Jinnvisible
02-20-2010, 03:23 PM
Sahara Desert.
Land Forms
The SaharaDesert has many different landforms. Parts have sand dunes. A sand dune is a mountain of sand. Some dunes can be as high as 600 feet. These dunes are found in huge areas of shifting sand called ergs. Regs are another type of landform found in the desert. regs are broad plains covered with sand and gravel. Regs make up most of the Sahara. Hammadas also make up a large part of the Sahara. These are areas of flat, raised land that are also known as plateaus. There are volcanic mountains in the Sahara in the country of Chad. Emi Koussi, a peak in the Tibesti Mountains is 11, 204 feet high and the highest point in the desert.
Ergs
http://i49.tinypic.com/2uz55ah.jpg
Dune © SaharaMet R. Pelisson
http://i48.tinypic.com/ei19np.jpg
Erg © SaharaMet R. Pelisson
Otherwise known as sand seas, ergs are the Saharan dunes of popular imagination. They cover about 20 percent of the Sahara and can stretch for hundreds of miles at heights of up to 1,000 feet. The Grand Erg Occidental and Oriental cover most of Algeria; the Selima Erg blankets more than 3,000 square miles in Libya; the Erg Cherch stretches for 600 miles across Mali and Algeria. Formed in depressions, ergs, such as the Grand Erg of Bilma in Nigeria, can also contain large quantities of salt from dried-up ancient lakes that fuel the Sahara's salt trade.
Regs
http://i46.tinypic.com/24oplr6.jpg
Regs Libya © SaharaMet R. Pelisson
These plains of sand and black, red or white gravel make up 70 percent of the Sahara. The Libyan reg stretches for 340,000 square miles; the Tanezrouft reg, to the west of the AhaggarMountains, stretches for 200,000 square miles. The remains of prehistoric seas and rivers, the regs are now nearly completely waterless. Plant life is sparse; animal life is mostly limited to rodents
Hamadas
http://i45.tinypic.com/30ag7id.jpg
Hamadas Sahara Algeria © SaharaMet R. Pelisson
The Sahara's elevated plateaus of rock and stone, known as hamadas, can soar over 11,000 feet. They include the Atlas Mountains in southern Morocco and western Algeria; Tassili N'Ajjer massif in southeastern Algeria (up to 7,800 ft.); TibestiMountains of southern Libya and northern Chad (up to 11,204 ft.); the AhaggarMountains (9,852 feet), product of a volcanic explosion in the center of the Sahara. The Sahara's highest point? The summit of MountKoussi in the TibestiMountains. (11,204 ft.)
Wadis
http://i50.tinypic.com/11b0kfs.jpg
Andries3 Flickr Wadis
Wadis are temporary water sources located primarily in the mountains and fed by rainfall. They are home to most of the Sahara's trees and large bushes.
Chotts
http://i48.tinypic.com/2q2kc54.jpg
Chott Tunisia (damiandude flkr)
http://i47.tinypic.com/e7xo9t.jpg
Chott Tunisia tamerza (damiandude flkr)
Chotts are depressions that fill with salt once moisture from the Sahara's winter rains evaporates in the spring and summer. Large chotts occur throughout the northern Sahara. Key scenes from "The English Patient" and "Star Wars" were filmed in a large chott in western Tunisia called wChott el Djerid.
Oasis
http://i48.tinypic.com/2yjvqtk.jpg
Sahara oasis (Ninja Steve flickr)
http://i45.tinypic.com/nly937.jpg
Sahara oasis Libya (Howard Gees flickr)
http://i48.tinypic.com/2nbf6mf.jpg
Sahara oasis Libya (Ninja Steve flickr)
oasis can vary in size from about 2.5 acres for a tiny village to larger farm lands. At its hub is water, often in the form of natural springs, artesian wells or entire irrigation systems. About 75 percent of the Sahara's population live in oases, which make up only a tiny 800 square miles of the desert's vast sea of sand and gravel. The date palm is most characteristic of the vegetation that flourishes there. Other typical food sources grown in Saharan oases include figs, peaches, citrus fruits, wheat and barley. The word "oasis" is believed to come from an ancient Egyptian word, "wah," meaning "fertile place in the desert."
