Introduction on Volcano

A Volcano is a conical hill or mountain formed by material from the mantle being forced through an opening or vent in the Earth's crust. Volcanoes are found in three states - extinct, dormant and active. An extinct volcano will never erupt again. A dormant volcano has not erupted in 2000 years. An active volcano has erupted recently and is likely to erupt again. 

^Kilauea Volcano, Hawaii. It is one of the world's most active volcano. 

It last erupted in January 3 1983.

^Santa Isabel, Colombia. It is a extinct volcano. It last erupted in 1923.

There are many different types of volcanoes. There are 3 main type of volcanoes are composite, shield and cinder cone.

These volcanoes are typically tens of miles across and ten thousand or more feet in height. They have moderately steep sides and sometimes have small craters in their summits. They consist of layers of solid lava flows mixed with layers of sand- or gravel-like volcanic rock called cinders or volcanic ash.

Shield volcanoes have low slopes and consist almost entirely of frozen lavas. They almost always have large craters at their summits.This type of volcano can be hundreds of miles across and many tens of thousands of feet high.

These type of volcanoes consist almost entirely of loose, grainy cinders and almost no lava. They are small volcanoes, usually only about a mile across and up to about a thousand feet high. They have very steep sides and usually have a small crater on top.

Here is a picture of the other kind of volcano: