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Volcano's Deadly Warning

Anatomy of a Volcano

 

Intro | Ash | Lava flow | Lava dome | Lava |  Vent  | Tephra | Caldera | Lahar | Fissure | Dike | Magma

Volcano's Deadly Warning homepage

Vent
Diagram of a volcano

Vent
Vents are openings in the Earth's crust from which magma and volcanic gases escape onto the ground or into the atmosphere. Vents may consist of a single, circular-shaped structure, a large elongated fissure and fracture, or a tiny ground crack. The release of volcanic gases and the eruption of molten rock result in a wide assortment of edifices, ranging from enormous shield volcanoes and calderas to fumaroles and small hornitos.

Left: Steam rises from a vent on Mount Asahidake, a volcano on Hokkaido, Japan.

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NOVA Home Find out what's coming up on air Listing of previous NOVA Web sites NOVA's history Subscribe to the NOVA bulletin Lesson plans and more for teachers NOVA RSS feeds Tell us what you think Program transcripts Buy NOVA videos or DVDs Watch NOVA programs online Answers to frequently asked questions