Largest volcano on earth discovered by a group of scientist beneath the Pacific Ocean, was revealed in the latest issue of the Nature Geoscience.

The largest volcano on discovered on earth is called the Tamu Massif, which dwarfs the previous record holder, Hawaii's Mauna Loa. It is only 25 percent smaller than Olympus Mons on Mars, which is the biggest volcano in Earth's solar system, William Sager said in the magazine. Sager is the lead study author and a geologist at the University of Houston.

"We think this is a class of volcano that hasn't been recognized before," Sager said about the largest volcano on earth discovered by him and his fellow scientist. "The slopes are very shallow. If you were standing on this thing, you would have a difficult time telling which way was downhill."

Tamu is 400 miles wide but only about 2.5 miles tall. It erupted for a few million years during the early Cretaceous period, about 144 million years ago, and has been extinct since then, according to the researcher's report.

"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.

Sager and the other researchers have been studying the Shatsky Rise for years and the whole time believed that the Tamu was always a part of it. They thought it was oceanic plateau, which are massive piles of lava whose origins are still a matter of active scientific debate.

"In the case of Shatsky Rise, it formed on virtually zero thickness lithosphere, so it's in isostatic balance," Sager said. "It's basically floating all the time, so the bulk of Tamu Massif is down in the mantle. The Hawaiian volcanoes erupted onto thick lithosphere, so it's like they have a raft to hold on to. They get up on top and push it down. And with Olympus Mons, it's like it formed on a two-by-four."