A type of lava that forms thick, rough crust.

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A volcano that has erupted in the past 10,000 years, may be currently erupting, and is expected to erupt again. 

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Caldera

a large, cauldron-shaped depression caused by the collapse of the ground when the magma chamber is empty.

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the most common and the smallest type of volcano, usually not more than 300 m (1000ft) tall, produced by pyroclastic flows.

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also known as the stratovolcano, formed by a combonation of lava flows and pyroclastic explosions that form alternating layers. Composite volcanoes are steep and often very tall.

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an indentation at the top of a volcano

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a volcano that is not currently erupting, but is expected to erupt again.

A volcano that is sleeping

A volcano that has not erupted in the past 10,000 years and is not expected to erupt again.

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Volcanically active places that lie above mantle plumes

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magma that reaches the Earth's surface

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molten rock beneath the Earth's surface

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a large area deep undergroud filled with magma.

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a column of hot rock that rises to the surface from the Earth's interior

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a type of lava that forms a thin, ropy crust when it hardens

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a smooth, rounded type of lava that erupts underwater

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a high-temperature mixture ofhot ash and fragments of lava that erupts with great force and speed. Pyroclastic flows are the most dangerous type of volcanic eruptions, traveling at speeds of up to 200km/hr (125mph) with temperatures of up to 700 degrees. (1300 degrees F)

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volcanoes that form from fluid lava that builds up slowly over time, creating a wide, gently-sloping mountian shaped like a warrior's shield.

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any material ejecting during a pyroclastic explosion

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an opening at the top or side of a volcano where lava erupts

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very small fragments of material that are ejected in a pyroclastic explosion.

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a mass of molten lava that is ejected during a pyroclastic explosion and hardens in air. 

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