By studying satellite photos, some scientists have come to believe that the Sahara regularly shrinks and grows. In the early 1980s, the Sahara's southern edge expanded into the Sahel, a dry band that separates the desert from the savanna. But by the mid-1980s this area was green and wet again. _
Many of Sahara's oases rests in depressions (areas under sea level) allowing water to surface from underground reservoirs; artesian wells.
As animals and humans travel desert trade routes, they stop at oases to stock up on water. Some oases are just wells in the desert; others support bustling towns. People almost always grow crops, bargain over goods and share news at oases.
As caravaneers plan their trips across the Sahara, they rely on the knowledge of oasis locations passed down through their families, as well as on their own experience. As Tuareg women move their herds of goats, sheep and donkeys from one of the Sahara's dry pastures to another, they make sure that they're never far from water.
The Sahara covers huge 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.
Several deeply dissected mountains and mountain ranges, many volcanic, rise from the desert, including the AïrMountains, AhaggarMountains, Saharan Atlas, TibestiMountains, 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 NileRiver, 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. ~
The fauna of the Sahara includes about 70 species of mammals, 300 species of birds, including 90 species of resident birds, and around 100 species of reptiles. Owing to extreme heat, most small desert creatures are nocturnal. The populations of these species were greatly reduced by over-hunting and many are now endangered species, like the ostrich, addax, some species of gazelles and the cheetah. Most of the African large mammals that were reported to have been present in the desert until the second half of the 19th century have now become extinct. Some of these animals can be seen in FezzanPark, and also in Tripoli's zoo. ~
Sources; PBS.org, Tooter4 kids, Wikipedia, Calacademy, Temehu Libian Tourism.
http://www.saharamet.com/index.html
All images cleared for copyright.
Land Forms
The SaharaDesert has many different landforms. Parts have sand dunes. A sand dune is a mountain of sand. Some dunes can be as high as 600 feet. These dunes are found in huge areas of shifting sand called ergs. Regs are another type of landform found in the desert. regs are broad plains covered with sand and gravel. Regs make up most of the Sahara. Hammadas also make up a large part of the Sahara. These are areas of flat, raised land that are also known as plateaus. There are volcanic mountains in the Sahara in the country of Chad. Emi Koussi, a peak in the Tibesti Mountains is 11, 204 feet high and the highest point in the desert.
Ergs
http://i49.tinypic.com/2uz55ah.jpg
Dune © SaharaMet R. Pelisson
http://i48.tinypic.com/ei19np.jpg
Erg © SaharaMet R. Pelisson
Otherwise known as sand seas, ergs are the Saharan dunes of popular imagination. They cover about 20 percent of the Sahara and can stretch for hundreds of miles at heights of up to 1,000 feet. The Grand Erg Occidental and Oriental cover most of Algeria; the Selima Erg blankets more than 3,000 square miles in Libya; the Erg Cherch stretches for 600 miles across Mali and Algeria. Formed in depressions, ergs, such as the Grand Erg of Bilma in Nigeria, can also contain large quantities of salt from dried-up ancient lakes that fuel the Sahara's salt trade.
