(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 ...

Hidden amid the hills of Illinois is a dormant Volcano with a massive 10-mile-wide crater and teeming with rare and igneous ...

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 ...

This photo provided by the U.S. Geological Survey shows the summit lava lake of Hawaii's Kilauea volcano on May 6, 2018. By analyzing the dynamics of a string of explosions that happened during 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 ...

The volcano Uturuncu, located in the Central Andes mountains, has seemingly risen from the dead. While the volcano has not erupted in more than 250,000 years, it has recently shown signs of activity ...

Phreatic eruptions are a potentially lethal type of volcanic activity that is notoriously difficult to forecast. Understanding the complex processes that make eruptions more likely is a key step ...