careers of both Gaius Marius , and Sulla , and stretching the constitutional burden of the Roman republic as Marius required a professional army, something previously contrary to Roman values, to overcome

6552-439: The Sahara (birds in particular) such as African silverbill and black-faced firefinch , among others. There are also small desert crocodiles in Mauritania and the Ennedi Plateau of Chad. The deathstalker scorpion 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 Saharan silver ant

6669-408: The Sahara area then reverts to desert conditions and the flora and fauna are forced to retreat northwards to the Atlas Mountains , southwards into West Africa , or eastwards into the Nile Valley . This separates populations of some of the species in areas with different climates , forcing them to adapt , possibly giving rise to allopatric speciation . It is also proposed that humans accelerated

6786-420: The Sahara in the modern era. After migrating to North Africa in the 1st millennium BC, Semitic Phoenician settlers from the Levant established over 300 coastal colonies throughout the region and built a powerful empire that controlled most of the region from the 8th century BC until the middle of the 2nd century BC. Several waves of Arab migrations to the Maghreb began in the 7th century, including

6903-399: The Sahara is strongly influenced by the North Atlantic Oscillation (NAO), with warmer winter temperatures during negative NAO events and cooler winters with more frosts when the NAO is positive. This is because the weaker clockwise flow around the eastern side of the subtropical anticyclone during negative NAO winters, although too dry to produce more than negligible precipitation, does reduce

7020-441: The Sahara is the continental tropical (cT) air mass, which is hot and dry. Hot, dry air masses primarily form over the North-African desert from the heating of the vast continental land area, and it affects the whole desert during most of the year. Because of this extreme heating process, a thermal low is usually noticed near the surface, and is the strongest and the most developed during the summertime. The Sahara High represents

7137-406: The Sahara region. However, at least two instances of snowfall have been recorded in Sahara, in February 1979 and December 2016, both in the town of Ain Sefra . One theory for the formation of the Sahara is that the monsoon in Northern Africa was weakened because of glaciation during the Quaternary period, starting two or three million years ago. Another theory is that the monsoon was weakened when

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7254-444: The Sahara, the distinction between sedentary oasis inhabitants and nomadic Bedouin Arabs and Tuaregs is particularly marked. Egyptians over the centuries have shifted their language from Egyptian (in its late form, varieties of Coptic ) to modern Egyptian Arabic while retaining a sense of national identity that has historically set them apart from other people in the region. Most Egyptians are Sunni Muslim , although there

7371-546: 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. Shifts in Earth's axis increased temperatures and decreased precipitation, which caused an abrupt beginning of North Africa desertification about 5,400 years ago. The Kiffian culture

7488-459: The Western Empire, but was frustrated by Vandal victories. The focus of Roman energy had to be on the emerging threat of the Huns . In 468 AD, the Romans made one last serious attempt to invade North Africa but were repelled. This perhaps marks the point of terminal decline for the Western Roman Empire . The last Roman emperor was deposed in 476 by the Heruli general Odoacer . Trade routes between Europe and North Africa remained intact until

7605-410: The amount of rainfall received – the Northern (Mediterranean), Central and Southern Zones. There are two transitional zones – the Mediterranean-Sahara transition and the Sahel transition zone. The Saharan flora comprises around 2800 species of vascular plants . Approximately a quarter of these are endemic . About half of these species are common to the flora of the Arabian deserts. The central Sahara

7722-420: The ancient Tethys Sea dried up during the Tortonian period around 7 million years ago. The climate of the Sahara has undergone enormous variations between wet and dry over the last few hundred thousand years, believed to be caused by long-term changes in the North African climate cycle that alters the path of the North African Monsoon – usually southward. The cycle is caused by a 41,000-year cycle in which

7839-421: The atmospheric circulation itself, the desert is made even drier by its geographical configuration and location. Indeed, the extreme aridity of the Sahara is not only explained by the subtropical high pressure: the Atlas Mountains of Algeria, Morocco and Tunisia also help to enhance the aridity of the northern part of the desert. These major mountain ranges act as a barrier, causing a strong rain shadow effect on

7956-448: The climate). The moister Saharan conditions had begun about 12,500 BCE, with the extension of the ITCZ northward in the northern hemisphere summer, bringing moist wet conditions and a savanna climate to the Sahara, which (apart from a short dry spell associated with the Younger Dryas ) peaked during the Holocene thermal maximum climatic phase at 4000 BCE when mid-latitude temperatures seem to have been between 2 and 3 degrees warmer than in

