World’s largest volcano lurks beneath Pacific Ocean

The dormant behemoth may rival ones on Mars

The most massive volcano in the world, with a footprint the size of New Mexico, crouches in the dark depths of the western Pacific Ocean. With its hollowed peak lying beneath 2 kilometers of water, Tamu Massif, a basaltic mound, may rival the largest known volcano in the solar system: Mars’ Olympus Mons.