oceanic plateau

oceanic plateau
or submarine plateau

Large submarine elevation rising sharply at least 660 ft (200 m) above the surrounding seafloor and having an extensive, relatively flat or gently tilted summit.

Most plateaus are steplike interruptions of the continental slopes. Some, however, occur well beyond the continental margins. They stand alone, high above the surrounding seafloor, and are believed to be fragments of continents that were isolated during continental drift and seafloor spreading.

* * *

also called  Submarine Plateau,  

      large submarine elevation rising sharply at least 200 m (660 feet) above the surrounding deep-sea floor and characterized principally by an extensive, relatively flat or gently tilted summit. Most oceanic plateaus were named early in the 20th century prior to the invention of sonic sounding, and many of these features have been shown by modern bathymetric data to be portions of the oceanic ridges. Thus, the Albatross Plateau of the eastern equatorial Pacific now is recognized as belonging to the East Pacific Rise and has been shown to possess a much more irregular summit than early data indicated.

      Most plateaus are steplike interruptions of the continental slopes and appear to be downwarped or downfaulted blocks of former continental shelves. These marginal plateaus are exemplified by the Blake Plateau off the southeastern United States. This plateau's flat surface lies between 700 and 1,000 m (2,300 and 3,300 feet) below sea level, is more than 300 km (185 miles) wide, and covers approximately 130,000 square km (50,000 square miles) of seafloor. The crust underlying the plateau, although relatively thin and veneered by flat-lying marine sediments, is otherwise continental in character.

      Other plateaus, such as the coral-capped plateaus of the South China Sea, occur in the ocean well beyond the continental margins. They stand above the surrounding deep-sea floor as isolated topographic highs and are believed to be composed of continental rock cores overlain by flat-lying marine sediments. Presumably, these mid-ocean plateaus are minor fragments of continent that have been isolated during continental drift and seafloor spreading.

* * *


Universalium. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Oceanic plateau — An oceanic plateau (also submarine plateau) is a large, relatively flat submarine region that rises well above the level of the ambient seabed.[1] While many oceanic plateaus are composed of continental crust, and often form a step interrupting… …   Wikipedia

  • Oceanic trench — Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric scale long but narrow topographic depressions of the sea floor. They are also the… …   Wikipedia

  • Plateau (disambiguation) — Plateau has several meanings:*In geology or earth science, a plateau is an area of relative low relief (i.e., relatively flat) at an important altitude, usually attributed to tectonic uplift or by sediment accumulation. If the uplift was recent,… …   Wikipedia

  • Oceanic crust — Age of oceanic crust. The red is most recent, and blue is the oldest. Oceanic crust is the part of Earth s lithosphere that surfaces in the ocean basins. Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and… …   Wikipedia

  • Oceanic basin — Diagrammatic cross section of an ocean basin, showing the various geographic features Hydrologically, an oceanic basin may be anywhere on Earth that is covered by seawater, but geologically ocean basins are large geologic basins that are below… …   Wikipedia

  • Oceanic zone — Marine habitats The oceanic zone is the deep open ocean water that lies off the continental slopes Littoral zone Intertidal zone …   Wikipedia

  • oceanic — /oh shee an ik/, adj. 1. of, living in, or produced by the ocean: oceanic currents. 2. of or pertaining to the region of water lying above the bathyal, abyssal, and hadal zones of the sea bottom. Cf. neritic, pelagic. 3. immensely large; vast: an …   Universalium

  • Plateau — For other meanings, see Plateau (disambiguation). Island in the Sky, Canyonlands National Park …   Wikipedia

  • plateau — /pla toh / or, esp. Brit., /plat oh/, n., pl. plateaus, plateaux / tohz , tohz/, v., plateaued, plateauing. n. 1. a land area having a relatively level surface considerably raised above adjoining land on at least one side, and often cut by deep… …   Universalium

  • Ontong Java Plateau — The Ontong Java Plateau is a huge oceanic plateau located in the Pacific Ocean, lying north of the Solomon Islands. The plateau covers an area of approximately 2,000,000 km2 (770,000 sq mi), or roughly the size of Alaska, and reaches a… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”