Seamount off Japan could be the largest volcano in the solar system
Underwater mountain off Japanese coast could be biggest volcano on earth and may rival Mars' Olympus Mons as largest in entire solar system
A seamount in the northwest Pacific Ocean may be the largest volcano on earth, and could rival the largest in the solar system - the mighty Olympus Mons on Mars - oceanographers say.
Sager and team members had long ago given names to the formations jutting up from the Shatsky Rise, a California-size oceanic plateau southeast of Japan. Tamu, the largest of three major features, stands for Texas A&M University, where Sager conducted his research for two decades before moving recently to the University of Houston.
Tens of thousands of seamounts pockmark the ocean floors, and others may be larger, such as the Ontong Java Plateau near the Solomon Islands and the Kerguelen Plateau in the southern Indian Ocean. But thus far, none appears to be a single basalt shield volcano, but rather a composite of many such volcanoes, Sager said.
"One of the real things you have as a marine geologist or marine geophysicist is that these things have found a good place to hide," Sager said. "It's easier to study something on the surface of Mars in many ways than it is to study something that's right out there in the ocean. It's not like we didn't know that there was something out there. It's just taken generations to get the time and money and to focus on it and get out there and study it."
Sager's team drilled core samples from the volcano, jutting from the ocean floor about 6.5 kilometres deep. Tamu rises about 3,900 metres. But much of its mass has sunk into the ocean crust, making it far shorter than Olympus Mons, which towers about 21,000 metres from the more rigid Martian surface.
But Tamu appears to have a larger base. Olympus Mons is about 600 kilometres in diameter, according to Nasa; Tamu spans about 645 kilometres at its widest point and covers about 20,000 more square kilometres, according to the study.