8073-401: The coming of Islam. Some Berbers were members of the Early African Church (but evolved their own Donatist doctrine ), some were Berber Jews , and some adhered to traditional Berber religion . African pope Victor I served during the reign of Roman emperor Septimius Severus . Furthermore, during the rule of the Romans, Byzantines, Vandals, Ottomans and Carthaginians the Kabyle people were

8190-438: The continent and elements of human modernity appeared in different places, and so different parts of Africa contributed to the emergence of what we call modern humans today." Early humans may have comprised a large, interbreeding population dispersed across Africa whose spread was facilitated by a wetter climate that created a "green Sahara", around 330,000 to 300,000 years ago. The rise of modern humans may thus have taken place on

8307-473: The daytime. The smallest variations are found along the coastal regions due to high humidity and are often even lower than a 10 °C (18 °F) difference, while the largest variations are found in inland desert areas where the humidity is the lowest, mainly in the southern Sahara. Still, it is true that winter nights can be cold, as it can drop to the freezing point and even below, especially in high-elevation areas. The frequency of subfreezing winter nights in

8424-467: The desert experiences around three to five months when the average high strictly exceeds 40 °C (104 °F); while in the southern central part of the desert, there are up to six or seven months when the average high temperature strictly exceeds 40 °C (104 °F). Some examples of this are Bilma , Niger and Faya-Largeau, Chad. The annual average daily temperature exceeds 20 °C (68 °F) everywhere and can approach 30 °C (86 °F) in

8541-563: The desert, along with the highlands, have areas of sparse grassland and desert shrub , with trees and taller shrubs in wadis , where moisture collects. In the central, hyperarid region, there are many subdivisions of the great desert: Tanezrouft , the Ténéré , the Libyan Desert , the Eastern Desert , the Nubian Desert and others. These extremely arid areas often receive no rain for years. To

8658-769: The desert: Tripolitania in the northwest and Cyrenaica in the northeast. Most of Egypt is also desert, with the exception of the Nile River and the irrigated land along its banks. The Nile Valley forms a narrow fertile thread that runs along the length of the country. Sheltered valleys in the Atlas Mountains, the Nile Valley and Delta , and the Mediterranean coast are the main sources of fertile farming land. A wide variety of valuable crops including cereals, rice and cotton, and woods such as cedar and cork , are grown. Typical Mediterranean crops, such as olives, figs, dates and citrus fruits, also thrive in these areas. The Nile Valley

8775-525: The drying-out period from 6000 to 2500 BCE by pastoralists overgrazing available grassland. The growth of speleothems (which requires rainwater) was detected in Hol-Zakh, Ashalim , Even-Sid, Ma'ale-ha-Meyshar, Ktora Cracks, Nagev Tzavoa Cave, and elsewhere, and has allowed tracking of prehistoric rainfall. The Red Sea coastal route was extremely arid before 140 and after 115 kya (thousands of years ago). Slightly wetter conditions appear at 90–87 kya, but it still

8892-645: The eastern continental extension of the Azores High , centered over the North Atlantic Ocean . The subsidence of the Sahara High nearly reaches the ground during the coolest part of the year, while it is confined to the upper troposphere during the hottest periods. The effects of local surface low pressure are extremely limited because upper-level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by

9009-597: The edge of the desert thousands of years ago, since the end of the last glacial period . In the Central Sahara, engraved and painted rock art were created perhaps as early as 10,000 years ago, spanning the Bubaline Period , Kel Essuf Period , Round Head Period , Pastoral Period , Caballine Period , and Cameline Period . The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles survive, with half found in

9126-562: The eleventh century, a reformist movement made up of members that called themselves the Almoravid dynasty expanded south into Sub-Saharan Africa . North Africa's populous and flourishing civilization collapsed after exhausting its resources in internal fighting and suffering devastation from the invasion of the Banu Sulaym and Banu Hilal . Ibn Khaldun noted that the lands ravaged by Banu Hilal invaders had become completely arid desert. After

9243-695: The entirety of the region under one form of European occupation. In World War II from 1940 to 1943 the area was the setting for the North African Campaign . During the 1950s and 1960s all of the North African states gained independence. There remains a dispute over Western Sahara between Morocco and the Algerian -backed Polisario Front . The wider protest movement known as the Arab Spring began with revolutions in Tunisia and Egypt which ultimately led to

9360-529: The exit point for the modern humans who first trekked out of the continent in the Out of Africa migration. The earliest inhabitants of central North Africa have left behind significant remains: early remnants of hominid occupation in North Africa, for example, were found in Ain el Hanech, near Saïda ( c.  200,000 BCE ); in fact, more recent investigations have found signs of Oldowan technology there, and indicate

