Most volcanoes form at the boundaries of Earth's tectonic plates, which are huge slabs of crust and upper mantle that fit together like puzzle pieces. Think of these plates as massive rafts floating ...

To see active volcanoes, head to a U.S. National Park that preserves volcanoes or parts of volcanoes. Volcanoes are ex ...

Over millions of years, the Earth’s upper layers have performed a dance that has created mountains, volcanoes, continents, ridges and ocean trenches. Tectonic plates play a key role in this process.