New Giant Volcano Below Sea Is Largest in the world

A volcano the size of New Mexico or the British Isles has been identified under the Pacific Ocean, about 1,000 miles (1,600 kilometers) east of Japan, making it the biggest volcano on Earth and one of the biggest in the solar system.

Called Tamu Massif, the giant shield volcano had been thought to be a composite of smaller structures, but now scientists say they must rethink long-held beliefs about marine geology.