Last-Modified:  05/20/06 14:51                                    

Sahara Desert Information And Facts

Some particularly good facts about the biggest desert in the world! The Sahara.

The Sahara Desert With Pictures; Facts on Desertification.

THE SAHARA FACTS  about the Sahara Desert. The Sahara Desert is a great desert area, North Africa, the West portion of the broad belt of parched land that extends from the Atlantic Ocean eastward past the Red Sea to Iraq. The entire desert, the largest in the world, is about 1600 km wide and about 5000 km long from East to West. 

The total domain of the Sahara Desert is more than 9,000,000 sq. km, more than 3,500,000 square miles. Of which some 200,000 square km. Some 80,000 square miles, consist of partially fertile oases.

The limits of the Sahara Desert are the Atlantic Ocean on the West, the Atlas Mountains. and the Mediterranean Sea in the North.  The Red Sea and Egypt on the East, and the Sudan and the valley of the Niger River. in the South. The boundaries, however, are not clearly defined, and have been shifting for a thousand years. The Sahara was once a fertile area; millet and other grains were cultivated there over 8000 years ago. As conditions progressively became drier, however, and desertification set in, farmers abandoned their land.

Geographically distinct is the West Sahara, which is sometimes called the Sahara Proper; the central Ahaggar Mountains and the Tibesti Massif, are plateau regions.

The Libyan Desert is in the East. The West Sahara Desert is an area of rock-strewn plains and sand deserts of varying elevation. The land is presently almost entirely without rainfall or surface water but possesses a number of underground rivers that flow fast from the Atlas and other mountains. Occasionally the waters of these rivers find their way seeping to the surface; in these naturally irrigated oases, plants grow freely. The soil of this region of the Sahara is highly fertile and, where irrigation is possible, produces excellent crops.

The central plateau region of the Sahara Desert runs for about 1600 km, about 1000 miles in a Northwest to Southeast direction. The plateau itself varies in height, from about 600 to 750 m (about 1900 to 2500 ft). Peaks in the several mountain ranges that rise from the plateau are from about 1800, to more than 3400 m (about 6000 to more than 11,200 ft) high. 

Notable peaks include Emi Koussi (3415 m/11,204 ft), in the Tibesti Massif, and Tahat (3003 m / 9852 ft), in the Ahaggar Range. Although rainfall is scant in the area, several of the central Saharan peaks are snow-capped during part of the year.

The Libyan Sahara Desert is considered the most arid part of the Sahara. Moisture is almost totally absent and few oases exist. The land is characterized by sandy wastes and large dunes of sand 122 m (400 ft) or more in height. 

The valley of the Nile River and the mountainous area of the Nubian Desert to the East of the Nile are geographically, part of the Sahara. However, the irrigation afforded by the Nile transforms the desert into fertile agricultural land throughout much of Egypt.

THE SAHARA FACTS

 The Sahara Desert as a whole is a tableland with an average elevation  from  about 400 to 500 meters (1300 to 1600 ft).  Only  comparatively small areas are elevated as little as 150 m (500 ft) above sea level. In Egypt and Algeria, limited areas, such as the Qattarah Depression, are below sea level. The climate is   uniformly dry; most areas average less than 130 mm (less than   5 in) of rain per year, and some get none at all for years at a   time. The temperature range is extreme, ranging between   freezing to more than 55° C (130° F) in the West and central  portions. 

Except in the oases the desert is almost devoid of vegetation, although some stunted, thorny shrubs grow in the West Sahara. Artificial oases have been created by drilling water wells more than 1000 m (more than 3000 ft) deep. The principal trees of the oases are the date palm and a form of acacia. Gazelle and antelope are found in many parts of the desert, as are jackal, fox, badger, and hyena. 

The Libyan Desert is virtually devoid of any form of animal or vegetable life. The North Sahara has assumed economic importance with the discovery of extensive petroleum deposits in Algeria and Libya.

Tuareg, are a tribal people of the Sahara. They speak a Berber language, Tamarshak, and have their own alphabet. In ancient times, the Tuareg controlled the Trans-Sahara caravan routes. Taxing the goods they helped to convey, and raiding neighboring tribes. In modern times, their raiding was subdued by the French who ruled Algeria. The political division of Saharan Africa since the 1960s has made it increasingly difficult for the Tuareg to maintain their pastoral traditions.

Tuareg society distinguishes among nobles, vassals, and serfs. Slave-stealing expeditions have been abolished, but the Black descendants of former slaves still perform the menial tasks. 

Social status is determined through matrilineal descent. Converted by the Arabs to Islam, the Tuareg have retained some of their older rites. Among the Tuareg, for example, men—not women—wear a head - dress with a veil.

Many Tuareg starved in droughts in the 1970s, and others have migrated to cities. Today more than 300,000 Tuareg live in Algeria, Tunisia, Mali, Libya, Burkina Faso, and Niger.

