Why do volcanoes explode??
Okay, volcanoes are big mounds of cooled lava rock that sit above a hole in the ground where magma is vented from inside the earth’s crust. Sort of like the crusty stuff that gathers around the hole on a ketchup or shampoo bottle. Now, magma (melted rock under the earth’s surface) is *really* hot stuff. It’s moving and mixing around under your feet and it’s full of gases. Being so deep in the earth’s crust, there is a lot of pressure building up. Usually, this pressure pushes magma up into cracks in the crust. Sometimes that’s the end of the story and the magma cools into a pluton that never reaches the surface. Other times, pressure will be so great that the magma will breach the crust and flow out onto the surface of the Earth. Think of squeezing an open ketchup bottle. EXPLOSIONS result when the holes that magma escape through (called vents) get plugged up with debris like rock or really sticky magma. Now, the volcano is like an inflating balloon that keeps filling with air. It gets
