volcano

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How volcanoes work, explained by a volcanologist

What it's like to visit an active volcano

Classify volcanic eruptions according to the physical and chemical properties of their magma

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Arenal Volcano in northwestern Costa Rica in the province of Alajuela.

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animated gif/infographic of the Mount Tambora eruption, April 1815. volcano. Indonesia.

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Ash cloud rising from the Kilauea Volcano Pu`u `O `o as crater floor collapses due to magma withdrawal. Incandescent rubble can be seen crumbling and rolling down the scarp. East rim of Pu`u `O `o is in the foreground, Kilauea, Hawaii on March 6, 2011.

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Mount Saint Helens (Cascade Range, southwestern Washington) spewing ash during the 1980 eruption.; Mount St. Helens

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Washington DC.,USA, April 26, 1989. Supporters for and against legal abortion face off during a protest outside the United States Supreme Court Building during Webster V Health Services

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African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.

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Young boys working in a thread spinning mill in Macon, Georgia, 1909. Boys are so small they have to climb onto the spinning frame to reach and fix broken threads and put back empty bobbins. Child labor. Industrial revolution

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Queen Elizabeth II addresses at opening of Parliament. (Date unknown on photo, but may be 1958, the first time the opening of Parliament was filmed.)

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Geography & Travel

volcano

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Written by Robert W. Decker, Barbara B. DeckerSee All

Fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Apr 13, 2024 • Article History

Mount St. Helens volcano

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Category: Geography & Travel

Key People:: Sir William Hamilton; Arthur L. Day; Walter Herman Bucher

Related Topics:: hot spring; mud volcano; fumarole; submarine volcano; crater row

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volcano, vent in the crust of Earth or another planet or satellite, from which issue eruptions of molten rock, hot rock fragments, and hot gases. A volcanic eruption is an awesome display of Earth’s power. Yet, while eruptions are spectacular to watch, they can cause disastrous loss of life and property, especially in densely populated regions of the world. Sometimes beginning with an accumulation of gas-rich magma (molten underground rock) in reservoirs near Earth’s surface, they can be preceded by emissions of steam and gas from small vents in the ground. Swarms of small earthquakes, which may be caused by ...(100 of 12070 words)

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