(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 that dominate postcards and disaster movies are often the ones we can see, their peaks etched against the sky. Yet some of the most consequential volcanic threats on Earth are hidden under ...

A dormant volcano in Ethiopia erupted after 10,000 years of silence. This event shows how the world's little-known volcanoes pose the greatest threat.

Lava is molten rock from a volcano that reaches the Earth’s surface. Liquid rock below the Earth’s surface is referred to as magma. More than 50% of the world’s active volcanoes above sea level ...