Supply Reef
Description
Supply Reef is a submerged circular reef of volcanic origin in the Northern Mariana Islands chain, about 10 kilometres (6 mi) NW of the Maug Islands. Presently, this igneous seamount is roughly 8 metres (26 ft) below the ocean's surface and about 100 m (300 ft) in diameter. Apparent episodes of submarine volcanism were noted on December 22–24 and 26–27 in 1989.