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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

Fissure
Diagram of a volcano

Fissure
On volcanoes, a fissure is an elongated fracture or crack at the surface from which lava erupts. Fissure eruptions typically dwindle to a central vent after a period of hours or days. Occasionally, lava will flow back into the ground by pouring into a crack or an open eruptive fissure, a process called drainback; sometimes lava will flow back into the same fissure from which it erupted.

Left: A close-up of a crack in the volcanic surface of a cooled lava flow from the crater of Mt. St. Helens.

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