The Samoan archipelago is a chain of 16 islands and numerous seamounts covering 3,123 km2 (1,206 sq mi) in the central South Pacific, south of the equator, about halfway between Hawaii and New Zealand, forming part of Polynesia and of the wider region of Oceania. The islands are Savaiʻi, Upolu, Tutuila, ’Uvea, Taʻū, Ofu, Olosega, Apolima, Manono, Nuʻutele, Niulakita, Nuʻulua, Namua, Fanuatapu, Rose Atoll, Nu'ulopa, as well as the submerged Vailuluʻu, Pasco banks, and Alexa Bank.
The Pacific-Antarctic Ridge is a divergent tectonic plate boundary located on the seafloor of the South Pacific Ocean, separating the Pacific Plate from the Antarctic Plate. It is regarded as the southern section of the East Pacific Rise in some usages, generally south of the Challenger Fracture Zone and stretching to the Macquarie Triple Junction south of New Zealand.
The Lord Howe Seamount Chain formed during the Miocene. It features many coral-capped guyots and is one of the two parallel seamount chains alongside the east coast of Australia; the Lord Howe and Tasmantid seamount chains both run north-south through parts of the Coral Sea and Tasman Sea. These chains have longitudes of approximately 159°E and 156°E respectively.
The Hawaiʻi hotspot is a volcanic hotspot located near the namesake Hawaiian Islands, in the northern Pacific Ocean. One of the best known and intensively studied hotspots in the world, the Hawaii plume is responsible for the creation of the Hawaiian–Emperor seamount chain, a 6,200-kilometer (3,900 mi) mostly undersea volcanic mountain range. Four of these volcanoes are active, two are dormant; more than 123 are extinct, most now preserved as atolls or seamounts. The chain extends from south of the island of Hawaiʻi to the edge of the Aleutian Trench, near the eastern coast of Russia.
The Pitcairn hotspot is a volcanic hotspot located in the south-central Pacific Ocean. Over the past 11 million years, it has formed the Pitcairn-Gambier hotspot chain. It is responsible for creating the Pitcairn Islands and two large seamounts named Adams and Bounty, as well as atolls at Moruroa, Fangataufa and the Gambier Islands. The hotspot is currently located at Adams and Bounty, which are ~60 kilometers East-Southeast of Pitcairn Island.
The Louisville Ridge, often now referred to as the Louisville Seamount Chain, is an underwater chain of over 70 seamounts located in the Southwest portion of the Pacific Ocean. As one of the longest seamount chains on Earth it stretches some 4,300 km (2,700 mi) from the Pacific-Antarctic Ridge northwest to the Tonga-Kermadec Trench, where it subducts under the Indo-Australian Plate as part of the Pacific Plate. The chains formation is best explained by movement of the Pacific Plate over the Louisville hotspot although others had suggested by leakage of magma from the shallow mantle up through the Eltanin fracture zone, which it follows closely for some of its course.
The Marquesas hotspot is a volcanic hotspot in the southern Pacific Ocean. It is responsible for the creation of the Marquesas Islands – a group of eight main islands and several smaller ones – and a few seamounts. The islands and seamounts formed between 5.5 and 0.4 million years ago and constitute the northernmost volcanic chain in French Polynesia.
The Samoa hotspot is a volcanic hotspot located in the south Pacific Ocean. The hotspot model describes a hot upwelling plume of magma through the Earth's crust as an explanation of how volcanic islands are formed. The hotspot idea came from J. Tuzo Wilson in 1963 based on the Hawaiian Islands volcanic chain.
The Macdonald hotspot is a volcanic hotspot in the southern Pacific Ocean. The hotspot was responsible for the formation of the Macdonald Seamount, and possibly the Austral-Cook Islands chain. It probably did not generate all of the volcanism in the Austral and Cook Islands as age data imply that several additional hotspots were needed to generate some volcanoes.
The Society hotspot is a volcanic hotspot in the south Pacific Ocean which is responsible for the formation of the Society Islands, an archipelago of fourteen volcanic islands and atolls spanning around 720 kilometres (450 mi) of the ocean which formed between 4.5 and <1 Ma.
The Mid-Pacific Mountains (MPM) is a large oceanic plateau located in the central North Pacific Ocean or south of the Hawaiian–Emperor seamount chain. Of volcanic origin and Mesozoic in age, it is located on the oldest part of the Pacific Plate and rises up to 2 km (1.2 mi) above the surrounding ocean floor and is covered with several layers of thick sedimentary sequences that differ from those of other plateaux in the North Pacific. About 50 seamounts are distributed over the MPM. Some of the highest points in the range are above sea level which include Wake Island and Marcus Island.
Arago hotspot is a hotspot in the Pacific Ocean, presently located below the Arago seamount close to the island of Rurutu, French Polynesia.
Ngatemato seamounts are a series of seamounts in the southern Pacific Ocean.
Foundation Seamounts are a series of seamounts in the southern Pacific Ocean. Discovered in 1992, these seamounts form a 1,350 kilometres (840 mi) long chain which starts from the Pacific-Antarctic Ridge. Some of these seamounts may have once emerged from the ocean.
Macdonald seamount 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.
Musicians Seamounts are a chain of seamounts in the Pacific Ocean, north of the Hawaiian Ridge. There are about 65 seamounts, some of which are named after musicians. These seamounts exist in two chains, one of which has been attributed to a probably now-extinct hotspot called the Euterpe hotspot. Others may have formed in response to plate tectonics associated with the boundary between the Pacific Plate and the former Farallon Plate.
President Thiers Bank is a broad guyot, which lies northwest of Rapa and 200 kilometres (120 mi) southeast of Raivavae, in the Austral Islands. Its summit reaches a depth of 33 metres (108 ft). It may have been created by the Macdonald hotspot. Another theory sees in the seamount the endpoint of an alignment that starts with Aitutaki and also involves one volcanic phase at Raivavae.
Magellan Rise is an oceanic plateau in the Pacific Ocean, which covers a surface area of 500,000 square kilometres (190,000 sq mi). There is another geological structure with the same name west from the Marshall Islands.
The Rarotonga hotspot is a volcanic hotspot in the southern Pacific Ocean. The hotspot is claimed to be responsible for the formation of Rarotonga and some volcanics of Aitutaki but an alternative explanation for these islands most recent volcanics has not been ruled out. Recently alternatives to hotspot activity have been offered for several other intra-plate volcanoes that may have been associated with the Rarotonga hotspot hypothesis.
Profundiconus tarava is a species of sea snail, a marine gastropod mollusk, in the family Conidae, the cone snails and their allies.
