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In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. These areas can form in the middle of continents but eventually form ocean basins. Divergent boundaries within continents initially produce rifts which produce rift valleys. If the rifting process stops, a failed rift results. Therefore, most active divergent plate boundaries exist between oceanic plates and are often called oceanic rifts. Divergent boundaries are a type of stress called tension. Image File history File links This is a lossless scalable vector image. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... Global earthquake epicentres, 1963–1998 The 14 major plates plus the Scotia Plate Plate tectonics map from NASA This is a list of tectonic plates on Earth. ... Animated, colour-coded map showing the various continents. ... It has been suggested that this article or section be merged with Rift valley. ... African Rift Valley. ... Age of oceanic crust Oceanic crust is the part of Earths lithosphere that surfaces in the ocean basins. ...

Although still an area of active research, it appears that due to complex convection within the Earth's mantle material rises to the base of the lithosphere beneath the divergent plate boundary.^[1] This supplies the area with vast amounts of heat and a reduction in pressure that melts rock from the asthenosphere (or upper mantle) beneath the rift area forming large flood basalt or lava flows. Each eruption occurs in only a part of the plate boundary at any one time, but when it does occur, it fills in the opening gap as the two opposing plates move away from each other. The average rate of movement is comparable to how fast human fingernails grow, about 2 cm a year.^{[citation needed]} Convection in the most general terms refers to the movement of currents within fluids (i. ... This article is about Earth as a planet. ... Earth cutaway from core to exosphere. ... The tectonic plates of the lithosphere on Earth. ... This article is about the geological substance. ... This article does not cite any references or sources. ... Moses Coulee showing multiple flood basalt flows of the Columbia River Basalt Group. ... This article discusses the anatomical nail. ...

Over millions of years, the plates have moved many hundreds of kilometers away from both sides of the divergent plate boundary. Because of this, rock closest to the boundary is younger than rock further away on the same plate.

Divergent boundaries

• The Mid-Atlantic Ridge
• The boundary between the African Plate and Arabian Plate (the Red Sea)
• Great Rift Valley
• West Antarctic Rift
• East Pacific Rise
• Pacific-Antarctic Ridge
• Galapagos Rise
• Gakkel Ridge

Courtesy USGS The ridge was central in the breakup of Pangaea that began some 180 million years ago. ...  The African plate, shown in pinkish-orange The African Plate is a tectonic plate covering the continent of Africa and extending westward to the Mid-Atlantic Ridge. ... The Arabian plate is shown in bright yellow on this map The Arabian Plate is a continental tectonic plate covering the Arabian peninsula and extending northward to Turkey. ... Location of the Red Sea The Red Sea is an inlet of the Indian Ocean between Africa and Asia. ... Northern section of the Great Rift Valley. ... The West Antarctic Rift is a major, active rift valley lying between East and West Antarctica. ... The East Pacific Rise is a long north-south welt of seafloor spreading under the eastern Pacific Ocean from near Antarctica in the south northward to its termination at the northern end of the Gulf of California in the Salton Sea basin in southern Pennsylvania California. ... The Pacific-Antarctic Ridge is the southern extension of the East Pacific Rise The Pacific-Antarctic Ridge is an oceanic ridge at the boundary between the Pacific and Antarctic Plates. ... The Galapagos Rise is a divergent boundary located near the triple junction of the Nazca Plate, the Cocos Plate, and the South American Plate. ... The Gakkel Ridge is a mid-oceanic ridge located in the Arctic Ocean between Greenland and Siberia with a length of about 1800 kilometers. ...

Other plate boundary types

• Convergent boundary
• Transform boundary

In plate tectonics, a convergent boundary – also known as a convergent plate boundary or a destructive plate boundary – is an actively deforming region where two (or more) tectonic plates or fragments of lithosphere move toward one another. ... In plate tectonics, a transform boundary (also known as transform fault boundary, transform plate boundary, transform plate margin, strike-slip boundary, sliding boundary, or conservative plate boundary) is said to occur when tectonic plates slide and grind against each other along a transform fault. ...

See also

• Seafloor spreading
• Plate tectonics
• Continental drift
• Subduction zone

Age of oceanic crust. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... Plates in the crust of the earth, according to the plate tectonics theory Continental drift refers to the movement of the Earths continents relative to each other. ... Categories: Geology stubs | Plate tectonics ...

References