A volcano is an opening in a planet or moon'south chaff through which molten stone, hot gases, and other materials erupt. Volcanoes often form a hill or mountain as layers of rock and ash build up from repeated eruptions.

Volcanoes are classified as active, dormant, or extinct. Active volcanoes accept a recent history of eruptions; they are probable to erupt once again. Dormant volcanoes have not erupted for a very long time merely may erupt at a future time. Extinct volcanoes are not expected to erupt in the hereafter.

Inside an active volcano is a chamber in which molten rock, called magma, collects. Pressure builds upwardly inside the magma bedchamber, causing the magma to motility through channels in the rock and escape onto the planet'south surface. Once it flows onto the surface the magma is known as lava.

Some volcanic eruptions are explosive, while others occur as a slow lava flow. Eruptions can occur through a main opening at the top of the volcano or through vents that form on the sides. The rate and intensity of eruptions, as well every bit the composition of the magma, make up one's mind the shape of the volcano.

Volcanoes are found on both land and the ocean flooring. When volcanoes erupt on the ocean flooring, they often create underwater mountains and mount ranges as the released lava cools and hardens. Volcanoes on the sea floor become islands when the mountains get and then large they rise above the surface of the ocean.

Volcanoes

Volcanic eruptions can create colorful and dramatic displays, such as this eruption of this volcano in the Virunga Moutains of the Democratic republic of the congo.

active volcano

Substantive

volcano that has had a recorded eruption since the final glacial menstruum, nearly ten,000 years ago.

dormant volcano

Substantive

volcano that has erupted in the by just is unlikely to erupt soon.

erupt

Verb

to explode or of a sudden squirt material.

lava

Noun

molten rock, or magma, that erupts from volcanoes or fissures in the Earth's surface.

Noun

molten, or partially melted, stone beneath the Earth's surface.

molten

Describing word

solid material turned to liquid past heat.

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    Tyson Brown, National Geographic Society

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    National Geographic Lodge

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    Gina Borgia, National Geographic Lodge
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    Sarah Appleton, National Geographic Gild
    Margot Willis, National Geographic Society

    Last Updated

    April 5, 2019

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