Guyot

:"For the French viticulturist, see Jules Guyot. For the Old French name, see Guiot."A guyot, also known as a tablemount, is a flat-topped seamount. Guyots are most commonly found in the Pacific Ocean. Guyots show evidence of having been above the surface with gradual subsidence through stages from fringed reefed mountain, coral atoll, and finally a flat topped submerged mountain. Their flatness is due to erosion by waves, winds, and atmospheric processes. The surfaces of some of the largest guyots measure 10 km (6 mi). [ [http://www.britannica.com/eb/article-9038617/guyot guyot - Britannica Online Encyclopedia ] ] The steepness gradient of most guyots is about 20 degrees. To technically be considered a guyot or tablemount, they must stand at least 3000 ft (900 m) tall. However, there are many undersea mounts that can range from just less than 3000 ft to around 300 ft. Very large oceanic volcanic constructions, hundreds of kilometers across, are called oceanic plateaus. [ [http://www.answers.com/topic/seamount-and-guyot?cat=technology Seamount and guyot: Information and Much More from Answers.com ] ] Seamounts are made by extrusion of lavas piped upward in stages from sources within the Earth's mantle to vents on the seafloor. Seamounts provide data on movements of tectonic plates on which they ride, and on the rheology of the underlying lithosphere. The trend of a seamount chain traces the direction of motion of the lithospheric plate over a more or less fixed heat source in the underlying asthenosphere part of the Earth's mantle. [Seamounts are made by extrusion of lavas piped upward in stages from sources within the Earth's mantle to vents on the seafloor. Seamounts provide data on movements of tectonic plates on which they ride, and on the rheology of the underlying lithosphere. The trend of a seamount chain traces the direction of motion of the lithospheric plate over a more or less fixed heat source in the underlying asthenosphere part of the Earth's mantle.] There are thought to be an estimated 50,000 seamounts in the Pacific basin. The Emperor Seamounts are an excellent example of an entire volcanic chain undergoing this process and contain many guyots among their other examples.

We know that underwater guyots were originally above water due to the extensive amount of fossils discovered on the top of guyots. Another factor contributing to the guyots being underwater has to do with the oceanic ridges, such as the Mid-Atlantic Ridge in the Atlantic Ocean. Mid-ocean ridges gradually spread apart overtime, due to molten lava being pushed up under the surface of the earth and creating new rock. As the mid-ocean ridges spread apart, the guyots move with them, thus continually sinking deeper into the depths of the ocean. Thus, the greater amount of time that passes, the deeper the guyots become. [ [http://www.utdallas.edu/~pujana/oceans/guyot.html Guyot ] ] Although guyots can be hundreds of millions of years old, there have been some recently discovered guyots that were only formed within the last 1 million years.

One guyot in particular, the Great Meteor Tablemount in the Northeast Atlantic Ocean, stands at more than 4,000 m (13,120 ft). The guyot's diameter is 110 km (70 mi). [ [http://www.britannica.com/eb/topic-243463/Great-Meteor-Tablemount Great Meteor Tablemount (volcanic mountain, Atlantic Ocean) - Britannica Online Encyclopedia ] ] Guyots are also associated with specific lifeforms and varying amounts of organic matter. Local increases in chlorophyll a, enhanced carbon incorporation rates and changes in phytoplankton species composition were associated with the seamount. [ [http://www.sahfos.ac.uk/bibliography_M.htm ||Sahfos|| ] ]

Guyots were first seen by Harry Hammond Hess in 1945 who collected data using echo-sounding equipment on a ship he commanded during World War II.Fact|date=October 2007 The data showed the configuration of the seafloor where he saw that some undersea mountains had flat tops. The geology building at Princeton University is, and was, called Guyot Hall (being named after the 19th century geographer Arnold Henry Guyot [http://etcweb.princeton.edu/CampusWWW/Companion/guyot_arnold.html Guyot, Arnold in "A Princeton Companion"] . Guyot Hall has a flat roof, so Hess called these undersea mountains guyots (because they resembled Guyot Hall). Hess postulated they were once volcanic islands that were beheaded by wave action yet they are now deep under sea level. This idea was used to help bolster the theory of plate tectonics.Fact|date=October 2007

