Called Tamu Massif, this enormous dormant or inactive volcano is located within the huge underwater mountain range called Shatsky Rise formation about 1609 kilometers east of Japan. It covers an area of about 311,000 square kilometers of ocean bottom some 1981 meters to 6.5 kilometers below the water’s surface.


Tamu Massif covers an area that's roughly equivalent to the size of the British Isles or the U.S. state of New Mexico and it is among the most massive volcanoes found so far in the solar system.


Right now, Mount Olympus on Mars takes the top spot for biggest volcano in the solar system, according to the researchers.


“Tamu Massif is the biggest single shield volcano ever discovered on Earth,” said the University of Houston’s William Sager, who led the research. “There may be larger volcanoes, because there are bigger igneous features out there such as the Ontong Java Plateau, but we don’t know if these features are one volcano or complexes of volcanoes.”


Tamil Massif has been known to exist for some time but what wasn’t clear was whether it was a single volcano or a collection of multiple eruption points.


Data collected aboard the science research ship, JOIDES Resolution, helped researchers determine Tamu Massif did erupt from one single source located near its center.


Tamu Massif is the largest feature of the Shatsky Rise, which was created by the eruption of several underwater volcanoes 130 to 145 million years ago. The giant volcano, according to the researchers, may have become inactive a few million years after it was formed.


The volcano is unique, compared to other underwater volcanoes, not just because if its huge size, but because of how it’s shaped. It is low and wide, which means when it erupted, its lava probably flowed longer distances than other volcanoes on Earth.


“It’s not high, but very wide, so the flank slopes are very gradual,” Sager said. “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. Before now, we didn’t know this because oceanic plateaus are huge features hidden beneath the sea. They have found a good place to hide.”


Since Sager began studying the underwater volcano about 20 years ago while at Texas A&M, he decided to name it after the university. Tamu Massif is a combination of an abbreviation of Texas A&M University and the French word for massive, which is also a geological term for large mountain mass.



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World's Largest Single Volcano Found Off Japan Coast