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Erg Chech
The Erg Chech (), is a large erg in southwestern Algeria and northern Mali. Geography It is an almost uninhabited part of the greater Sahara Desert, an inhospitable desert region with long, extremely hot summers and short, very warm winters. The Erg Chech is a vast sandy expanse including compound and complex linear and star dunes. The mean elevation of the Erg Chech is just above 300 m, slightly lower than the neighboring Erg Iguidi stretching to the north. The barren plain of the Tanezrouft is located to the southeast. One of the localities of the commune of Akabli in Aoulef District, Adrar Province, Algeria, is named 'Erg Chech'. Meteorites About of meteorites were collected in the Chergach strewn field, located in the Erg Chech north of Taoudenni, during the fall and winter 2007. Desert nomads reported that during daytime in July 2007 several detonations were heard over a wide area, a smoke cloud was seen and several stones fell from the sky, however no fireball ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erg (landform)
An erg (also sand sea or dune sea, or sand sheet if it lacks dunes) is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The word is derived from the Arabic language, Arabic word ''ʿirq'' (), meaning "dune field". Strictly speaking, an erg is defined as a desert area that contains more than of aeolian processes, aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara, covers and contains several ergs, such as the Chech Erg and the Issaouane Erg in Algeria. Approximately 85% of all the Earth's mobile sand is found in ergs that are greater than , the largest being the Rub' al Khali, the ''Empty Quarter'' of the Arabian Peninsula. Ergs are also found on other celestial bodies, such as Venus, Mars, and Saturn's moon Titan (moon), Titan. Geography Sand seas and dune fields generally occur in regions downwind of copious sourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strewn Field
A strewn field is the area where meteorites from a single meteorite fall, fall are dispersed. It is also often used for the area containing tektite, tektites produced by a large meteorite impact.''Tektites in the geological record: showers of glass from the sky''. Gerald Joseph Home McCall. Geological Society of London, 2001page 10/ref> Formation There are two strewnfield formation mechanisms: # Mid-air fragmentation: when a large meteoroid enters the atmosphere it often fragments into many pieces before touching the ground due to thermal shock. This mid-air explosion disperses material over a large oval-shaped area. The long axis of this oval is along the flight path of the meteoroid. When multiple-explosions occur, the material can be found in several overlapping ovals. # Impact fragmentation: when there is almost no mid-air fragmentation the fragmentation can occur upon impact. In this case the strewnfield shape can be different, usually circular. Examples include the strewn fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deserts Of Algeria
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or Semi-arid climate, semi-arid. This includes much of the Polar regions of Earth, polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night strain the Rock (geology), rocks, which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting frag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ergs Of Africa
The erg is a unit of energy equal to 10−7joules (100 nJ). It is not an SI unit, instead originating from the centimetre–gram–second system of units (CGS). Its name is derived from (), a Greek word meaning 'work' or 'task'. An erg is the amount of work done by a force of one dyne exerted for a distance of one centimetre. In the CGS base units, it is equal to one gram centimetre-squared per second-squared (g⋅cm2/s2). It is thus equal to 10−7 joules or 100 nanojoules ( nJ) in SI units. * 1 erg = = * 1 erg = = = * 1 erg = = * 1 erg = = * 1 erg = History In 1864, Rudolf Clausius proposed the Greek word () for the unit of energy, work and heat. In 1873, a committee of the British Association for the Advancement of Science, including British physicists James Clerk Maxwell and William Thomson recommended the general adoption of the centimetre, the gramme, and the second as fundamental units ( C.G.S. System of Units). To distinguish derived units, they recommende ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Ergs
In geomorphology, an erg is a large desert region of sand dunes with little or no vegetation. It is divided into 3 parts: back erg, central erg, fore erg, especially in the Sahara. This is a list of ergs around the world. Africa ;Algeria * Grand Erg Oriental (extends into Tunisia) * Grand Erg Occidental (extends into Morocco) * Erg Chech (extends into Mali) * Erg Iguidi (extends into Mauritania) * Erg Issaouane * Erg er-Raoui * Erg Tiferine * Erg Tidohaine * Erg Merhiti * Erg Admer ; Botswana * Kalahari Desert ; Chad * Erg Djourab * Erg Idrisi ; Egypt * Black Desert * Erg Abunugar * Erg Abu Muharrik * Erg Abu Ramada * Gilf Kebir * Ramla el Kebir * Erg Somaya * Negev Desert (extends into Israel) * Great Sand Sea Desert * White Desert ; Libya * Erg Awbari * Erg Ubari * Erg Titersine * Erg Idehan Murzuq * Erg Ouan Kasa * Erg Tannezouft * Erg Takarkouri * Erg Mehedjibat * Erg Tassegefit * Calanshio Sand Sea * Rebiana Sand Sea ; Mali * Erg Achaif * Erg Aoukar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of Algeria
Algeria comprises of land, more than 80% of which is desert, in North Africa, between Morocco and Tunisia. It is the largest country in Africa. Its Arabic name, Al Jazair (the islands), is believed to derive from the rocky islands along the coastline of the Mediterranean Sea. The northern portion, an area of mountains, valleys, and plateaus between the Mediterranean and the Sahara Desert, forms an integral part of the section of North Africa known as the Maghreb. This area includes Morocco, Tunisia, and the northwestern portion of Libya known historically as Tripolitania. Size and boundaries Land boundaries:''Total:'' ''Border countries:'' Libya , Mali , Mauritania , Morocco , Niger , Tunisia , Western Sahara . Area – comparative: slightly larger than the Democratic Republic of the Congo and Saudi Arabia Coastline: Maritime claims: ''Territorial sea:'' , ''contiguous zone'': ''; exclusive fishing zone:'' Geographic regions The Tell The fertile Tell is the countr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuareg People
