Most people have never seen a real volcano but have learned about them through movies or books. So when most people think of a volcano, they usually conjure up the Hollywood version: a huge, menacing conical mountain that explodes and spews out masses of lava which falls on rampaging dinosaurs, screaming cave people, or fleeing mobs of betogaed Romans - depending on their favorite volcano disaster movie. While those types of volcanoes do indeed exist, they represent only one "species" in a veritable zoo of volcano shapes and sizes.
Composite Volcanoes: The most majestic of the volcanoes are composite volcanoes, also known as strato-volcanoes. Composite volcanoes are tall, symetrically shaped, with steep sides, sometimes rising 10,000 feet high. They are built of alternating layers of lava flows, volcanic ash, and cinders.
Famous composite volcanoes include Mount Fuji in Japan, Mount Shasta and Mount Lassen in California, Mount St. Helens and Mount Rainier in Washington State, Mount Hood in Oregon, and Mount Etna in Italy.
Fissure Volcano: Fissure volcanoes have no central crater at all. Instead, giant cracks open in the ground and expel vast quantities of lava. This lava spreads far and wide to form huge pools that can cover almost everything around. When these pools of lava cool and solidify, the surface remains mostly flat. Since the source cracks are usually buried, there is often nothing "volcano-like" to see - only a flat plain.
A fissure eruption occured at the Los Pilas volcano in Nicaragua in 1952.
Cinder Cones: Cinder cones are simple volcanoes which have a bowl-shaped crater at the summit and steep sides. They only grow to about a thousand feet, the size of a hill. They usually are created of eruptions from a single opening, unlike a strato-volcano or shield volcano which can erupt from many...