Editing Plateau

{{Short description|Highland area, usually of relatively flat terrain}}
{{Other uses}}
{{More citations needed|date=June 2010}}

[[File:Himalaya 85.30820E 32.11063N.jpg|thumb|upright=1.25|Satellite image of the [[Tibetan Plateau]] between the Himalayan mountains to the south and the [[Taklamakan Desert]] to the north]]

In [[geology]] and [[physical geography]], a '''plateau''' ({{IPAc-en|p|l|ə|ˈ|t|oʊ|,_|p|l|æ|ˈ|t|oʊ|,_|ˈ|p|l|æ|t|oʊ}}; {{IPA|fr|plato|lang}}; {{plural form}}: '''plateaus''' or '''plateaux'''),<ref name="Merriam-Webster">{{cite Merriam-Webster|plateau|access-date=2017-08-26}}</ref><ref name="Cambridge">{{cite web |url=https://dictionary.cambridge.org/dictionary/english/plateau |title=plateau |publisher=[[Cambridge University Press]] |work=[[Cambridge English Dictionary]] |access-date=2017-08-26}}</ref> 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.{{sfn|Huggett|2011|p=99|loc=Plate Tectonics and Associated Structural Landforms}} Often one or more sides have deep hills or [[escarpment]]s.{{sfn|Huggett|2011|p=124|loc=Volcanoes, Impact Craters, Folds, and Faults}} Plateaus can be formed by a number of processes, including [[upwelling]] of [[volcano|volcanic]] [[magma]], [[extrusion]] of [[lava]], and [[erosion]] by water and [[glacier]]s. 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 wider 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 ===
{{Main|Volcanic plateau}}
[[File:Pajarito Plateau.jpg|thumb|The [[Pajarito Plateau]] in New Mexico is an example of a volcanic plateau.]]
[[Volcanic plateau]]s are produced by [[volcanism|volcanic activity]]. They may be formed by upwelling of volcanic magma or extrusion of lava. The underlining mechanism in forming plateaus from upwelling starts when magma rises from the [[mantle (geology)|mantle]], causing the ground to swell upward. In this way, large, flat areas of rock are uplifted to form a plateau. For plateaus formed by extrusion, the rock is built up from lava spreading outward from cracks and weak areas in the crust. The [[County Antrim#Geography|Antrim Plateau]] in [[Northern Ireland]], the [[Deccan Plateau]] in [[India]], the [[Big Raven Plateau]] in Canada, and the [[Columbia Plateau]] in the [[United States]] are examples of lava plateaus.

=== Tectonic ===
Tectonic plateaus are formed by tectonic plate movements which cause uplift, and are normally of a considerable size, and a fairly uniform altitude. Examples are the [[Deccan Plateau]] in [[India]] and the [[Meseta Central]] on the [[Iberian Peninsula]].<ref name=":0" />

=== Erosion ===
Plateaus can also be formed by the erosional processes of [[glacier]]s on mountain ranges, leaving them sitting between the mountain ranges. Water can also erode mountains and other landforms down into plateaus. [[Dissected plateau]]s are highly eroded plateaus cut by rivers and broken by deep narrow valleys. An example is the [[Scottish Highlands]].<ref>{{cite journal|last=Garcia-Castellanos |first=D. |date=2007 |title=The role of climate during high plateau formation. Insights from numerical experiments. |journal=[[Earth and Planetary Science Letters]] |volume=257 |issue=3–4 |pages=372–390 |doi=10.1016/j.epsl.2007.02.039 |bibcode=2007E&PSL.257..372G |url=https://docs.google.com/uc?id=0B_xuyENh5ksFMzdiZjg0NGUtNWQ5Zi00YTU0LThkODctODA3ZWMxYjAzNTI2&export=download&hl=en|url-access=subscription }}</ref>

== Classification ==
Plateaus are classified according to their surrounding environment.

* Intermontane plateaus are some of the highest and most extensive plateaus in the world, enclosed by fold mountains. Examples are the [[Tibetan Plateau]] between the [[Himalayas]] and [[Kunlun Mountains]], and the [[Altiplano]] plateau between two ranges of the [[Andes]].<ref name=":0">{{Cite book|last=Leong |first=Goh Cheng |url=https://books.google.com/books?id=XhJ4RAAACAAJ&q=certificate+physical+and+human+geography |title=Certificate Physics And Human Geography |edition=Indian |date=1995-10-27 |publisher=[[Oxford University Press]] |isbn=978-0-19-562816-6 |pages=17 |language=en}}</ref>
* Piedmont plateaus are bordered on one side by mountains and on the other by a plain or a sea. The [[Piedmont (United States)|Piedmont Plateau]] of the [[Eastern United States]] between the [[Appalachian Mountains]] and the [[Atlantic Plain]] is an example.
* Continental plateaus are bordered on all sides by plains or oceans, forming away from the mountains. An example of a continental plateau is the [[Antarctic Plateau]] in [[East Antarctica]].

