VOLCANOES

Volcanoes

The eruption of a volcano
An exploding volcano throws lava, gas and ash into the air. The liquid magma, which is melted rock, starts its journey upwards through the volcano from a magma chamber, or lake, deep inside the earth.

Magma reaches the surface through the vertical main pipe of a volcano. It is forced up by pressure from deep inside the earth. When it comes out of the earth's surface it is called lava. The lava pours out of the hole or vent, at the surface of the volcano. A vent can be at the top or sides of a volcano.

Different kinds of volcano

A cone volcano is made up of layers of hardened lava and ash, built up each time the volcano erupts.

Mayon volcano in the Philippines is a cone volcano

A crater volcano is formed when a cone volcano collapses into the magma chamber, forming a caldera. When the volcano next erupts a new cone is formed, in the middle of the caldera. Sometimes, the caldera fills with water, forming a caldera lake.

Taal volcano in the Philippines is a crater volcano..............................................................................

Shield volcanoes
Another kind of volcano is a shield volcano, which is built almost entirely of fluid lava flows. Flow after flow pours out of the volcano's vent or vents in all directions, to build a broad, gently sloping cone. From the side the volcano looks like a warrior's shield, which is how it got the name.

Cross-section of a volcano

Read more about different kinds of volcano

here: http://pubs.usgs.gov/gip/volc/types.html

http://volcano.und.nodak.edu/vw.html

Acknowledge this source in your bibliography like this:
Thomas, R. & Sydenham, S. Volcanoes. [Online] www.kidcyber.com.au (2000)

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