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 Axial Seamount, an underwater volcano about 300 miles off the ... according to the USGS Hawaiian Volcano Observatory. And Mount Etna, the tallest volcano in Europe, erupted on Feb. 8 and again two ...

Although the Kamaehuakanaloa Seamount has been a little restless recently, new information about the undersea volcano is ...

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 ...