how do volcano's erupt?
Description: My favorite volcano
Image copyright: http://www.permapak.net/volcano.htm
National Geographic 1996 2007 http://www.NationalGeographic.com/forcesofnature.
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Volcano inc.
how do volcano's erupt? Description: My favorite volcano Image copyright: http://www.permapak.net/volcano.htm |
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Eruption begins when magma, molten rock from the earths crust, rises toward the surface. Dissolved gases in the magma determine gases in the magma determine whether the eruption will be big or small. Silica determines the viscosity. Low viscosity is runny. High viscosity is thick. Pressure builds up in the magma until the gases explode creating an eruption. Tectonic plates slide together and rock is pushed toward the interior of the earth. The pressure heats it up and turns it into magma. Also eruptions can occur when large amounts of gas build up under the surface. Then, if too much gas builds up, the volcano erupts.
National Geographic 1996 2007 http://www.NationalGeographic.com/forcesofnature. |
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