Researchers have discovered four gigantic seamounts towering above the seafloor surrounding South America after detecting "gravitational anomalies" given off by the massive underwater mountains.

The highest peak here is more than 7,500 feet tall. Seamounts generally form when volcanic mountains rise up from the seafloor but fail to reach the surface (those that break the surface become ...

The tallest volcano in Europe, Italy's Mount Etna, and the world's most active volcano, Kilauea in Hawaii, erupting again.

The volcano, formerly called Loihi Seamount, is about 22 miles off the Big Island’s southeastern coast and will one day become the youngest of the Hawaiian Islands when it finally grows tall ...