The Tuareg people (; also spelled Twareg or Touareg; Endonym and exonym, endonym, depending on Tuareg languages#Subclassification, variety: ''Imuhaɣ'', ''Imušaɣ'', ''Imašeɣăn'' or ''Imajeɣăn'') are a large Berbers, Berber ethnic group, traditionally nomadic pastoralism, pastoralists, who principally inhabit the Sahara in a vast area stretching from far southwestern Libya to southern Algeria, Niger, Mali, Burkina Faso, and as far as northern Nigeria, with small communities in Chad and Sudan known as the ''Kinnin''. The Tuareg speak Tuareg languages, languages of the same name, also known as ''Tamasheq'', which belong to the Berber languages, Berber branch of the Afroasiatic family. They are a semi-nomadic people who mostly practice Islam, and are descended from the indigenous Berber communities of Northern Africa, whose ancestry has been described as a mosaic of local North Africa, Northern African (Taforalt), Middle Eastern, Genetic history of Europe, European (Early Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Car Accident
A traffic collision, also known as a motor vehicle collision, or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other moving or stationary obstruction, such as a tree, pole or building. Traffic collisions often result in injury, disability, death, and property damage as well as financial costs to both society and the individuals involved. Road transport is statistically the most dangerous situation people deal with on a daily basis, but casualty figures from such incidents attract less media attention than other, less frequent types of tragedy. The commonly used term car accident is increasingly falling out of favor with many government departments and organizations: the Associated Press style guide recommends caution before using the term and the National Union of Journalists advises against it in their Road Collision Reporting Guidelines. Some collisions are intentional vehicle-ramming attacks, staged crashes, vehic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteoroid
A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classified as ''micrometeoroids'' or ''space dust''. Many are fragments from comets or asteroids, whereas others are impact event, collision impact space debris, debris ejected from bodies such as the Moon or Mars. The visible passage of a meteoroid, comet, or asteroid atmospheric entry, entering Earth's atmosphere is called a meteor, and a series of many meteors appearing seconds or minutes apart and appearing to originate from the same fixed point in the sky is called a meteor shower. An estimated 25 million meteoroids, micrometeoroids and other space debris enter Earth's atmosphere each day, which results in an estimated 15,000 tonnes of that material entering the atmosphere each year. A ''meteorite'' is the remains of a meteoroid that has surv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nomad
Nomads are communities without fixed habitation who regularly move to and from areas. Such groups include hunter-gatherers, pastoral nomads (owning livestock), tinkers and trader nomads. In the twentieth century, the population of nomadic pastoral tribes slowly decreased, reaching an estimated 30–40 million nomads in the world . Nomadic hunting and gathering—following seasonally available wild plants and game—is by far the oldest human subsistence method known. Pastoralists raise herds of domesticated livestock, driving or accompanying them in patterns that normally avoid depleting pastures beyond their ability to recover. Nomadism is also a lifestyle adapted to infertile regions such as steppe, tundra, or ice and sand, where mobility is the most efficient strategy for exploiting scarce resources. For example, many groups living in the tundra are reindeer herders and are semi-nomadic, following forage for their animals. Sometimes also described as "nomadic" are vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taoudenni
Taoudenni (also Taoudeni, Taoudénit, Taudeni, , ) is a remote salt mining center in the desert region of northern Mali, north of Timbuktu. It is the capital of Taoudénit Region. The salt is dug by hand from the bed of an ancient salt lake, cut into slabs, and transported either by truck or by camel to Timbuktu. The camel caravans ( azalai) from Taoudenni are some of the last that still operate in the Sahara Desert. In the late 1960s, during the regime of Moussa Traoré, a prison was built at the site and the inmates were forced to work in the mines. The prison was closed in 1988. Salt mining The earliest mention of Taoudenni is by al-Sadi, in his '' Tarikh al-Sudan'', who wrote that in 1586 when Moroccan forces attacked the salt mining center of Taghaza (150 km north west of Taoudenni) some of the miners moved to 'Tawdani'. In 1906, the French soldier Édouard Cortier visited Taoudenni with a unit of the camel corps ( méharistes) and published the first description o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chergach
Chergach is a meteorite found at southwest of El Mokhtar, Erg Chech, Timbuktu district, Mali. It fell on 2 or 3 July 2007, in daytime, and was composed of ordinary chondrite ( H5). History During 2007 fall and winter about of meteorites were collected in the Erg Chech, north of Taoudenni. Desert nomads reported that during daytime in July 2007 several detonations were heard over a wide area, a smoke cloud was seen and several stones fell from the sky, however no fireball was reported. Ouled Bleila was the finder of the first meteorites, but he died in October 2007 in a car accident on his way back from the trip to the Chergach strewn field. According to the Tuareg people, the elliptical strewn field stretches for more than . See also * Glossary of meteoritics This is a glossary of terms used in meteoritics, the science of meteorites. # * 2 Pallas – an asteroid from the asteroid belt and one of the likely parent bodies of the CR meteorites. * 4 Vesta – second-largest ast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