9477-475: The flow of dry, cold air from higher latitudes of Eurasia into the Sahara significantly. The average annual rainfall ranges from very low in the northern and southern fringes of the desert to nearly non-existent over the central and the eastern part. The thin northern fringe of the desert receives more winter cloudiness and rainfall due to the arrival of low pressure systems over the Mediterranean Sea along

9594-518: The foundations for Rome. Ancient Carthage was a commercial power and had a strong navy, but relied on mercenaries for land soldiers. The Carthaginians developed an empire in the Iberian Peninsula , Malta , Sardinia , Corsica and northwest Sicily , the latter being the cause of First Punic War with the Romans . Over a hundred years and more, all Carthaginian territory was eventually conquered by

9711-698: 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 . Researchers from Hacettepe University have reported that Saharan soil may have bio-available iron and also some essential macro and micro nutrient elements suitable for use as fertilizer for growing wheat. People lived on

9828-404: The highest recorded worldwide. The sky is usually clear above the desert, and the sunshine duration is extremely high everywhere in the Sahara. Most of the desert has more than 3,600 hours of bright sunshine per year (over 82% of daylight hours), and a wide area in the eastern part has over 4,000 hours of bright sunshine per year (over 91% of daylight hours). The highest values are very close to

9945-543: The hottest months of the year. Salah, well known in Algeria for its extreme heat, has average high temperatures of 43.8 °C (110.8 °F), 46.4 °C (115.5 °F), 45.5 °C (113.9 °F) and 41.9 °C (107.4 °F) in June, July, August and September respectively. There are even hotter spots in the Sahara, but they are located in extremely remote areas, especially in the Azalai , lying in northern Mali. The major part of

10062-483: The hottest regions year-round. However, most of the desert has a value in excess of 25 °C (77 °F). Sand and ground temperatures are even more extreme. During daytime, the sand temperature is extremely high: it can easily reach 80 °C (176 °F) or more. A sand temperature of 83.5 °C (182.3 °F) has been recorded in Port Sudan . Ground temperatures of 72 °C (161.6 °F) have been recorded in

10179-518: The landscape gradually changes from desert to coastal plains. To the south it is bounded by the Sahel , a belt of semi-arid tropical savanna around the Niger River valley and the Sudan region of sub-Saharan Africa . The Sahara can be divided into several regions, including the western Sahara, the central Ahaggar Mountains , the Tibesti Mountains , the Aïr Mountains , the Ténéré desert, and

10296-496: The largest sand desert in the world. In places the desert is cut by irregular watercourses called wadis —streams that flow only after rainfall but are usually dry. The Sahara's major landforms include ergs , large seas of sand that sometimes form into huge dunes ; the hammada , a level rocky plateau without soil or sand; and the reg , a desert pavement . The Sahara covers the southern part of Algeria, Morocco and Tunisia, and most of Libya. Only two regions of Libya are outside

10413-404: The last glacial period , the Sahara was much larger than it is today, extending south beyond its current boundaries. The end of the glacial period brought more rain to the Sahara, from about 8000 BCE to 6000 BCE, perhaps because of low pressure areas over the collapsing ice sheets to the north. Once the ice sheets were gone, the northern Sahara dried out. In the southern Sahara, the drying trend

10530-455: The late nineteenth century, The hypothesis was later formally proposed and tested by the meteorologist John Kutzbach in 1981. Kutzbach's ideas about the impacts of insolation on global monsoonal patterns have become widely accepted today as the underlying driver of long-term monsoonal cycles. Kutzbach never formally named his hypothesis and as such it is referred to here as the " Orbital Monsoon Hypothesis " as suggested by Ruddiman in 2001. During

10647-518: The leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates. The primary source of rain in the Sahara is the Intertropical Convergence Zone , a continuous belt of low-pressure systems near the equator which bring the brief, short and irregular rainy season to the Sahel and southern Sahara. Rainfall in this giant desert has to overcome

10764-419: The maximum area of water and to find any surface moisture, and by having small thick leaves or needles to prevent water loss by evapotranspiration . Plant leaves may dry out totally and then recover. Several species of fox live in the Sahara including: the fennec fox , pale fox and Rüppell's fox . The addax , a large white antelope , can go nearly a year in the desert without drinking. The dorcas gazelle

10881-437: The middle Holocene Tenerian culture . The post-Kiffian desiccation lasted until around 4600 BCE, when the earliest artefacts associated with the Tenerians have been dated to. Some 200 skeletons have been discovered at Gobero. The Tenerians were considerably shorter in height and less robust than the earlier Kiffians. Craniometric analysis also indicates that they were osteologically distinct. The Kiffian skulls are akin to those of

