iverson kingdom wants to know. why do volcanoes erupt. they look so peaceful until that not dozens of volcanoes erupt every year. most live at the scene where tectonic plates on land open if an ocean push against each other or move apart making the earth's crust unstable. volcanoes are the planet's way of letting off steam. the earth is made up of layers in the thick mantle around the core and beneath the fin out of crust rock melts into magma under great pressure and temperature. the magma expands and pushes up with when it breaks through the surface it's called lava. there are different kinds of all kind of corruption if a massive column shoots into the sky it's called a plenty interruption. when the magma heats up water causing an explosion of steam it's called free attic. subglacial one's a proud one lover meets ice usually under a glacier. these are just 3 examples there are several more categories. conical may be the iconic form but in fact for cain has come in many shapes and sizes when lava breaks through a crack in the earth a mo