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 ...

At any given time, 20 to 50 of these active volcanoes are erupting. The proximity of people and buildings makes it important to study volcanoes and understand the hazards. The center of the Earth is ...

POPOCATÉPETL VOLCANO, Mexico (AP) — In the predawn darkness, a team of scientists climbs the slope of Mexico’s Popocatépetl volcano, one of the world’s most active and whose eruption could affect ...