In plate tectonics, the study of volcanoes is a fascinating one. Some plate tectonics students
only study volcanoes. The Earth is made of three sections, the crust, the mantle and the core. The crust is
very thin and cool compared to other parts of the Earth. Underneath the Earth's crust is the mantle made of very
hot soft rock. The soft rock is called magma. Sometimes the hot magma breaks through a thin weal part of the crust
forming a volcano.
Some volcanoes are not active and stay dormant doing nothing for hundreds of years. But hot
magma can shoot out of the crater suddenly. This is called erupting. When a volcano erupts, the hot magma flows out
of the Earth's crust, down the sides of the volcano and becomes hard as it cools. Hot magma flowing out of the
crust is called lava. The hole of the Earth's crust where the magma broke the surface is called a crater. Some of
the lava contain bubbles of gas and form pumice when cooled.
Picture of a volcano erupting