== Large plateaus by continent ==
=== Africa ===
The highest African plateau is the [[Ethiopian Highlands]] which cover the central part of Ethiopia. It forms the largest continuous area of its altitude in the continent, with little of its surface falling below 1,500 metres (4,921 ft), while the summits reach heights of up to 4,556 metros(14,928 ft). It is sometimes called the Roof of Africa due to its height and large area

Another example is the [[Highveld]] which is the portion of the South African inland plateau which has an altitude above approximately 1,500 metres, but below 2,100 metres, thus excluding the Lesotho mountain regions. It is home to some of the largest South African [[urban area|urban agglomerations]].

In Egypt are the [[Giza Plateau]]<ref>{{cite book|title=The Ibis|url=https://books.google.com/books?id=ML5HAQAAIAAJ&pg=PA206|year=1906|pages=206–}}</ref> and [[Galala Mountain]], which was once called Gallayat Plateaus, rising 3,300 ft above sea level.<ref name="MikhailMoussa2009">{{cite book|first1=Maged S. A. |last1=Mikhail |first2=Mark |last2=Moussa |title=Christianity and Monasticism in Wadi Al-Natrun: Essays from the 2002 International Symposium of the Saint Mark Foundation and the Saint Shenouda the Archimandrite Coptic Society |url=https://books.google.com/books?id=4eBv2vuo7lYC&pg=PA63 |year=2009 |publisher=American Univ in Cairo Press |isbn=978-977-416-260-2 |pages=63–}}</ref>

=== Antarctica ===
Another very large plateau is the icy [[Antarctic Plateau]], which is sometimes referred to as the Polar Plateau or [[Haakon VII of Norway|King Haakon VII]] Plateau, home to the geographic [[South Pole]] and the [[Amundsen–Scott South Pole Station]], which covers most of [[East Antarctica]] where there are no known mountains but rather {{Convert|3000|m|abbr=on}} high of superficial ice and which spreads very slowly toward the surrounding coastline through enormous [[glacier]]s. The [[polar ice cap]] is so massive that the [[Sonar|echolocation]] measurements of ice thickness have shown that large areas are below [[sea level]]. But, as the ice melts, the land beneath will [[Post-glacial rebound|rebound]] through [[isostasy]] and ultimately rise above sea level.{{Citation needed|date=June 2020}}

=== Asia ===
The largest and highest plateau in the world is the [[Tibetan Plateau]], sometimes metaphorically described as the "[[Roof of the World]]", which is still being formed by the collisions of the [[Indo-Australian Plate|Indo-Australian]] and [[Eurasian Plate|Eurasian]] [[plate tectonics|tectonic plates]]. The Tibetan Plateau covers approximately {{Convert|2500000|km2|abbr=on}}, at about {{Convert|5000|m|abbr=on}} above sea level. The plateau is sufficiently high to reverse the [[Hadley cell]] convection cycles and to drive the [[Monsoon of South Asia|monsoons of India]] towards the south. The [[Deosai National Park|Deosai Plains]] in Pakistan are situated at an average elevation of 4,114 meters (13,497 ft) above sea level. They are considered to be the second highest plateaus in the world.

Other major plateaus in Asia are: [[Najd]] on the [[Arabian Peninsula]], elevation 762 to 1,525 m (2,500 to 5,003 ft), [[Armenian Highlands]] (≈{{Convert|400000|km2|abbr=on}}, elevation {{convert|900-2100|m|ft}}), [[Iranian Plateau]] (≈{{Convert|3700000|km2|abbr=on}}, elevation {{convert|300-1500|m|ft}}), [[Anatolian Plateau]], [[Mongolian Plateau]] (≈{{Convert|2600000|km2|abbr=on}}, elevation {{convert|1000–1500|m|ft}}), and the [[Deccan Plateau]] (≈{{Convert|1900000|km2|abbr=on}}, elevation {{convert|300-600|m|ft}}).

=== North America ===
A large plateau in North America is the [[Colorado Plateau]], which covers about {{convert|337000|km2|abbr=on}} in [[Colorado]], [[Arizona]], [[New Mexico]], and [[Utah]].<ref>{{cite web |last=Leighty |first=Robert D. |title=Colorado Plateau Physiographic Province |work=Contract Report |publisher=Defense Advanced Research Projects Agency (DOD) Information Sciences Office |year=2001 |url=http://www.tec.army.mil/publications/ifsar/lafinal08_01/five/5.1.5_frame.htm |access-date=2007-12-25 |url-status=dead |archive-url=https://web.archive.org/web/20040926200513/http://www.tec.army.mil/publications/ifsar/lafinal08_01/five/5.1.5_frame.htm |archive-date=2004-09-26}}</ref>

In northern Arizona and southern Utah the Colorado Plateau is [[wikt:bisect|bisected]] by the [[Grand Canyon]] of the [[Colorado River]]. This came to be over 10 million years ago, the river was already there, though not necessarily on exactly the same course. Then, subterranean geological forces caused the land in that part of North America to gradually rise by about a centimeter per year for millions of years. An unusual balance occurred: the river that would become the Colorado River was able to erode into the crust of the Earth at a nearly equal rate to the uplift of the plateau. Now, millions of years later, the North Rim of the Grand Canyon is at an elevation of about {{Convert|2450|m|abbr=on}} above [[sea level]], and the South Rim of the Grand Canyon is about {{Convert|2150|m|abbr=on}} above sea level. At its deepest, the Colorado River is about {{Convert|1830|m|abbr=on}} below the level of the North Rim.

