View source for Earth:Plateau

{{Short description|Highland area, usually of relatively flat terrain}}

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

In [[Earth:Geology|geology]] and [[Earth:Physical geography|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={{wipe|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 [[Earth:Highland|highland]] consisting of flat [[Terrain|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 [[Earth:Escarpment|escarpment]]s.{{sfn|Huggett|2011|p=124|loc=Volcanoes, Impact Craters, Folds, and Faults}} Plateaus can be formed by a number of processes, including [[Earth:Upwelling|upwelling]] of [[Earth:Volcano|volcanic]] [[Biology:Magma|magma]], [[Chemistry:Extrusion|extrusion]] of [[Earth:Lava|lava]], and [[Earth:Erosion|erosion]] by water and [[Earth:Glacier|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, [[Earth:Plate tectonics|plate tectonics]] movements, and erosion by water and glaciers.

=== Volcanic ===
{{Main|Earth:Volcanic plateau}}
[[File:Pajarito Plateau.jpg|thumb|The [[Earth:Pajarito Plateau|Pajarito Plateau]] in New Mexico is an example of a volcanic plateau.]]
[[Earth:Volcanic plateau|Volcanic plateau]]s are produced by volcanic activity. The [[Earth:Columbia Plateau|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 underlining mechanism in forming plateaus from upwelling starts when magma rises from the [[Earth: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.

=== 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 {{wipe|India}} and the Meseta Central on the [[Place:Iberian Peninsula|Iberian Peninsula]].<ref name=":0" />

=== Erosion ===
Plateaus can also be formed by the erosional processes of [[Earth:Glacier|glacier]]s on mountain ranges, leaving them sitting between the mountain ranges. Water can also erode mountains and other landforms down into plateaus. [[Earth:Dissected plateau|Dissected plateau]]s are highly eroded plateaus cut by rivers and broken by deep narrow valleys. An example is the [[Place:Scottish Highlands|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:Earth and Planetary Science Letters|Earth and Planetary Science Letters]] |volume=257 |pages=372–390 |doi=10.1016/j.epsl.2007.02.039 |url=https://docs.google.com/uc?id=0B_xuyENh5ksFMzdiZjg0NGUtNWQ5Zi00YTU0LThkODctODA3ZWMxYjAzNTI2&export=download&hl=en}}</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 [[Place:Tibetan Plateau|Tibetan Plateau]] between the Himalayas and Kunlun Mountains, Altiplano plateau between two ranges of [[Place:Andes|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=[[Organization:Oxford University Press|Oxford University Press]] |isbn=978-0-19-562816-6 |pages=17 |language=en}}</ref>
* Lava or volcanic plateaus are the plateau that occur in areas of widespread volcanic eruptions. The magma that comes out through narrow cracks or fissures in the crust spread over large area and solidifies. These layers of lava sheets form lava or volcanic plateaus. The Antrim Plateau in Northern Ireland, the Deccan Plateau in {{wipe|India}}, and the [[Earth:Columbia Plateau|Columbia Plateau]] in the {{wipe|United States}} are examples of lava plateaus.
* Piedmont plateaus are bordered on one side by mountains and on the other by a plain or a sea. The 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 [[Earth:Antarctic Plateau|Antarctic Plateau]] in [[Earth:East Antarctica|East Antarctica]].

== Large plateaus by continent ==
=== Africa ===
The highest African plateau is the [[Earth:Ethiopian Highlands|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 4,550 metres (14,928 ft). It is sometimes called the Roof of Africa due to its height and large area.

Another example is the [[Place:Highveld|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 largest South African [[Engineering: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 [[Earth:Antarctic Plateau|Antarctic Plateau]], which is sometimes referred to as the Polar Plateau or King Haakon VII Plateau, home to the geographic [[Earth:South Pole|South Pole]] and the Amundsen–Scott South Pole Station, which covers most of [[Earth:East Antarctica|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 [[Earth:Glacier|glacier]]s. The [[Earth:Polar ice cap|polar ice cap]] is so massive that the echolocation measurements of ice thickness have shown that large areas are below [[Sea level|sea level]]. But, as the ice melts, the land beneath will [[Earth:Post-glacial rebound|rebound]] through [[Earth:Isostasy|isostasy]] and ultimately rise above sea level.{{Citation needed|date=June 2020}}

=== Asia ===
The largest and highest plateau in the world is the [[Place:Tibetan Plateau|Tibetan Plateau]], sometimes metaphorically described as the "Roof of the World", which is still being formed by the collisions of the [[Earth:Indo-Australian Plate|Indo-Australian]] and [[Earth:Eurasian Plate|Eurasian]] [[Earth: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 [[Earth:Hadley cell|Hadley cell]] convection cycles and to drive the [[Earth:Monsoon|monsoon]]s of India towards the south. The 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: [[Place:Najd|Najd]] on the [[Place:Arabian Peninsula|Arabian Peninsula]], elevation 762 to 1,525 m (2,500 to 5,003 ft), [[Earth:Armenian Highlands|Armenian Highlands]] (≈{{Convert|400000|km2|abbr=on}}, elevation {{convert|900-2100|m|ft}}), [[Place:Iranian Plateau|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 [[Earth:Colorado Plateau|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 bisected by the [[Earth:Colorado River|Colorado River]] and the [[Earth:Grand Canyon|Grand Canyon]]. This came to be over 10 million years ago, a 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|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 [[Earth:Australian Shield|Australian Shield]], is an ancient [[Earth:Craton|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 [[Earth:North Island Volcanic Plateau|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, [[Earth:Lake Taupō|Lake Taupo]]. 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.

=== South America ===
{{Further|Earth:Tepui}}

A '''tepui''' ({{IPAc-en|pron|ˈ|t|ɛ|p|w|i}}), or '''tepuy''' ({{IPA-es|teˈpuj|lang}}), is a [[Earth:Table (landform)|table-top mountain]] or [[Earth:Mesa|mesa]] found in the Guiana Highlands of South America, especially in Venezuela and western Guyana. The word tepui means "house of the gods" in the native tongue of the Pemon, the Indigenous people who inhabit the Gran Sabana.

Tepuis can be considered minute plateaus and tend to be found as isolated entities rather than in connected ranges, which makes them the host of a unique array of endemic plant and animal species. Some of the most outstanding tepuis are Neblina, Autana, Auyan and Mount Roraima. They are typically composed of sheer blocks of [[Earth:Precambrian|Precambrian]] [[Earth:Quartz arenite|quartz arenite]] [[Earth:Sandstone|sandstone]] that rise abruptly from the jungle, giving rise to spectacular natural scenery. Auyán-tepui is the source of Angel Falls, the world's tallest [[Earth:Waterfall|waterfall]].

The Colombian capital city of Bogota sits on an 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.

[[File:The Road to the Stars.jpg|thumb|Road to the [[Astronomy:Atacama Large Millimeter Array|ALMA]]'s Operations Support Facility and then on further to the 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 [[Earth:Lake Titicaca|Lake Titicaca]], the largest lake in South America.

== See also ==
* {{annotated link|Earth:Butte}}
* {{annotated link|Earth:Chapada}}
* {{annotated link|Earth:Mesa}}
* {{annotated link|Earth:Oceanic plateau}}
* {{annotated link|Earth:Potrero (landform)|Potrero}}
* {{annotated link|Earth: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=[[Company:Routledge|Routledge]] |date=2011 |isbn=978-0-203-86008-3}}

== External links ==
{{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}}

[[Category:Plateaus| ]]
[[Category:Slope landforms]]

{{Sourceattribution|Plateau}}