Regs
http://i46.tinypic.com/24oplr6.jpg
Regs Libya © SaharaMet R. Pelisson
These plains of sand and black, red or white gravel make up 70 percent of the Sahara. The Libyan reg stretches for 340,000 square miles; the Tanezrouft reg, to the west of the AhaggarMountains, stretches for 200,000 square miles. The remains of prehistoric seas and rivers, the regs are now nearly completely waterless. Plant life is sparse; animal life is mostly limited to rodents
Hamadas
http://i45.tinypic.com/30ag7id.jpg
Hamadas Sahara Algeria © SaharaMet R. Pelisson
The Sahara's elevated plateaus of rock and stone, known as hamadas, can soar over 11,000 feet. They include the Atlas Mountains in southern Morocco and western Algeria; Tassili N'Ajjer massif in southeastern Algeria (up to 7,800 ft.); TibestiMountains of southern Libya and northern Chad (up to 11,204 ft.); the AhaggarMountains (9,852 feet), product of a volcanic explosion in the center of the Sahara. The Sahara's highest point? The summit of MountKoussi in the TibestiMountains. (11,204 ft.)
Wadis
http://i50.tinypic.com/11b0kfs.jpg
Andries3 Flickr Wadis
Wadis are temporary water sources located primarily in the mountains and fed by rainfall. They are home to most of the Sahara's trees and large bushes.
Chotts
http://i48.tinypic.com/2q2kc54.jpg
Chott Tunisia (damiandude flkr)
http://i47.tinypic.com/e7xo9t.jpg
Chott Tunisia tamerza (damiandude flkr)
Chotts are depressions that fill with salt once moisture from the Sahara's winter rains evaporates in the spring and summer. Large chotts occur throughout the northern Sahara. Key scenes from "The English Patient" and "Star Wars" were filmed in a large chott in western Tunisia called wChott el Djerid.
Oasis
http://i48.tinypic.com/2yjvqtk.jpg
Sahara oasis (Ninja Steve flickr)
http://i45.tinypic.com/nly937.jpg
Sahara oasis Libya (Howard Gees flickr)
http://i48.tinypic.com/2nbf6mf.jpg
Sahara oasis Libya (Ninja Steve flickr)
oasis can vary in size from about 2.5 acres for a tiny village to larger farm lands. At its hub is water, often in the form of natural springs, artesian wells or entire irrigation systems. About 75 percent of the Sahara's population live in oases, which make up only a tiny 800 square miles of the desert's vast sea of sand and gravel. The date palm is most characteristic of the vegetation that flourishes there. Other typical food sources grown in Saharan oases include figs, peaches, citrus fruits, wheat and barley. The word "oasis" is believed to come from an ancient Egyptian word, "wah," meaning "fertile place in the desert."
By studying satellite photos, some scientists have come to believe that the Sahara regularly shrinks and grows. In the early 1980s, the Sahara's southern edge expanded into the Sahel, a dry band that separates the desert from the savanna. But by the mid-1980s this area was green and wet again. _
Many of Sahara's oases rests in depressions (areas under sea level) allowing water to surface from underground reservoirs; artesian wells.
As animals and humans travel desert trade routes, they stop at oases to stock up on water. Some oases are just wells in the desert; others support bustling towns. People almost always grow crops, bargain over goods and share news at oases.
As caravaneers plan their trips across the Sahara, they rely on the knowledge of oasis locations passed down through their families, as well as on their own experience. As Tuareg women move their herds of goats, sheep and donkeys from one of the Sahara's dry pastures to another, they make sure that they're never far from water.
The Sahara covers huge 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.
Several deeply dissected mountains and mountain ranges, many volcanic, rise from the desert, including the AïrMountains, AhaggarMountains, Saharan Atlas, TibestiMountains, 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 NileRiver, 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. ~
The fauna of the Sahara includes about 70 species of mammals, 300 species of birds, including 90 species of resident birds, and around 100 species of reptiles. Owing to extreme heat, most small desert creatures are nocturnal. The populations of these species were greatly reduced by over-hunting and many are now endangered species, like the ostrich, addax, some species of gazelles and the cheetah. Most of the African large mammals that were reported to have been present in the desert until the second half of the 19th century have now become extinct. Some of these animals can be seen in FezzanPark, and also in Tripoli's zoo. ~
Sources; PBS.org, Tooter4 kids, Wikipedia, Calacademy, Temehu Libian Tourism.
http://www.saharamet.com/index.html
All images cleared for copyright.