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Volcano

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A 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.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with volcano

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Scientists say magma building up in Mayon volcano (AP)

Scientists say magma building up in Mayon volcano

Space & Earth / Earth Sciences

created Dec 26, 2009 | popularity 4.5 / 5 (10) | comments 0

(AP) -- Fewer earthquakes have been recorded in the Philippines' lava-spilling Mayon volcano, but magma continues to build up inside and any lull in activity could be followed by a bigger eruption, scientists ...


ROV Jason images the discovery of the deepest explosive eruption on the sea floor (w/ Video)

Oceanographers image the discovery of the deepest explosive eruption on the sea floor (w/ Video)

Space & Earth / Earth Sciences

created Dec 17, 2009 | popularity 4.9 / 5 (9) | comments 1

Oceanographers using the remotely operated vehicle (ROV) Jason discovered and recorded the first video and still images of a deep-sea volcano actively erupting molten lava on the seafloor.


Philippine volcano gets louder, could blow up soon (AP)

Philippine volcano gets louder, could erupt soon

Space & Earth / Earth Sciences

created Dec 21, 2009 | popularity 5 / 5 (6) | comments 0

(AP) -- Philippine troops on Monday pressed the last 3,000 villagers who have refused to heed government warnings to leave the danger zone around a volcano that experts say is ready to erupt.


Major volcanic eruption feared in Philippines (AP)

Major volcanic eruption feared in Philippines

Space & Earth / Earth Sciences

created Dec 20, 2009 | popularity 4.7 / 5 (6) | comments 0

(AP) -- The Philippines' most active volcano could have a huge eruption within days, officials warned Sunday after detecting a drastic surge in earthquakes and eerie rumbling sounds in surrounding foothills. ...


Philippine volcano rumbles with fresh explosions (AP)

Philippine volcano rumbles with fresh explosions

Space & Earth / Earth Sciences

created Dec 16, 2009 | popularity 4.8 / 5 (5) | comments 0

(AP) -- The Mayon volcano, which has blown its top nearly 40 times in 400 years, menaced nearby residents with small eruptions of ash and lava Wednesday as Philippine authorities moved more than 30,000 people ...


Ancient Pacific islanders brought to light

Ancient Pacific islanders brought to light

Other Sciences / Archaeology & Fossils

created Dec 21, 2009 | popularity 4.6 / 5 (5) | comments 0

(PhysOrg.com) -- A find of 60 headless skeletons summer 2009 may reveal the identity of the people who first inhabited the Pacific Ocean archipelago Vanuatu 3000 years ago.


Most of 47,000 Filipinos safe from raging volcano (AP)

Most of 47,000 Filipinos safe from raging volcano

Space & Earth / Earth Sciences

created Dec 22, 2009 | popularity 4.7 / 5 (3) | comments 0

(AP) -- Almost all of the 47,000 residents living on the slopes of a rumbling volcano in the central Philippines have moved to emergency shelters, and lava and earthquakes Tuesday heralded what officials ...


Merapi volcano

Pre-eruption earthquakes offer clues to volcano forecasters

Space & Earth / Earth Sciences

created Dec 16, 2009 | popularity 4.7 / 5 (3) | comments 1

Like an angry dog, a volcano growls before it bites, shaking the ground and getting "noisy" before erupting. This activity gives scientists an opportunity to study the tumult beneath a volcano and may help ...


Volcanic Quakes Help Forecast Eruptions

Volcanic Quakes Help Forecast Eruptions

Space & Earth / Earth Sciences

created Dec 22, 2009 | popularity 2.6 / 5 (5) | comments 2

Monitoring the earthquakes caused from magma movements inside an active volcano could help to improve the accuracy of forecasting an eruption.


More Filipinos leave homes as volcano spills lava (AP)

More Filipinos leave homes as volcano spills lava

Space & Earth / Earth Sciences

created Dec 18, 2009 | popularity 5 / 5 (1) | comments 0

(AP) -- Security forces in army trucks Friday sent about 3,000 residents outside the danger zone surrounding the smoldering Mayon volcano, which looked set for a major eruption after days of shooting ash ...