Have you ever seen a volcano? When looking at one, you feel amazingly insignificant! You think of the awesome power that they hold within them, and it causes a fearful respect!
How do volcanoes start?
Scientist think that volcanoes begin as an underground bubble of lava. This magma or melted rock is lighter than solid rock it wants to rise toward the earth's surface. If there is a crack or weak spot in the crust, it will find its way through and form a large chamber or reservoir called a magma chamber just below the earth's surface.
The magma begins to melt nearby rock and this increases the pressure in the chamber. This begins to push against the surrounding rock and causes it to split apart. The magma is then forced through this split and out the vent or opening. As it begins to spew, the cooling magma begins to form a rock. Yet the molten rock or magma still continues to spew forth. It keeps cooling and spewing until a new mountain is formed!
Volcanoes tend to occur in specific areas that lie between the boundaries of the plates. There is a lot of volcano activity in one area which is called the ring of fire. This is the edge of the Pacific plate.