It's been nearly four years since a massive volcanic explosion rocked the Pacific nation of Tonga. The eruption created a ...

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 millions of people. Its mission: figure ...

A towering wall of fire brightened the night sky over the Caspian Sea on Sunday due in part to a unique geologic formation. Just after sunset on July 4, a large explosion and fireball could be seen ...