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Summit Accordance
300px, The highest of hills in this picture show fairly similar heights making up a summit accordance. Aerial photograph from the Altai region of Russia. A summit accordance (sometimes also known by the German loan word gipfelflur) exists when hills and mountaintops, and eventually also plateaux, have such a disposition that they form a geometric plane that may be either horizontal or tilted. Summit accordances can be the vestiges of former continuous erosion surfaces that were uplifted and eroded. Other proposed explanations include: *the possibility that erosion becomes more effective at height, tearing down mountains that stand out *that isostasy regulates the height of individual mountain masses meaning that small mountains might be uplifted and large mountains dragged down *that landscape dissection by uniformly spaced streams eventually reach a state in which summits attain similar heights *that summit accordance is derivative of structural planes exposed by erosion See a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altai Mountains Aerial (6073002773)
Altai or Altay may refer to: Places *Altai Mountains, in Central and East Asia, a region shared by China, Mongolia, Kazakhstan and Russia In China *Altay Prefecture (阿勒泰地区), Xinjiang Uyghur Autonomous Region, China *Altay City (阿勒泰市), also spelled "Aletai", a city of Altay Prefecture In Kazakhstan * Altai Town, a town in Kazakhstan, until 2019 known as Zyryan or Zyryanovsk In Mongolia *Altai City *Altai, Govi-Altai, a ''sum'' (district) *Altai, Bayan-Ölgii, a ''sum'' *Altai, Khovd, a ''sum'' In Russia *Altai Krai, a federal subject of Russia **Altay, Altay Krai *Altai Republic, a federal subject of Russia People and languages *Altay (name), a list of people with the given name or surname *Altai people, an ethnic group **Altai languages, the languages spoken by these people Other uses *''Wu Ming#Altai, Altai'', a historical novel by Wu Ming *Rupes Altai, a feature of the geography of the Moon *Altay sheep, a sheep breed *Altay S.K., a football club from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plateau
In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides have deep hills or escarpments. Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, and erosion by water and glaciers. Plateaus are classified according to their surrounding environment as intermontane, piedmont, or continental. A few plateaus may have a small flat top while others have wide ones. Formation Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, Plate tectonics movements and erosion by water and glaciers. Volcanic Volcanic plateaus are produced by volcanic activity. The Columbia Plateau in the north-western United States is an example. They may be formed by upwelling of volcanic magma or extrusion of lava. The un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plane (geometry)
In mathematics, a plane is a Euclidean (flat), two-dimensional surface that extends indefinitely. A plane is the two-dimensional analogue of a point (zero dimensions), a line (one dimension) and three-dimensional space. Planes can arise as subspaces of some higher-dimensional space, as with one of a room's walls, infinitely extended, or they may enjoy an independent existence in their own right, as in the setting of two-dimensional Euclidean geometry. Sometimes the word ''plane'' is used more generally to describe a two-dimensional surface, for example the hyperbolic plane and elliptic plane. When working exclusively in two-dimensional Euclidean space, the definite article is used, so ''the'' plane refers to the whole space. Many fundamental tasks in mathematics, geometry, trigonometry, graph theory, and graphing are performed in a two-dimensional space, often in the plane. Euclidean geometry Euclid set forth the first great landmark of mathematical thought, an axiomatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion Surface
In geology and geomorphology, an erosion surface is a surface of rock or regolith that was formed by erosion and not by construction (e.g. lava flows, sediment deposition) nor fault displacement. Erosional surfaces within the stratigraphic record are known as unconformities, but not all unconformities are buried erosion surfaces. Erosion surfaces vary in scale and can be formed on a mountain range or a rock. Particularly large and flat erosion surfaces receive the names of peneplain, paleoplain, planation surface or pediplain. An example of erosion surface is road surface erosion which is caused by natural and anthropogenic factors. Erosion surface can be measured through direct, contact measurement methods and indirect, non-contact measurement methods. Road surface erosion Just like mountains and rocks, erosion can also occur on unsealed roads due to natural and anthropogenic factors. Road surface erosion could be caused by snowfall, rainfall and wind. The material and hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion procee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nationalencyklopedin
