A list of active and extinct submarine volcanoes and seamounts located under the world's oceans. There are estimated to be 40,000 to 55,000 seamounts in the global oceans. [1] Almost all are not well-mapped and many may not have been identified at all. Most are unnamed and unexplored. This list is therefore confined to seamounts that are notable enough to have been named and/or explored.
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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.
Farallón de Pájaros, also known as Uracus or Urracas, is a small (2.3 km2) uninhabited volcanic island, the northernmost island and also farthest west in the Northern Mariana Islands chain.
Kamaʻehuakanaloa Seamount is an active submarine volcano about 22 mi (35 km) off the southeast coast of the island of Hawaii. The top of the seamount is about 3,200 ft (975 m) below sea level. This seamount is on the flank of Mauna Loa, the largest active subaerial shield volcano on Earth. Kamaʻehuakanaloa is the newest volcano in the Hawaiian–Emperor seamount chain, a string of volcanoes that stretches about 3,900 mi (6,200 km) northwest of Kamaʻehuakanaloa. Unlike most active volcanoes in the Pacific Ocean that make up the active plate margins on the Pacific Ring of Fire, Kamaʻehuakanaloa and the other volcanoes of the Hawaiian–Emperor seamount chain are hotspot volcanoes and formed well away from the nearest plate boundary. Volcanoes in the Hawaiian Islands arise from the Hawaii hotspot, and as the youngest volcano in the chain, Kamaʻehuakanaloa is the only Hawaiian volcano in the deep submarine preshield stage of development.
Protector Shoal is the shallowest point of the Protector Seamounts, a group of submarine volcanoes in the Southern Ocean. They are part of the South Sandwich island arc, a volcanic arc that has given rise to the South Sandwich Islands. Protector Shoal reaches a depth of 55 metres (180 ft) below sea level and is part of a larger group of seamounts that formed atop a larger ridge. Some of these seamounts bear traces of sector collapses, and one is capped by nested calderas.
Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ridges alone are estimated to account for 75% of the magma output on Earth. Although most submarine volcanoes are located in the depths of seas and oceans, some also exist in shallow water, and these can discharge material into the atmosphere during an eruption. The total number of submarine volcanoes is estimated to be over one million of which some 75,000 rise more than 1 kilometre (0.62 mi) above the seabed. Only 119 submarine volcanoes in Earth's oceans and seas are known to have erupted during the last 11,700 years.
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified.
James Healy Seamount is a submarine volcano located among the South Kermadec Ridge Seamounts south of New Zealand's Kermadec Islands. It consists of a volcanic cone that reaches a depth of 1,150 metres (3,770 ft) below sea level, two 2–2.5 kilometres (1.2–1.6 mi) and 1.3 kilometres (0.81 mi) wide calderas and a parasitic cone that reaches a depth of 950 metres (3,120 ft) below sea level. The flanks of the volcano are covered with pumice and volcanic rocks, and hydrothermal venting occurs inside the caldera.
Adams Seamount is a submarine volcano above the Pitcairn hotspot in the central Pacific Ocean about 100 kilometres (62 mi) southwest of Pitcairn Island.
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 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.
Marsili is a large undersea volcano in the Tyrrhenian Sea, about 175 kilometers (109 mi) south of Naples. The seamount is about 3,000 m tall; its peak and crater are about 450 m below the sea surface. Though it has not erupted in recorded history, volcanologists believe that Marsili is a relatively fragile-walled structure, made of low-density and unstable rocks, fed by the underlying shallow magma chamber. Volcanologists with the Italian National Institute of Geophysics and Volcanology (INGV) announced on March 29, 2010, that Marsili could erupt at any time, and might experience a catastrophic collapse that would suddenly release vast amounts of magma in an undersea eruption and landslide that could trigger destructive tsunamis on the Italian coast and nearby Mediterranean coastlines.
The Tasmantid Seamount Chain is a 2,000 km (1,200 mi) long chain of seamounts in the South Pacific Ocean. The chain consists of over 16 extinct volcanic peaks, many rising more than 4,000 m (13,000 ft) from the seabed. It 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.
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.
Monowai Seamount is a volcanic seamount to the north of New Zealand. It is formed by a large caldera and a volcanic cone just south-southeast from the caldera. The volcanic cone rises to depths of up to 100 metres (330 ft) but its depth varies with ongoing volcanic activity, including sector collapses and the growth of lava domes. The seamount and its volcanism were discovered after 1877, but only in 1980 was it named "Monowai" after a research ship of the same name.
The geology of the Canary Islands is dominated by volcanoes and volcanic rock. The Canary Islands are a group of volcanic islands in the North Atlantic Ocean, near the coast of Northwest Africa. The main islands are Lanzarote, Fuerteventura, Gran Canaria, Tenerife, La Gomera, La Palma, and El Hierro. There are also some minor islands and islets. The Canary Islands are on the African tectonic plate but they are far from the plate's edges; this controls the type of volcanic activity, known as intraplate volcanism, that has formed the islands.
Kaitoku Seamount is an active submarine complex volcano located in the Bonin Islands of Japan.
Ahyi Seamount is an active shallow submarine volcano in the Northern Mariana Islands, in the Northwestern Pacific Ocean. It has erupted 3 times since the year 2000; in 2001, 2014 and 2022–23. Since 2009, it has been a part of Marianas Trench Marine National Monument of the United States.
MRGID 5093
