mountain
A mountain is a landform that rises above the surrounding area. It is usually higher and steeper than a hill , although there is no definition for the exact differentiation and delimitation of the two types of terrain. A mountain should be characterized by a certain independence, i.e. have sufficient distance from other mountains and a minimum height above a pass . The counterpart is the valley .
Geologically and geographically related mountains form a mountain range or a mountain range . A distinction is made between high and low mountain ranges . Isolated mountains are called Inselberg .
The naming of a terrain form by humans as an independent mountain is subjective and not sharply delimited from the term summit . The only thing that is clear is that there are more peaks than mountains. Normally a mountain will have a main and several secondary peaks , since according to the definition of the mountaineering associations a counter-climb of 30 meters is sufficient for a peak.
etymology
The Common Germanic word Middle High German berc , Old High German berg, is based on Indo-European bherḡos- 'mountain' (root form: bhereḡh- 'high, raised', an extension of bher [ɘ] - '[to] lift, [to] rain' → to give birth ). The term is part of the Swadesh list .
Criteria for independence
Possible indications of whether a mountain is to be regarded as independent or as a secondary peak of a neighboring higher mountain are its dominance and its notch height . A list of common criteria can be found under mountain peaks .
What is considered “high” in a mountain is always relative to the surrounding landscape. The North German Dammer (115 to 146 meters) or Hüttener Berge (92 to 106 meters) would only be considered hills in Switzerland, for which the border in Germany or Austria is set at around 300 meters. The Møllehøj as Denmark's highest peak measures just 170 meters, and the Wilseder mountain towers over 169 meters above sea level. NN not only the Lüneburg Heath , but all natural elevations within a radius of 100 kilometers.
The notch height and the dominance of an elevation can be used as criteria to classify a summit as an independent mountain. In the high mountains, for example, a notch height of around 100 to 300 meters and a dominance of around one to three kilometers are the minimum dimensions to speak of an independent mountain.
to form
Mountains can be rounded as a hilltop , or as a mountain top or horn, pointed and rugged like a pyramid. In the case of a table mountain or chair , the height can be flat like a plateau. The mountain can be elongated as a ridge , but can also form the starting point for several branching ridges. Mountains can stand freely in the landscape (such as Israel's Mount Tabor ), but are usually part of a mountain range .
climate
Depending on the sun and wind exposure as well as the geographical latitude, different climatic conditions prevail on a mountain, which in turn influence the vegetation. The slopes facing the sun are warmer than those in the shade. Depending on the height of the mountain, there are several height levels with different climates on its flanks .
Recreational use
Mountains have been discovered as " sports equipment " for alpinism since the 19th century ; in the course of the 20th century, extreme climbing and free climbing emerged parallel to traditional mountaineering . Other mountain sports species found numerous followers, about Ski ride, snowboarding or ski touring .
Mountains stand for stability and immutability and in this sense are mentioned in many proverbs : "If the mountain does not come to the prophet, the prophet must go to the mountain". Many people feel “ closer to heaven ” on the mountain , and this experience stimulates reflection or prayer . As a “ladder to God ”, many low to medium-high mountains therefore have a chapel or memorial. In the high mountains of Europe and America they usually carry a summit cross .
Many mountains are known or popular for their panoramic views . If this is obstructed by the forest, a lookout point is built . Often survey points or, better, trigonometric points close to the summit are essential.
Formation of mountains
Mountains are usually a result of the earth's plate tectonics or are of volcanic origin. If two plates of the earth's crust move against each other, a mountain range is often pushed up at the “crumple zone” . Their mountains are characterized by their rugged shape and great height. Outstanding examples are the mountains of the Himalayas and the Andes , but also those of the Alps , the Balkan mountains and the Zagros .
With increasing geological age, erosion contributes to the fact that the forms become milder and the mountains lower. The German low mountain ranges offer examples of this .
