A volcano is an opening (or rupture) in the Earth's surface or crust, which allows hot, molten rock, ash, and gases to escape from deep below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.
2007-01-16 20:28:10
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answer #1
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answered by ?only?me? 6
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What is a volcano?
A volcano is a vent or 'chimney' that connects molten rock (magma) to the Earth's surface. It includes the surrounding cone of built-up material. Magma erupting from a volcano is called lava. Gases and pieces of rock erupt from volcanoes too.
A volcano is active if it erupts lava, releases gas or shows seismic activity. It is dormant if it hasn't erupted for a long time but could again one day. An extinct volcano will never erupt again.
The explosiveness of a volcanic eruption depends on how easily magma can flow and the amount of gas trapped in it. Large amounts of water and carbon dioxide are dissolved in magma. They behave like gas in fizzy drinks. After opening the bottle the gas expands, forming bubbles that escape. This also happens when magma rises quickly through the crust - gas bubbles form and expand up to 1000 times their original size.
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Hope it helps
2007-01-16 22:52:20
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answer #2
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answered by FranzeL 2
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A volcano is an opening (or rupture) in the Earth's surface or crust, which allows hot, molten rock, ash, and gases to escape from deep below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.
Volcanoes are generally found where two to three tectonic plates pull apart or are coming together. A mid-oceanic ridge, like 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 (like the San Andreas fault). Volcanoes can also form where there is stretching of the Earth's crust and where the crust grows thin (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the European Rhine Graben with its Eifel volcanoes, and the Rio Grande Rift in North America.
Finally, volcanoes can be caused by "mantle plumes," so-called "hotspots;" these hotspots can occur far from plate boundaries, such as the Hawaiian Islands. Interestingly, hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.
You could get more information from the link below...
2007-01-17 22:13:33
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answer #3
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answered by catzpaw 6
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Volcanoes are vents or fissures in the earth's crust through which gases, molten rock, or lava, and solid fragments are discharged. Their study is called volcanology. The term volcano is commonly applied both to the vent and to the conical mountain (cone) built up around the vent by the erupted rock materials. Volcanoes are described as active, dormant, or extinct. The soil resulting from decomposition of volcanic materials is extremely fertile, and the ash itself is a good polishing and cleansing agent.
2007-01-16 20:38:36
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answer #4
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answered by jamat 1
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A volcano is an opening from the earth's surface which gives out lava.
It can also be a form in which countries get geo-thermal energy.
2007-01-16 23:23:29
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answer #5
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answered by Anonymous
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Try www.wikipedia.org and find out everything you want to know about earth farts. It'd be waaaay too long if I wrote out what I know on here.
Best of luck :c)
2007-01-16 20:34:16
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answer #6
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answered by le païen 5
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