|
Ténéré - Aïr Natural Reserve
The Ténéré (Tuareg languages, Tuareg: Tenere, literally: "desert") is a desert region in south central Sahara. It comprises a vast plain of sand stretching from northeastern Niger to western Chad, occupying an area of over . The Ténéré's boundaries are said to be the Aïr Mountains in the west, the Hoggar Mountains in the north, the Djado Plateau in the northeast, the Tibesti Mountains in the east, and the basin of Lake Chad in the south. The central part of the desert, the Erg du Bilma, is centred at approximately . It is the locus of the Neolithic Tenerian culture. Name The name ''Ténéré'' comes from the Tuareg languages, Tuareg language, meaning "desert", in much the same way as the Arabic language, Arabic word for "desert", ''Sahara'', came to be applied to the region as a whole. Climate The Ténéré has a hot desert climate (Köppen climate classification ''BWh''), typical of the large Sahara Desert. The climate is hyper-arid, extremely hot, sunny and dry year-rou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desert
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] |
Neolithic
The Neolithic or New Stone Age (from Ancient Greek, Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the History of agriculture, introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of sedentism, settlement. The term 'Neolithic' was coined by John Lubbock, 1st Baron Avebury, Sir John Lubbock in 1865 as a refinement of the three-age system. The Neolithic began about 12,000 years ago, when farming appeared in the Epipalaeolithic Near East and Mesopotamia, and later in other parts of the world. It lasted in the Near East until the transitional period of the Chalcolithic (Copper Age) from about 6,500 years ago (4500 BCE), marked by the development ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erg Of Bilma
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] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering Water distribution on Earth, 70.8% of Earth's crust. The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere. Most of Earth's land is at least somewhat humid and covered by vegetation, while large Ice sheet, sheets of ice at Polar regions of Earth, Earth's polar polar desert, deserts retain more water than Earth's groundwater, lakes, rivers, and Water vapor#In Earth's atmosphere, atmospheric water combined. Earth's crust consists of slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's outer core, Earth has a liquid outer core that generates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Desert
The Sahara (, ) is a desert spanning across North Africa. With an area of , 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 , a broken plural form of ( ), 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 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States's civil list of government space agencies, space program, aeronautics research and outer space, space research. National Aeronautics and Space Act, Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion (spacecraft), Orion spacecraft and the Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sahara Desert
The Sahara (, ) is a desert spanning across North Africa. With an area of , it is the largest hot desert in the world and the list of deserts by area, third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic. The name "Sahara" is derived from , a broken plural form of ( ), 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, 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 the landscape gradually changes from desert to coastal plains. To the south it is bounded by the Sahel, a belt of Tropical and subtropical grasslands, savannas, and shrublands, semi-arid tropical savanna around the Niger River valley and the Sudan (region), Sudan region of sub-Saharan Africa. The Sahara can be divided into several regions, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Köppen Climate Classification
The Köppen climate classification divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (temperate), ''D'' (continental), and ''E'' (polar). Each group and subgroup is represented by a letter. All climates are assigned a main group (the first letter). All climates except for those in the ''E'' group are assigned a seasonal precipitation subgroup (the second letter). For example, ''Af'' indicates a tropical rainforest climate. The system assigns a temperature subgroup for all groups other than those in the ''A'' group, indicated by the third letter for climates in ''B'', ''C'', ''D'', and the second letter for climates in ''E''. Other examples include: ''Cfb'' indicating an oceanic climate with warm summers as indicated by the ending ''b.'', while ''Dwb'' indicates a semi-Monsoon continental climate, monsoonal continental climate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Desert Climate
The desert climate or arid climate (in the Köppen climate classification ''BWh'' and ''BWk'') is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert climates are dry and hold little moisture, quickly evaporating the already little rainfall they receive. Covering 14.2% of Earth's land area, hot deserts are the second-most common type of climate on Earth after the Polar climate. There are two variations of a desert climate according to the Köppen climate classification: a hot desert climate (''BWh''), and a cold desert climate (''BWk''). To delineate "hot desert climates" from "cold desert climates", a mean annual temperature of is used as an isotherm so that a location with a ''BW'' type climate with the appropriate temperature above this isotherm is classified as "hot arid subtype" (''BWh''), and a location with the appropriate temperature below the isotherm is classified as "cold ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
