Volcano
hideA volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time. The word volcano is derived from the name of Vulcano island off Sicily. In turn, it was named after Vulcan, the Roman god of fire.
Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.
Volcanoes can be caused by mantle plumes. These so-called hotspots, for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.
For more information about Volcano, read the full article at
Wikipedia.
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News tagged with volcanic eruptions
Rich Ore Deposits Linked to Ancient Atmosphere
Space & Earth / Earth Sciences
Nov 19, 2009 |
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(PhysOrg.com) -- Much of our planet's mineral wealth was deposited billions of years ago when Earth's chemical cycles were different from today's. Using geochemical clues from rocks nearly 3 billion years old, a group of ...
Volcanic eruptions may split Africa: scientists
Space & Earth / Earth Sciences
Nov 03, 2009 |
4.8 / 5 (8) |
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Volcanic activity may split the African continent in two owing to a recent geological crack in northeastern Ethiopia, researchers said on Tuesday.
Giant impact near India -- not Mexico -- may have doomed dinosaurs
Space & Earth / Earth Sciences
Oct 15, 2009 |
4.8 / 5 (42) |
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A mysterious basin off the coast of India could be the largest, multi-ringed impact crater the world has ever seen. And if a new study is right, it may have been responsible for killing the dinosaurs off 65 ...
Study compares sound from exploding volcanoes with jet engines
Space & Earth / Earth Sciences
Apr 08, 2009 |
3.8 / 5 (5) |
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New research on infrasound from volcanic eruptions shows an unexpected connection with jet engines. Researchers at Scripps Institution of Oceanography at UC San Diego speeded up the recorded sounds from two ...
Scientists offer new theory for largest known mass extinction
Space & Earth / Earth Sciences
Mar 30, 2009 |
4 / 5 (21) |
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The largest mass extinction in the history of the earth could have been triggered off by giant salt lakes, whose emissions of halogenated gases changed the atmospheric composition so dramatically that vegetation ...
Atmospheric 'sunshade' could reduce solar power generation
Mar 11, 2009 |
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The concept of delaying global warming by adding particles into the upper atmosphere to cool the climate could unintentionally reduce peak electricity generated by large solar power plants by as much as one-fifth, ...