Another high-altitude plateau in North America is the [[Mexican Plateau]]. With an area of {{Convert|601882|km2|abbr=on}} and average height of 1,825 metres, it is the home of more than 70 million people.

=== Oceania ===
The [[Western Plateau]], part of the [[Australian Shield]], is an ancient [[craton]] covering much of the continent's southwest, an area of some 700,000 square kilometres. It has an average elevation between 305 and 460 metres.

The [[North Island Volcanic Plateau]] is an area of high land occupying much of the centre of the [[North Island]] of New Zealand, with volcanoes, lava plateaus, and crater lakes, the most notable of which is the country's largest lake, [[Lake Taupō]]. The plateau stretches approximately 100 km east to west and 130 km north to south. The majority of the plateau is more than 600 metres above sea level.

The [[Northern Tablelands]] are the largest highland area in Australia, covering approximately 18,197 square kilometres. There are widespread high points over 1,000 metres including The Brothers (1,508m), Ben Lomond (1,505m), Mount Rumbee (1,503m), Point Lookout (1,564m), Campoompeta (1,510m), Mount Spirabo (1,492m), Mount Mitchell (1,475m), Chandler's Peak (1,471m), Mount Grundy (1,462m), Mount Bajimba (1,448 m) and the highest point at Round Mountain is 1,584 metres above sea level. The now closed railway station at Ben Lomond, was the highest railway station in Australia. Apart from Antarctica it is the most extensive highland region in the Southern Hemisphere with an average elevation of over 1,000 metres.

=== South America ===
[[File:The Road to the Stars.jpg|thumb|Road to the [[Atacama Large Millimeter Array|ALMA]]'s Operations Support Facility and then on further to the [[Llano de Chajnantor Observatory|Chajnantor Plateau]] at 5,000 metres above sea level.<ref>{{cite web|title=The Road to the Stars |url=http://www.eso.org/public/images/potw1530a/ |access-date=27 July 2015}}</ref>]]

The parallel Sierra of Andes delimit one of the world highest plateaux: the [[Altiplano]], (Spanish for "high plain"), Andean Plateau or Bolivian Plateau. It lies in west-central South America, where the Andes are at their widest, is the most extensive area of high plateau on Earth outside of Tibet. The bulk of the Altiplano lies within Bolivian and Peruvian territory while its southern parts lie in Chile. The Altiplano plateau hosts several cities like Puno, Oruro, El Alto and La Paz the administrative seat of Bolivia. Northeastern Altiplano is more humid than the Southwestern, the latter of which hosts several ''salares'', or salt flats, due to its aridity. At the Bolivia-Peru border lies [[Lake Titicaca]], the largest lake in South America.

The Colombian capital city of Bogota sits on another Andean plateau known as the [[Altiplano Cundiboyacense]] roughly the size of Switzerland. Averaging a height of {{Convert|2600|m|ft|abbr=on}} above sea level, this northern Andean plateau is situated in the country's eastern range and is divided into three main flat regions: the [[Bogotá savanna]], the valleys of [[Ubaté]] and [[Chiquinquirá]], and the valleys of [[Duitama]] and [[Sogamoso]].

== See also ==
* {{annotated link|Atherton Tableland}}
* {{annotated link|Butte}}
* {{annotated link|Chapada}}
* {{annotated link|Deosai National Park}}
* {{annotated link|Mesa}}
* {{annotated link|Oceanic plateau}}
* {{annotated link|Potrero (landform)|Potrero}}
* {{annotated link|Tuya}}

== References ==
{{Reflist}}

=== Bibliography ===
* {{Cite book |last=Huggett |first=Richard John |title=Fundamentals Of Geomorphology |edition=3rd |series=Routledge Fundamentals of Physical Geography Series |publisher=[[Routledge]] |date=2011 |isbn=978-0-203-86008-3}}

== External links ==
{{Commons category-inline|Plateaus}}
{{EB1911 Poster|Plateau}}
* [http://www.scienceclarified.com/landforms/Ocean-Basins-to-Volcanoes/Plateau.html "Plateau" at scienceclarified.com]
* [https://web.archive.org/web/20080111042546/http://science.nationalgeographic.com/science/earth/surface-of-the-earth/plateaus-article.html nationalgeographic.com]
* [https://web.archive.org/web/20070913213321/http://www.travel-university.org/general/geography/landforms/plateaus.html travel-university.org]
* [http://www.britannica.com/EBchecked/topic/463959/plateau britannica.com]

{{Earth's landforms}}
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[[Category:Plateaus| ]]
[[Category:Slope landforms]]