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 ...

Olympus Mons is a shield volcano so broad that a person standing on its lower slope would not see the summit above the horizon. Its summit rises roughly 16 miles above the surrounding Martian plains, ...

Take a tour of the space volcanoes on other planets and moons across the Solar System, and find out how they differ from Earth's volcanoes. While volcanoes have brought profound changes to landscapes ...

Add Yahoo as a preferred source to see more of our stories on Google. Smoke billows from the mouth of Mt. Shasta like a thunderous cough. Within moments, clear skies turn gray, and the sun vanishes ...