Academic Reading
How volcanoes form
ADeep beneath the Earth's surface, rock is so hot that it can melt into a substance called magma. Because magma is lighter than the solid rock around it, it slowly rises towards the surface, collecting in chambers underground. When the pressure becomes too great, the magma forces its way out through a weakness in the crust, and a volcano erupts.
BOnce magma reaches the surface it is called lava. Over many eruptions, layers of cooled lava and ash build up to form the cone-shaped mountains we recognise as volcanoes. Most of the world's volcanoes are found along the edges of the great plates that make up the Earth's crust.