More recently, seamounts have been used as an international effort to protect marine ecosystems.Fact|date=May 2008

ee also

*Hawaiian-Emperor seamount chain
*New England Seamount chain
*Kodiak-Bowie Seamount chain
*Evolution of Hawaiian volcanoes
*Hotspot (geology)
*Atoll
*Seamount

References

External links

* [http://oceanworld.tamu.edu/resources/ocng_textbook/chapter03/chapter03_03.htm Wilde guyot map from Texas A&M]


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Look at other dictionaries:

  • guyot — guyot …   Dictionnaire des rimes

  • guyot — s.n. (geol.) Relief submarin de origine vulcanică, în formă de trunchi de con cu secţiune ovală, care se ridică izolat pe fundul oceanului. [< fr., engl. guyot, cf. Guyot – geolog american]. Trimis de LauraGellner, 20.04.2005. Sursa: DN … …   Dicționar Român

  • Guyot —   [gɥi jo; nach dem schweizerisch amerikanischen Geologen Arnold Henry Guyot, * 1807, ✝ 1884], untermeerische Kuppe vulkanischer Entstehung, mit ebenem Gipfelplateau, z. B. die Große Meteorbank.   * * * Gu|yot [gy̆i jo:], der; s, s [nach dem… …   Universal-Lexikon

  • guyot — flat topped submarine mountain, 1946, named for Swiss geographer/geologist Arnold Guyot (1807 1884) …   Etymology dictionary

  • guyot — ☆ guyot [gē′ō΄, gē ō′ ] n. [after A. H. Guyot (1807 84), U.S. geologist] a flat topped, steeply rising seamount; tablemount …   English World dictionary

  • Guyot — Guyot, Heinrich Daniel, geb. 1753 in Trois Fontaines bei Mastricht, wurde 1776 Pfarrer in Dordrecht u. 1781 in Gröningen, erhielt hier 1801 auch die Inspection der Schulen. Schon 1790 gründete er eine Taubstummenanstalt u. legte 1809 sein… …   Pierer's Universal-Lexikon

  • Guyot — (spr. gijo), 1) Arnold Henry, Geograph und Physiker, geb. 28. Sept. 1807 in Neuchâtel (Schweiz), gest. 30. Jan. 1884 in Princeton (New Jersey), studierte seit 1833 zu Berlin Theologie, daneben Naturwissenschaft, lebte seit 1835 in Paris und auf… …   Meyers Großes Konversations-Lexikon

  • Guyot — (spr. gijoh), Yves, franz. Politiker, geb. 6. Sept. 1843 zu Dinan, Journalist, 1885 radikaler Deputierter, 1889 92 Minister der öffentlichen Arbeiten; schrieb: »Études sur les doctrines sociales du christianisme« (2. Aufl. 1881; deutsch 1893),… …   Kleines Konversations-Lexikon

  • Guyot — Diminutif de Guy (voir ce nom) très fréquent dans toute la France. C est dans le Morbihan et la Haute Saône qu il est le plus répandu, sans compter Paris …   Noms de famille

  • Guyot — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. Sommaire 1 Géologie 2 Fruit 3 Patronymes …   Wikipédia en Français

  • guyot — 1. guyot [ gɥijo ] n. m. • 1956; du n. pr. Arnold Guyot ♦ Océanogr. Volcan sous marin, de forme conique à sommet aplati, de 3 à 4 000 m de hauteur. Atolls et guyots. guyot 2. guyot [ gɥijo ] n. f. • 1924; du n. pr. Jules Guyot ♦ Poire sucrée,… …   Encyclopédie Universelle

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