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

Volcanoes are classified as active, dormant, or extinct. Agile volcanoes accept a recent history of eruptions; they are likely to erupt again. Fallow volcanoes have not erupted for a very long time just may erupt at a future time. Extinct volcanoes are not expected to erupt in the futurity.

Inside an active volcano is a chamber in which molten stone, called magma, collects. Pressure builds upwards inside the magma chamber, causing the magma to movement through channels in the rock and escape onto the planet's surface. Once information technology flows onto the surface the magma is known as lava.

Some volcanic eruptions are explosive, while others occur equally a tedious 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 equally the composition of the magma, make up one's mind the shape of the volcano.

Volcanoes are found on both land and the ocean floor. When volcanoes erupt on the sea 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 become so big they ascent 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.

agile volcano

Noun

volcano that has had a recorded eruption since the last glacial menstruum, almost 10,000 years ago.

dormant volcano

Substantive

volcano that has erupted in the past but is unlikely to erupt soon.

erupt

Verb

to explode or suddenly eject fabric.

lava

Noun

molten stone, or magma, that erupts from volcanoes or fissures in the Earth'due south surface.

Noun

molten, or partially melted, stone below the World's surface.

molten

Describing word

solid material turned to liquid by heat.

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    Director

    Tyson Brown, National Geographic Society

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    National Geographic Guild

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

    Last Updated

    April 5, 2019

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