Tamu Massi: the size of Japan or California

The largest volcano on Planet Earth has been found under the Pacific Ocean, about 1,000 miles (1,600 kilometers) east of Japan.


Tamu Massif measures about 280 by 400 miles (450 by 650 kilometers), or more than 100,000 square miles (259,000 square kilometers).

Its top lies about 6,500 feet below the ocean surface, and the total area of the rise is similar to Japan or California. The base extends down to about 4 miles (6.4 kilometers) deep.

The largest active volcano on Earth, Mauna Loa in Hawaii, measures about 2,000 square miles (5,200 square kilometers).

"Tamu Massif has been hiding out for 145 million years because it found a good place to hide", says William Sager, geology professor at the University of Houston, in Texas.

The newly discovered underwater peak not only is the biggest volcano on Earth, but it is also one of the biggest in the solar system.