What is the largest marine volcano on Earth?

William Sager, a marine geophysicist from the University of Houston began studying the Tamu Massif about twenty years ago. He and his team, a joint China-US team, published their findings in September 2013. The discovery is now considered as one of the most significant discoveries in the history of marine science.

At first thought to be made up of many individual structures, its been found to be one huge volcano. Because this goes against all previously thinking scientists are rethinking long-held beliefs about marine geology.

The Tamu Massif is 1,600 kilometers (about one thousand miles) east of Japan measuring about 280 by 400 miles (450 by 650 kilometers), or more than 120,000 square miles dwarfing the next largest active volcano on Earth, Mauna Loa in Hawaii, which measures about 2,000 square miles (5,200 square kilometers). That makes it about the size of Japan and except for Olympus Mons on Mars the largest known volcano in the solar system.

Tamu Massif is aproximately 145 million years old.