Animated guide: Volcanoes.
Volcanoes. Anyone who has witnessed a volcano erupting needs no further evidence to know that Earth is a dynamic planet.
Volcanoes are one of the major mechanisms for creating new crust. They are powerful, breathtaking, and dangerous, and offer scientists an unparalleled glimpse at Earth's interior. Although the processes that form magma are not well understood, volcanoes — and the igneous rocks they produce — can be studied and explained in the context of plate tectonics.