‘Scientists have discovered a staggering colossus that once spewed fire but now slumbers deep in the Pacific Ocean,… a volcano with a footprint comparable to Olympus Mons on Mars, the largest volcano in the solar system. Covering an area of 120,000 square miles, which makes it about the size of New Mexico or the British Isles, the formation dubbed Tamu Massif is one of the biggest ever found, according to a study led by University of Houston professor William Sager.

Hawaii’s Mauna Loa, the largest active volcano on Earth, is taller than Tamu Massif but has only about 2 percent of its area… Tamu’s summit is roughly 6,500 feet below the ocean’s surface. Most of the formation is thought to be in waters that are nearly 4 miles deep.’  (Crave – CNET).