In many parts of the world, volcanoes rise like towers above the land, sitting quietly for hundreds, even thousands, of years. Many appear to be no more than snow-capped mountains, which vacationers and locals use for hiking, skiing, and other outdoor...

vent in the crust of the Earth or other planet or satellite, from which issue eruptions of molten rock, hot rock fragments, and hot gases. A volcanic eruption is an awesome display of the Earth's power. Yet while eruptions are spectacular to watch,...

Volcanoes are vents or fissures in Earth's crust through which lava, gases, and pyroclastic debris are released. More commonly, the term volcano refers to the landform built up from the accumulation of lava and/or pyroclastic debris. Based on...

A volcanic eruption is the release of molten rock and volcanic gases through Earth's crust to the surface. Molten rock within the earth, or magma, is driven to erupt by buoyancy because it is lighter than the surrounding rock. Dissolved gases...

Volcanoes have been called the thermostat of the planet. They wreak havoc, but also spawn far-ranging benefits for soil and air. Some earth scientists now say that the vast swath of destruction from a volcanic eruption can be a source of creation....

Of the more than 1,500 potentially active volcanoes in the world, eight to ten are erupting at any given moment. On the bottom of the seabed circling the Pacific basin lies a series of volcanic arcs and oceanic trenches coinciding with the edges of one...

any of various processes and phenomena associated with the surficial discharge of molten rock, pyroclastic fragments, or hot water and steam, including volcanoes, geysers, and fumaroles. Although volcanism is best known on Earth, there is evidence that...

Volcanic vents are openings in Earth's crust where molten lava and volcanic gases escape onto the land surface or into the atmosphere. Most volcanoes have a circular central vent near their summit crater that serves as a conduit for ongoing...

Vent in the crust of the Earth from which molten rock, hot rock fragments, ash, gas, and steam issue. Most volcanoes are found on the boundaries of the enormous plates that make up the Earth's surface. Some of the most violent eruptions take place...

Any of various processes and phenomena associated with the surface discharge of molten rock or hot water and steam, including volcanoes, geysers, and fumaroles. Most active volcanoes occur where two plates converge and one overrides the other (&see;...

See Geomorphology and...

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