Related topics: volcano

'Limnic eruption': DR Congo's volcano nightmare

Orders on Thursday to evacuate Goma, a city lying in the shadow of DR Congo's Mount Nyiragongo volcano, have shed light on a rare but potentially catastrophic risk—a "limnic eruption," when volcanic activity combined with ...

'Huge' explosion rocks St. Vincent as volcano keeps erupting

La Soufriere volcano fired an enormous amount of ash and hot gas early Monday in the biggest explosive eruption yet since volcanic activity began on the eastern Caribbean island of St. Vincent late last week, with officials ...

Satellites monitor Mount Etna's unpredictable behavior

Italy's Mount Etna, Europe's most active volcano, has recently been on explosive form, with 17 eruptions in less than three months. Instruments onboard three different satellites orbiting Earth have acquired imagery of the ...

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Volcano

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time. The word volcano is derived from the name of Vulcano island off Sicily. In turn, it was named after Vulcan, the Roman god of fire.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example 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. Volcanoes can also form where there is stretching and thinning of the Earth's crust (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

Volcanoes can be caused by mantle plumes. These so-called hotspots, for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.

This text uses material from Wikipedia, licensed under CC BY-SA