© Copyright Microsoft 2005

          CONTACT US

THE SAHARA FACTS   

Taken from comments by

Dr. David Whitehouse

BBC News Online Science Editor

7-11-99

Using a new computer simulation of the Earth's climate German scientists say that the Sahara underwent a brutal climate change about 4,000 years ago. Over the next three hundred years the climate altered severely.

Ten thousand years ago the Sahara, the largest desert in the world, was covered by grass and low shrubs. Also there are records of areas being Rainforests and Swamps. A complete contrast to what is there today. Apparently for some reason summer temperatures increased and rainfall almost ceased. The change devastated many ancient cultures and caused those that did survive to migrate elsewhere, from what was previously perhaps Elysian Fields.

.

According to the researchers another, less severe, change occurred between 6,000 and 5,000 years ago. Scientists at the Potsdam Institute for Climate Research say that the desertification of the Sahara was one of the most dramatic changes in climate over the past 11,000 years. However, as we speak the deserts of the world still grow daily.

 The loss of agricultural land to the desert may have been one of the reasons why early civilizations developed along the valleys of the Nile, the Tigris and the Euphrates. Nothing can live without water

Slight climate alterations caused by subtle changes in the Earth's orbit around the Sun were amplified by a climatic feedback mechanism. Some 9,000 years ago the tilt of the Earth's axis was 24.14 degrees, today it is 23.45 degrees. Today the Earth is closest to the Sun in January. Nine thousand years ago the closest to the Sun occurred at the end of July. Perhaps the combination of the summer and being closer was enough to tip some balance.

The changes in the tilt of the Earth occur gradually however the interplay of atmosphere, ocean and landmass can react to these changes in abrupt and severe ways. The climate model suggests that land use by man was not an important factor in the creation of the Sahara. 

.

MAPS OF AFRICA   

The Sahara was once like this, it can be again.

DEFORESTATION

Before the dawn of agriculture approximately 10,000 years ago, forests and open woodland covered about 15 billion acres (6. billion ha) of the globe. Over the centuries, however, about one-third of these natural forests has been destroyed. According to a 1982 study by FAO, about  27.9 million acres (11.3 million ha) of tropical forests are cut each year; this is an area about the size of the States of Ohio or Virginia. 

Between 1985 and 1990, an estimated 210 million acres (85 million ha) of tropical forests were cut or cleared. In India, Malaysia, and the Philippines, the best commercial forests are gone, and cutting is increasing in South America. If deforestation is not stopped soon, the world will lose most of its tropical forests in the next several decades. 

'Save The Earth', J. Porritt

Reasons for Deforestation

Several factors are responsible for deforestation in the Tropics: clearing for agriculture, fuel wood cutting, and harvesting of wood products. By far the most important of these is clearing for agriculture. In the Tropics, the age-old practice of shifting, sometimes called "slash-and-burn," agriculture has been used for centuries. In this primitive system, local people cut a small patch of forest to make way for subsistence farming. After a few years, soil fertility declines and people move on, usually to cut another patch of trees and begin another garden.

In the abandoned garden plot, the degraded soil at first supports only weeds and shrubby trees. Later, soil fertility and trees return, but that may take decades. As population pressure increases, the fallow (rest) period between cycles of gardening is shortened, agricultural yields decrease, and the forest region is further degraded to small trees, brush, or eroded savanna.

Conversion to sedentary agriculture is an even greater threat to tropical forests. Vast areas that once supported tropical forests are now permanently occupied by subsistence farmers and ranchers and by commercial farmers who produce sugar, cocoa, palm oil, and other products.

In many tropical countries there is a critical shortage of firewood. For millions of rural poor, survival depends on finding enough wood to cook the evening meal. Every year more of the forest is destroyed, and the distance from home to the forest increases. Not only do people suffer by having to spend much of their time in the search for wood, but the land suffers also. 

Damage is greatest in dry tropical forests where firewood cutting converts forests to savannas and grasslands.

The global demand for tropical hardwoods, an $10-billion-a-year industry, also contributes to forest loss. Tropical forests are usually selectively logged rather than clear-cut. Selective logging leaves the forest cover intact but usually reduces its commercial value because the biggest and best trees are removed. Selective logging also damages remaining trees and soil, increases the likelihood of fire, and degrades the habitat for wildlife species that require large, old trees-the ones usually cut. In addition, logging roads open up the forests to shifting cultivation and permanent settlement.

Endangered Wildlife

Forests are biological communities-complex associations of trees with other plants and animals that have evolved together over millions of years. Because of the worldwide loss of tropical forests, thousands of species of birds and animals are threatened with extinction. The list includes many unique and fascinating animals, among them the orangutan, mountain gorilla, manatee, jaguar, and Puerto Rican parrot. Although diverse and widely separated around the globe, these species have one important thing in common. They, along with many other endangered species, rely on tropical forests for all or part of their habitat. 

