Tamu Massif is a seamount in the northwest Pacific Ocean, sitting atop a triple junction of mid-ocean ridges. Tamu Massif is located in the Shatsky Rise about 1,600 km (990 mi) east of Japan. The massif covers an area of about 553,000 square kilometres (214,000 sq mi). Its summit is about 1,980 m (6,500 ft) below the surface of the ocean, and its base extends to about 6.4 km (4.0 mi) deep. It is about 4,460 metres (14,620 ft) tall.
|Summit depth||1,980 metres (6,500 ft)|
|Height||4,460 metres (14,620 ft)|
|Location||Northwest Pacific Ocean|
|Type||Seamount (underwater volcano), shield volcano|
|Age of rock||144.6 ± 0.8 Ma|
William Sager, a marine geophysicist from the Department of Earth and Atmospheric Sciences at the University of Houston, began studying Tamu Massif in about 1993 at the Texas A&M College of Geosciences. In September 2013, Sager and his team concluded that Tamu Massif is "the biggest single shield volcano ever discovered on Earth". Other igneous features on the planet are larger, such as the Ontong Java Plateau, but it has not yet been determined if they are indeed just one volcano or rather complexes of several volcanoes.