''Nationalencyklopedin'' (; "The National Encyclopedia" in English), abbreviated NE, is a comprehensive contemporary Swedish-language encyclopedia, initiated by a favourable loan from the Government of Sweden of 17 million Swedish kronor in 1980, which was repaid by December 1990. The printed version consists of 20 volumes with 172,000 articles; the Internet version comprises 260,000 articles (as of June 2005). History The project was born in 1980, when a government committee suggested that negotiations be initiated with various publishers. This stage was finished in August 1985, when in Höganäs became the publisher responsible for the project. The project specifications were for a modern reference work based on a scientific paradigm incorporating gender and environmental issues. Pre-orders for the work were unprecedented; before the first volume was published in December 1989, 54,000 customers had ordered the encyclopedia. The last volume came out in 1996, with three suppl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isostasy
Isostasy (Greek ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its thickness and density. This concept is invoked to explain how different topographic heights can exist at Earth's surface. Although originally defined in terms of continental crust and mantle, it has subsequently been interpreted in terms of lithosphere and asthenosphere, particularly with respect to oceanic island volcanoes, such as the Hawaiian Islands. Although Earth is a dynamic system that responds to loads in many different ways, isostasy describes the important limiting case in which crust and mantle are in static equilibrium. Certain areas (such as the Himalayas and other convergent margins) are not in isostatic equilibrium and are not well described by isostatic models. The general term 'isostasy' was coined in 1882 by the Ameri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Geology
Structural geology is the study of the three-dimensional distribution of rock units with respect to their deformational histories. The primary goal of structural geology is to use measurements of present-day rock geometries to uncover information about the history of deformation (strain) in the rocks, and ultimately, to understand the stress field that resulted in the observed strain and geometries. This understanding of the dynamics of the stress field can be linked to important events in the geologic past; a common goal is to understand the structural evolution of a particular area with respect to regionally widespread patterns of rock deformation (e.g., mountain building, rifting) due to plate tectonics. Use and importance The study of geologic structures has been of prime importance in economic geology, both petroleum geology and mining geology. Folded and faulted rock strata commonly form traps that accumulate and concentrate fluids such as petroleum and natural gas. Simil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissected Plateau
A dissected plateau is a plateau area that has been severely eroded such that the relief is sharp. Such an area may be referred to as mountainous, but dissected plateaus are distinguishable from orogenic mountain belts by the lack of folding, metamorphism, extensive faulting, or magmatic activity that accompanies orogeny. Formation A dissected plateau may also be formed, or created, usually on a comparatively small scale, by the levelling of terrain by planing and deposition beneath an ice sheet or perhaps, an ice cap. Subsequently, during the same or a later glacial, the margins of the glacial till plain are removed by glaciers, leaving the plateau into which erosion by water incises valleys. Such a plateau may be level or gently sloping but may be distinguished by the till caps on its hills. Glacial till is still widely known in Britain by the older name of boulder clay. Dissected volcanic plateaus include the Pajarito Plateau in New Mexico, on the skirt of the enormous Va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Buzzsaw
The glacial buzzsaw is a hypothesis claiming erosion by warm-based glaciers is key to limit the height of mountains above certain threshold altitude. To this the hypothesis adds that great mountain massifs are leveled towards the equilibrium line altitude (ELA), which would act as a “climatic base level”. Starting from the hypothesis it has been predicted that local climate restricts the maximum height that mountain massifs can attain by effect of uplifting tectonic forces. It follows that as local climate is cooler at higher latitudes the highest mountains are lower there compared to the tropics where glaciation is and has been more limited. The mechanism behind the glacial buzzsaw effect would be the erosion of small glaciers that are mostly unable to erode much below the equilibrium line altitude since they do not reach these altitudes because of increased ablation. Instead, large valley glaciers may easily surpass the equilibrium line altitude and do therefore not contribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syrt
A syrt is a kind of an elevated landform in Russia and Central Asia. The word means "highland", "ridge" or "backbone" in Turkic languages (''sırt'') and is present in Turkic toponymy in the mentioned areas: in Tien Shan, Pamirs, South Urals, such as Obshchiy Syrt by Urals, Uzun-Syrt ("Long back") plateau by Koktebel in Crimea. It is a denudational upland or elevated flatland, a kind of dissected plateau. Syrts may be separated from each other by higher ridges. At the same time, syrts may serve as water divides between drainage basins for larger rivers. The term should not to be confused with the Latin term '' syrtis'' and the derived term "syrt" for sandy shores or quicksand Quicksand is a colloid consisting of fine granular material (such as sand, silt or clay) and water. It forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that los .... See also * Summit accordance References {{reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