Orangutans (Pongo pygmaeus) are totally dependent on small and isolated patches of tropical forests remaining in Borneo and Sumatra, Indonesia. Orangutans spend most of their time in the forest canopy where they feed on leaves, figs and other fruit, bark, nuts, and insects. Large trees of the old-growth forests support woody vines that serve as aerial ladders, enabling the animals to move about, build their nests, and forage for food. When the old forests are cut, orangutans disappear.

The largest of all primates, the gorilla, is one of man's closest relatives in the animal kingdom. Too large and clumsy to move about in the forest canopy, the gorilla lives on the forest floor where it forages for a variety of plant materials. Loss of tropical forests in central and west Africa is a major reason for the decreasing numbers of mountain gorillas (Gorilla gorilla). Some habitat has been secured, but the future of this gentle giant is in grave danger as a result of habitat loss and poaching.

The Jaguar (Leo Onca), a resident of the South-western United States and Central and South America, is closely associated with forests. Its endangered status is the result of hunting and habitat loss. 

   Sahara Desert

The Sahara

Pronounced As: shâr [Arabic,=desert], world's largest desert, c.3,500,000 sq mi (9,065,000 sq km), N Africa; the western part of a great arid zone that continues into SW Asia. Extending more than 3,000 mi (4,830 km), from the Atlantic Ocean to the Red Sea, the Sahara is bounded on the N by the Atlas Mts., steppelands, and the Mediterranean Sea; it stretches south c.1,200 mi (1,930 km) to the Sahel, a steppe in W and central Africa that forms its southern border. The desert includes most of Western Sahara, Mauritania, Algeria, Niger, Libya, and Egypt; the southern portions of Morocco and Tunisia; and the northern portions of Senegal, Mali, Chad, and Sudan. The E Sahara is usually divided into three regions-the Libyan Desert, which extends west from the Nile valley through W Egypt and E Libya; the Arabian Desert, or Eastern Desert, which lies between the Nile valley and the Red Sea in Egypt; and the Nubian Desert, which is in NE Sudan.

Regions of sand dunes (erg) occupy only about 15% of the Sahara; "stone deserts, consisting of plateaus of denuded rock (hammada) or areas of coarse gravel (reg), cover about 70% of the region; mountains, oases, and transition zones account for the remainder. Sparse vegetation is found in most parts of the Sahara, with the exception of the sand dune regions. High mountain massifs rise in the central regions; they are the Ahagger (Hoggar) in S Algeria, which rises to more than 9,000 ft (2,740 m); the Tibesti Massif in N Chad, which rises to more than 11,000 ft (3,350 m); and the Aïr Mountains (Azbine) in N Niger, which rise to more than 6,000 ft (1,830 m). The mountains are deeply dissected and were in the past infamous for the shelter they provided to marauders preying on desert traffic. From west to east the four principal land routes across the desert are from Colomb-Bechar to Dakar; from Colomb-Bechar to Gao and Timbuktu by way of Reganne; from Touggourt to Agadez and Kano by way of In-Salah; and from Tripoli to Ghat.

7 September 1999

Tilt of Earth’s axis turned Sahara into a desert

The Sahara and Arabia were transformed abruptly from fertile land covered with shrubs and grasses into a parched desert in a "brutal" period of climatic change lasting 400 years, scientists have found.

For once, humans were not to blame: the cause was not farming or overgrazing, as is usually thought. Scientists reckon that the Sahara began to turn into a desert after the Earth underwent one of its periodic changes in orientation, starting 9,000 and finishing about 6,000 years ago. Its tilt lessened from 24.14 degrees off vertical to its present 23.45 degrees, while the time when the planet is closest to the Sun shifted gradually from July to January.

Nobody knows what triggered the changes, but geologists think they were probably caused by shifts of material deep inside the Earth's molten core. They altered the pattern of sunshine on the Earth, with profound effects on many weather systems. The discovery has implications today, as many climate researchers are worried that gradual changes in the Earth's temperature caused by global warming will have marked effects on ocean currents - particularly those that warm Britain.

Before the change, the northern hemisphere received more summer sunlight, which amplified summer monsoons. But once the change was over, the new conditions created a vicious feedback loop between vegetation and climate. As the African monsoon lessened, plants began dying. As they stopped retaining water and releasing it back into the atmosphere, the rains lessened further, until rivers and streams dried up. The Sahara Desert now covers 3.5 million square miles.

The discovery emerged from a new computerized climate model made by a team of scientists at the Potsdam Institute for Climate Change.

"Our simulations show how interactions between vegetation, atmosphere and ocean current can lead to relatively abrupt climate changes - a process that might influence climate in future, too," said Martin Claussen, the team's leader.

"It was very severe, ruining ancient civilizations and socio-economic systems," he added. In the Sahara, "we find an abrupt decrease in vegetation, from a green Sahara to a desert scrublands within a few hundred years".

The ancient civilizatio