(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 ...

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 ...

Learn about how volcanoes are formed and the ways they erupt Chiara Maria Petrone, Roberto Scandone, and Alex Whittaker On February 20, 1943, Dionisio Pulido and his family were working in their ...

Mount Etna is like no other volcano on Earth, new research finds. In fact, the volcano may have formed in a bizarre way, reminiscent of how some seamounts, called petit-spot volcanoes, grow on the ...

An eruption forecast is a probabilistic assessment of the likelihood and timing of volcanic activity. The forecast may also include information about the expected style of activity (Section 1.6), the ...

California has seven active volcanoes, each with a unique eruption history, categorized by type and threat level. The USGS monitors these volcanoes, providing information to authorities and the public ...