Volcanos

Volcanoes

What is a Volcano?
A volcano is a mountain that opens downward to a pool of molten rock (magma) below the surface of the earth. It is a hole in the Earth from which molten rock and gaserupt.

Different states of Volcanoes
There are three different states of volcanoes, there found in extinct, dormant and active state. An extinct volcano will never erupt again. A dormant volcanohas not erupted in 2000 years. An active volcano has erupted recently and is likely to erupt again.

Different types of Volcanoes
There are many different types of volcanoes. The way they areformed depends on many factors like the fluidity of the lava (how runny it is) and the temperature of the lava.
Shield volcanoes have gentle slopes and are very wide. Shield volcanoes are formed when lavais very hot and very runny. They consist of many thin layers of rock. 
Composite Volcanoes are also known as strato volcanoes. They are steep sided volcanoes formed by alternating layers of lava,ash and rock fragments.  This is the reason they are called composite. Composite volcanoes are very explosive because the lava is very thick.
Cinder cones are built from lava fragments calledcinders.  The lava fragments are ejected from a single vent and accumulate around the vent when they fall back to earth. Cinder cones grow rapidly and soon approach their maximum size.  They rarely exceed250m in height and 500m in diameter.
Complex volcanoes are called that way because of the "systems" of those volcanoes are not "simple". A volcano that consists of two or more vents is reckoned asa compound or complex volcano.

World largest volcano
The largest volcano on earth is Mauna Loa on Hawaii’s Big Island. It is a massive shield volcano formed by lots of lava flows. When measured fromthe base to the top, the pile of lavas measures more than 17,000 m (56,000 ft). When measured from the sea floor, Mauna Loa's height is still more than 9,000 m, thus it is also the highest mountain...