Volcanism - Volcanism Volcanism is any eruption of molten...

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Volcanism Volcanism is any eruption of molten lava onto the surface. The molten rock has a lower density than solid rock so it rises. Also the pressure from the surrounding solid rock squeezes the molten rock upward. Molten rock contains trapped gases that expand as it rises causing it to rise even faster. The structures that result from erupting lava depend on the thickness and density of the lava. Very thick, low-density lava can make steep-sided stratovolcanoes like the Cascade volcanoes in Oregon and Washington and Mt Fuji in Japan . The lava does not flow as far as the other two types, so their diameters are not as great as the other types. They are common on the Earth. The "pancake domes" on Venus may be considered a type of stratovolcano but their shapes are much more cylindrical without a peak. Mt Shasta is near the southern end of the Cascade Range of volcanoes. If the lava is made of thinner, higher density material called basalt , the volcanoes will be much wider in diameter. Thicker basalt will make
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

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Volcanism - Volcanism Volcanism is any eruption of molten...

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