The largest unitary volcano ever found on Earth , with an area equivalent to the British Isles, is called Tamu Massif and is found under water 1,600 kilometers east of Japan. It was formed approximately 130 million years ago , is part of the Shatsky Rise range and occupies around 200,000 square kilometers of surface. In comparison, the area occupied by the Mauna Loa volcano in Hawaii represents only 2% of this mammoth underwater volcano.
According to its discoverers in the journal Nature Geoscience , Tamu Massif is almost as big as the giant volcanoes on Mars , making it one of the most voluminous in the solar system. Although until recently it was not clear whether the Tamu Massif was a single volcano or the set of many eruption points, the analysis of samples of the crust and data collected on board the ship JOIDES Resolution has confirmed that the mass of basalt that gives form Tamu Massif is the product of an eruption from a single source near the center.
