Macdonald seamount

Macdonald seamount
South Pacific Ocean
Summit depth	40m
Height	Varies
Location
Location	South Pacific Ocean
Coordinates	28°58.7′S 140°15.5′W / 28.9783°S 140.2583°W / -28.9783; -140.2583[1]
Geology
Type	Seamount
Last eruption	1987-89
History
Discovery date	1967

Macdonald seamount (named after Gordon A. Macdonald) is a seamount in Polynesia, southeast of the Austral Islands and in the neighbourhood of a system of seamounts that include the Ngatemato seamounts and the Taukina seamounts. It rises 4,200 metres (13,800 ft) from the seafloor to a depth of about 40 metres (130 ft) and has a flat top, but the height of its top appears to vary with volcanic activity. There are some subsidiary cones such as Macdocald seamount. The seamount was discovered in 1967 and has been periodically active with gas release and seismic activity since then. There is hydrothermal activity on Macdonald, and the vents are populated by hyperthermophilic bacteria.

Macdonald seamount is the currently active volcano of the Macdonald hotspot, a volcanic hotspot that has formed this seamount and some other volcanoes. Eruptions occurred in 1967, 1977, 1979–1983 and 1987–1989, and earthquakes were recorded in 2007. The activity, which has produced basaltic rocks, has modified the shape of the volcano and may lead to the formation of an island in the future.