Thought Yellowstone was big? Integrated Ocean Drilling Program finds volcano comparable to Olympus Mons

Scientists at the Integrated Ocean Drilling program have just discovered a massive volcano, the size of which puts the more famous super-volcano under Yellowstone park to shame. Located beneath the Pacific ocean, to the east of Japan, this volcano might be the largest volcano on earth, similar in size to the largest in the solar system: Olympus Mons, on Mars.

Thought to be formed by very large movements of the earth's mantle, Tamu Massif is merely the largest volcano on a volcanic plateau the size of California. Using magnetic and radioactive dating techniques, it's estimated that this plateau, named the Shatsky Rise, formed around 145 million years ago, putting it right at the boarder between the Triassic and Cretaceous periods of the earth's history.

The authors of the paper which announced this volcano commented:

It is remarkable that Tamu Massif reveals itself to be one enormous shield volcano. Oceanic plateaux have long been recognized as massive volcanic features, but the geometry of magma-supplying vent systems and lava flows has been unclear.

The authors went on to compare the volcano to the island of Hawaii, which although smaller, consists of five individual shield volcanoes, and  Iceland, which again, a composite of many volcanoes. Although they have long known that oceanic plateaus are volcanic, a single volcano of this size is surprising.

Sager et Al, 2013, see link below. The dark grey area on the map represents the outline of the base of Olympus Mons, for scale. In the cutout in the top left corner, the edge of Japan can be seen, giving an indication of just how large this volcano is. 

This of course raises the question as to whether we should be expecting the Tamu Massif to take over from Yellowstone, as the great doomsday in our collective imagination. Whilst there appears to be no danger of eruption from Tamu Massif erupting in reality, this of course is no barrier to our disaster film-makers (Sharknado anyone?). More likely, the lack of interesting scenery (being located square in the Pacific ocean) will be the limiting attribute.

Sources:
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1934.html