Recent research suggests that the prerequisites for the formation of higher mountains were given for the first time in the Neo-Archean . In the ages before that, the continental lithosphere was not sufficiently stable for topographic elevations of more than 2,500 meters due to its high temperature and insufficient thickness .
Some steep slopes in the high mountains make it clear that stone is quite malleable: there are mountain folds of hundreds of meters and layers that are bent like a stack of paper. Almost every rock gives way if the annual movement is only a few millimeters. It reacts brittle to faster forces - comparable to sealing wax - and breaks.
Often brings tectonics or erosion the various rock types from which many mountains exist to light what interesting geological or paleontological even (in the form of fossils may allow) insights. Also ores and mines are a sign of this diversity. Often over were Earth's history to older mountain sandstone layers or reefs attached ( Jura , Dachstein Mountains , Leitha Mountains , Westerwald ).
In the area of subduction zones , where one plate of the earth is pushed under another, the lower one is melted. The hot melt is lighter than its surroundings and penetrates upwards. This is one of the causes of volcanism , which is also responsible for the formation of many mountains. Active and former fire-breathing mountains are called volcanoes.
A mountain formation that occurs in areas near the poles is that of relief reversal : a hollow is filled with scree by glaciers , whereby the ground is under pressure from the weight of the ice . If the glaciers retreat, the subsoil relaxes, and the scree filling can partially be lifted above the surrounding area. Elevations created in this way can be observed , for example, on the Münsterland gravel sand pull . On the other hand, it is more common to observe that older mountain layers remain standing due to their greater hardness , while younger ones weather faster.
Mountains can hardly rise higher than nine kilometers on earth . This is because the base of a mountain liquefies from this height due to the enormous lithostatic pressure and so the maximum height is determined.
"Floating" mountains and gravity
"Young" mountains virtually swim on the earth's mantle because the density of their rocks (around 2.5 to 3 g / cm³) is lower than in the basalt-like subsoil (density around 3.3 g / cm³). In this way, one could compare mountain regions with floating icebergs , but their “swimming equilibrium” is only 90 to 95 percent ( isostasy ). When immersed, they displace denser rocks , creating gravity anomalies . These anomalies can be investigated with methods of geophysics and geodesy and thus the interior of the earth can be explored.
“Older” mountain chains, on the other hand, are more worn away and have sunk a bit as a result, so that they are almost 100 percent in hydrostatic equilibrium with their surroundings . Measurements of the earth's gravity field no longer show any greater effect here.
Movies
- Planet earth . Mountain worlds. (OT: Mountains ) Great Britain, documentary, 45 min., A film by Alastair Fothergill , production: BBC , 2006, summary ( memento from March 12, 2007 in the Internet Archive ) by ARD
Mountains according to height
- Highest mountain - superlatives according to various definitions and constraints
- List of highest points by country
- Eight-thousanders , four-thousanders , three-thousanders , two-thousanders
- Seven Summits , the highest mountains on each of the seven continents
See also
- Mountainous country
- Mountain pass (often referred to as "mountain", e.g. Arlberg , Monte Ceneri , Montgenèvre and others)
- Gora , (Russian and Serbo-Croatian for "mountain") or Góra (Polish and Lower Sorbian for "mountain")
- Vrchovina , the Czech word for mountainous country or hill country
Web links
- Literature on the subject of mountains in the catalog of the German National Library
- Answer to the question: what is a mountain?
Individual evidence
- ^ The dictionary of origin (= Der Duden in twelve volumes . Volume 7 ). Reprint of the 2nd edition. Dudenverlag, Mannheim 1997, p. 74 ( limited preview in Google Book search). See also DWDS ( "Berg" ) and Friedrich Kluge : Etymological dictionary of the German language . 7th edition. Trübner, Strasbourg 1910 ( p. 48 ).
- ↑ Rey, P. and Coltitce, N. (2008): Neoarchean lithospheric strengthening and the coupling of Earth's geochemical reservoirs. ( Memento of the original from June 9, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. In: Geology Vol. 36, pp. 635-638.
