Washington state’s Mount St. Helens erupted catastrophically in 1980, killing 57 people. That eruption sent ash soaring over 80,000 feet and raining down as far as 250 miles away. Mauna Loa is not ...

Learn how magma, gas, and water drive eruptions; compare eruption and volcano types, understand warning signs, and follow ...

Volcanoes are grouped into four types: cinder cones, composite volcanoes, shield volcanoes and lava volcanoes. Cinder cones are circular or oval cones made up of small fragments of lava from a single ...

(CNN) — Here's some background information about volcanoes, mountains that open downward to a reservoir of molten rock. Facts: More than 80% of the Earth's surface, both above and below sea level, is ...