Why and How
Volcanoes Erupt back to home page
Volcanoes are openings in the earth's crust. When the volcano erupts, gas and rocks come out of the opening. The rock is very hot, so it is *molten, which means melted. Scientists call this melted rock *magma. Crystals and minerals are in the rock, but the crystals dissolve because it is so hot. When the magma gets to the surface, it is called *lava. When the lava hardens, it is called *lava rock.
There are pockets of magma underneath the earth in some parts of the world. The magma presses against rock the earth's crust. When the magma finds a spot in the crust where there aren't very many rocks, it pushes to the surface.
*CRUST- the outermost layer of the earth
*MOLTEN- melted rock and minerals
*MAGMA- Melted rock and gas
*LAVA-Magma when it reaches the surface
*LAVA ROCK- Hardened lava