Volcano

Mt. St. Helens is an example of a stratovolcano.

Source: USGS
Used with permission

Volcanoes are emissions of magma, rock fragments, and gases from through openings in the surface of the earth. The may take the shape of a conical mountain or horizontal layers of lava flows. (See also: shield volcano, cinder cone, stratovolcano, lava flow, flood basalt)

Suggested Web Sites:

• Volcano World - extensive information about volcanoes