There is a new largest volcano in the solar system and it has been discovered on Earth, Nature.com reported.

Tamu Massif was found underwater, inactive for 140 million years, in the northwest Pacific Ocean. It is 650 kilometers wide, which is just bigger than Olympus Mons, a 625 kilometer-wide volcano on Mars.

Tamu Massif is now the largest volcano on Earth and the largest known one in the solar system. The study will be published Saturday in Nature Geoscience.

"This says that here on Earth we have analogous volcanoes to the big ones we find on Mars," said William Sager, a marine geologist at the University of Houston in Texas. "I'm not sure anybody would have guessed that."

The massive volcano was previously believed to be a mountain built from the eruptions of several other volcanoes. The mountain, rising four kilometers off the sea floor, would not be unique, as the islands of Hawaii and Iceland were formed that way.

Sager and his team sent the Marcus G. Langseth research vessel to examine Tamu Massif in 2010 and 2012. What the vessel found was the lava had apparently flowed away from the mountain, suggesting the underwater giant has a magma vent.

"From whatever angle you look at it, the lava flows appear to come from the centre of this thing," said Sager.

The volcano got its name from Texas A&M University's acronym (TAMU), reported the TAMU Times. Sager had worked for the school for 29 years in the College of Geosciences. Sager named the volcano after the school, along with the term "massif," which means "massive" in French.

"What is unusual about the volcano is its slope - it's not high, but very wide, so the flank slopes are very gradual," Sager told the TAMU Times. "In fact, if you were standing on its flank, you would have trouble telling which way is downhill. We know that it is a single immense volcano constructed from massive lava flows that emanated from the center of the volcano to form a broad, shield-like shape."

Sager explained how the shape and how it may have formed, saying it is important for scientists to understand how Earth's interior works.

"Its shape is different from any other sub-marine volcano found on Earth, and it's very possible it can give us some clues about how massive volcanoes can form," Sager said. "An immense amount of magma came from the center, and this magma had to have come from the Earth's mantle. So this is important information for geologists trying to understand how the Earth's interior works."