10998-572: The migration of the Banu Hilal and the Banu Sulaym westward into the Maghreb in the eleventh century, which introduced Arab culture and language to the countryside. Historians mark their movement as a critical moment in the Arabization of North Africa. As Arab nomads spread, the territories of the local Berber tribes were moved and shrank. The Zenata were pushed to the west and the Kabyles were pushed to

11115-562: The north, the Sahara skirts the Mediterranean Sea in Egypt and portions of Libya, but in Cyrenaica and the Maghreb , the Sahara borders the Mediterranean forest, woodland, and scrub eco-regions of northern Africa, all of which have a Mediterranean climate characterized by hot summers and cool and rainy winters. According to the botanical criteria of Frank White and geographer Robert Capot-Rey,

11232-482: The north. The Berbers took refuge in the mountains whereas the plains were Arabized. This heavily shifted the demographics of the Maghreb. The trans-Saharan slave trade resulted in increased levels of sub-Saharan African ancestry in North Africa. The Haratin are commonly perceived as an endogamous group of former slaves or descendants of slaves. DNA studies of Iberomaurusian peoples at Taforalt , Morocco dating to around 15,000 years ago have found them to have

11349-421: The northern limit of the Sahara corresponds to the northern limit of date palm cultivation and the southern limit of the range of esparto , 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. To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with

11466-482: The number of Christians in North Africa was estimated at 9 million, the majority of whom live in Egypt, with the remainder live in Maghreb countries. The inhabitants of the Spanish Canary Islands are of mixed Spanish and North African Berber ancestry, and the people of Malta are of primarily Southern Italian/Sicilian, as well as, to a lesser extent, North African and Middle Eastern ancestry and speak

11583-532: The only or one of the few in North Africa who remained independent. The Kabyle people were incredibly resistible so much so that even during the Arab conquest of North Africa they still had control and possession over their mountains. The early Muslim conquests included North Africa by 640. By 700, most of North Africa had come under Muslim rule. Indigenous Berbers subsequently started to form their own polities in response in places such as Fez and Sijilmasa . In

11700-454: The opposite is true, with decreased annual precipitation and less vegetation resulting in a phase of the Sahara climate cycle known as the "desert Sahara". The idea that changes in insolation (solar heating) caused by long-term changes in Earth's orbit are a controlling factor for the long-term variations in the strength of monsoon patterns across the globe was first suggested by Rudolf Spitaler in

11817-461: The overthrow of their governments, as well as civil war in Libya. Large protests also occurred in Algeria and Morocco to a lesser extent. Many hundreds died in the uprisings. Further information in the sections of Architecture of Africa : Further information in the sections of History of science and technology in Africa : Saharan Atlas The Saharan Atlas includes a series of subranges:

11934-419: The physical and atmospheric barriers that normally prevent the production of precipitation. The harsh climate of the Sahara is characterized by: extremely low, unreliable, highly erratic rainfall; extremely high sunshine duration values; high temperatures year-round; negligible rates of relative humidity ; a significant diurnal temperature variation ; and extremely high levels of potential evaporation which are

12051-401: The polar front, although very attenuated by the rain shadow effects of the mountains and the annual average rainfall ranges from 100 millimetres (4 in) to 250 millimetres (10 in). For example, Biskra , Algeria, and Ouarzazate , Morocco, are found in this zone. The southern fringe of the desert along the border with the Sahel receives summer cloudiness and rainfall due to the arrival of

12168-412: The rapid desertification of the Sahara around 3500 B.C. largely due to a tilt in the Earth's orbit. It was during this period that domesticated plants and animals were introduced in the region, spreading from the north and east to the southwest. There has been an inferred connection between areas of rapid drying and the introduction of livestock in which the natural (orbital) aridification was amplified by

12285-517: The recent past. Analysis of Nile River deposited sediments in the delta also shows this period had a higher proportion of sediments coming from the Blue Nile , suggesting higher rainfall also in the Ethiopian Highlands . This was caused principally by a stronger monsoonal circulation throughout the sub-tropical regions, affecting India, Arabia and the Sahara. Lake Victoria only recently became

12402-584: The same area suggest that they lived on the shores of a lake that was present during the Holocene Wet Phase, a period when the Sahara was verdant and wet. The Kiffian people were tall, standing over six feet in height. Craniometric analysis indicates that this early Holocene population was closely related to the Late Pleistocene Iberomaurusians and early Holocene Capsians of the Maghreb, as well as mid-Holocene Mechta groups. Traces of

