Supply Reef is a submerged circular

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

of volcanic origin in the

Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI; ch, Sankattan Siha Na Islas Mariånas; cal, Commonwealth Téél Falúw kka Efáng llól Marianas), is an unincorporated territory and commonw ...

chain, about NW of the

Maug Islands Maug (from the Chamorro name for the islands, Ma'ok, meaning "steadfast" or "everlasting") consists of a group of three small uninhabited islands. This island group is part of the Northern Islands Municipality of the Commonwealth of the Northern ...

. Presently this igneous

seamount A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...

is roughly below the ocean's surface and about in diameter. Apparent episodes of submarine volcanism were noted on December 22–24 and 26–27 in 1989. Txu-pclmaps-oclc-22834566 j-14b

References

* Geography of the Northern Mariana Islands Volcanoes of the Northern Mariana Islands Submarine volcanoes Reefs of the Pacific Ocean Seamounts of the Pacific Ocean Reefs of the United States Former islands from the last glacial maximum {{NorthernMarianas-geo-stub