The West Mata volcano was discovered in May 2009 nearly 4,000 feet below the surface of the Pacific Ocean, in an area bounded by Fiji, Tonga and Samoa. It is the deepest erupting volcano discovered to date. This bathymetric map of the northeast section of the Lau Basin shows that West Mata volcano is not the largest volcano in the region, but according to recent observations it seems to be the most active. The summit of West Mata is nearly one mile deep, the base is nearly two miles deep. Tonga Trench is nearly seven miles deep.