12519-458: The scale of the Nile floods between 2700 and 2100 BCE. The Sahara comprises several distinct ecoregions . With their variations in temperature, rainfall, elevation, and soil, these regions harbor distinct communities of plants and animals. The flora of the Sahara is highly diversified based on the bio-geographical characteristics of this vast desert. Floristically , the Sahara has three zones based on

12636-517: The shelter of shrubs such as balanites and acacias. They are unusually pale. The other cheetah subspecies ( northeast African cheetah ) lives in Chad, Sudan and the eastern region of Niger. However, it is currently extinct in the wild in Egypt and Libya. There are approximately 2000 mature individuals left in the wild. Other animals include the monitor lizards , hyrax , sand vipers , and small populations of African wild dog , in perhaps only 14 countries and red-necked ostrich . Other animals exist in

12753-619: The source of the White Nile and dried out almost completely around 15 kya. The sudden subsequent movement of the ITCZ southwards with a Heinrich event (a sudden cooling followed by a slower warming), linked to changes with the El Niño-Southern Oscillation cycle, led to a rapid drying out of the Saharan and Arabian regions, which quickly became desert. This is linked to a marked decline in

12870-599: The spread of shrubs and open land due to grazing. Nevertheless, changes in northern Africa's ecology after 3500 BCE provided the backdrop for the formation of dynastic civilizations and the construction of monumental architecture such as the Pyramids of Giza . Archaeological evidence has attested that population settlements occurred in Nubia as early as the Late Pleistocene era and from the 5th millennium BC onwards, whereas there

12987-561: The strongest anticyclonic weather regime, and the annual average rainfall can drop to less than 1 millimetre (0.04 in). In fact, most of the Sahara receives less than 20 millimetres (0.8 in). Of the 9,000,000 square kilometres (3,500,000 sq mi) of desert land in the Sahara, an area of about 2,800,000 square kilometres (1,100,000 sq mi) (about 31% of the total area) receives an annual average rainfall amount of 10 millimetres (0.4 in) or less, while some 1,500,000 square kilometres (580,000 sq mi) (about 17% of

13104-560: The talented military leader Jugurtha . Kingdom of Mauretania remained independent until being annexed to the Roman Empire by Emperor Claudius in 42 AD. North Africa remained a part of the Roman Empire, producing notable citizens, including Augustine of Hippo , until incompetent leadership from Roman commanders in the early fifth century allowed the Germanic peoples , the Vandals , to cross

13221-546: The theoretical maximum value. A value of 4300 hours (98%) of the time would be recorded in Upper Egypt ( Aswan , Luxor ) and in the Nubian Desert ( Wadi Halfa ). The annual average direct solar irradiation is around 2,800 kWh/(m year) in the Great Desert. The Sahara has a huge potential for solar energy production. The high position of the Sun, the extremely low relative humidity, and the lack of vegetation and rainfall make

13338-408: The tilt of the earth changes between 22° and 24.5°. At present, it is in a dry period, but it is expected that the Sahara will become green again in 15,000 years. When the North African monsoon is at its strongest, annual precipitation and subsequent vegetation in the Sahara region increase, resulting in conditions commonly referred to as the " green Sahara ". For a relatively weak North African monsoon,

13455-476: The total area) receives an average of 5 millimetres (0.2 in) or less. The annual average rainfall is virtually zero over a wide area of some 1,000,000 square kilometres (390,000 sq mi) in the eastern Sahara comprising deserts of: Libya, Egypt and Sudan ( Tazirbu , Kufra , Dakhla , Kharga , Farafra , Siwa , Asyut , Sohag , Luxor, Aswan, Abu Simbel , Wadi Halfa) where the long-term mean approximates 0.5 millimetres (0.02 in) per year. Rainfall

13572-400: Was initially counteracted by the monsoon , which brought rain further north than it does today. By around 4200 BCE, however, the monsoon retreated south to approximately where it is today, leading to the gradual desertification of the Sahara. The Sahara is now as dry as it was about 13,000 years ago. Lake Chad is the remnant of a former inland sea, paleolake Mega-Chad, which existed during

13689-487: Was just one tenth the rainfall around 125 kya. In the southern Negev Desert speleothems did not grow between 185 and 140 kya ( MIS 6), 110–90 (MIS 5.4–5.2), nor after 85 kya nor during most of the interglacial period (MIS 5.1), the glacial period and Holocene . This suggests that the southern Negev was arid-to-hyper-arid in these periods. During the Last Glacial Maximum (LGM) the Sahara was more extensive than it

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