Related Research Articles
A seamount is a large submarine landform that rises from the ocean floor without reaching the water surface, and thus is not an island, islet, or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to 1,000–4,000 m (3,300–13,100 ft) in height. They are defined by oceanographers as independent features that rise to at least 1,000 m (3,281 ft) above the seafloor, characteristically of conical form. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat-top seamounts are called "guyots" or "tablemounts".
The New Georgia Islands are part of the Western Province of Solomon Islands. They are located to the northwest of Guadalcanal. The larger islands are mountainous and covered in rain forest. The main islands are New Georgia, Vella Lavella, Kolombangara, Ghizo, Vangunu, Rendova and Tetepare. They are surrounded by coral reefs and include the Marovo Lagoon.
The Hawaiian–Emperor seamount chain is a mostly undersea mountain range in the Pacific Ocean that reaches above sea level in Hawaii. It is composed of the Hawaiian ridge, consisting of the islands of the Hawaiian chain northwest to Kure Atoll, and the Emperor Seamounts: together they form a vast underwater mountain region of islands and intervening seamounts, atolls, shallows, banks and reefs along a line trending southeast to northwest beneath the northern Pacific Ocean. The seamount chain, containing over 80 identified undersea volcanoes, stretches about 6,200 km (3,900 mi) from the Aleutian Trench in the far northwest Pacific to the Kamaʻehuakanaloa Seamount, the youngest volcano in the chain, which lies about 35 kilometres (22 mi) southeast of the Island of Hawaiʻi.
In geology, hotspots are volcanic locales thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle. Examples include the Hawaii, Iceland, and Yellowstone hotspots. A hotspot's position on the Earth's surface is independent of tectonic plate boundaries, and so hotspots may create a chain of volcanoes as the plates move above them.
Geologically, a volcanic island is an island of volcanic origin. The term high island can be used to distinguish such islands from low islands, which are formed from sedimentation or the uplifting of coral reefs.
The Pukao Seamount is a submarine volcano, the most westerly in the Easter Seamount Chain or Sala y Gómez ridge. To the east are Moai (seamount) and then Easter Island. It rises over 2,500 metres from the ocean floor to within a few hundred metres of the sea surface. The Pukao Seamount is fairly young, and believed to have developed in the last few hundred thousand years as the Nazca Plate floats over the Easter hotspot.
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.
Penguin Bank is the name given to a now-submerged shield volcano of the Hawaiian Islands. Its coral-capped remains lie immediately west of the island of Molokaʻi, under relatively shallow water.
Ndai is an island in the Solomon Islands; it is located in Malaita Province. It was formerly known as Gower Island.
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 Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific Plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth.
Arago hotspot is a hotspot in the Pacific Ocean, presently located below the Arago seamount close to the island of Rurutu, French Polynesia.
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.
Lo-En or Hess is an Albian–Campanian guyot in the Marshall Islands. One among a number of seamounts in the Pacific Ocean, it was probably formed by a hotspot in what is present-day French Polynesia. Lo-En lies southeast of Eniwetok which rises above sea level, and Lo-En is almost connected to it through a ridge.
Daiichi-Kashima Seamount is a guyot in the Pacific Ocean off Japan. It is about 3.5 kilometres (2.2 mi) high and reaches a depth of 3,540 metres (11,610 ft). Daiichi-Kashima formed during the Barremian as a result of volcanic activity; during the Albian reefs formed on the seamount and generated a limestone cap. The seamount later.
Vailuluʻu is a volcanic seamount discovered in 1975. It rises from the sea floor to a depth of 593 m (1,946 ft) and is located between Taʻu and Rose islands at the eastern end of the Samoa hotspot chain. The basaltic seamount is considered to mark the current location of the Samoa hotspot. The summit of Vailuluʻu contains a 2 km wide, 400 m deep oval-shaped caldera. Two principal rift zones extend east and west from the summit, parallel to the trend of the Samoan hotspot. A third less prominent rift extends southeast of the summit.
Kaitoku Seamount is an active submarine complex volcano located in the Bonin Islands of Japan.
References
- ↑ "Coleman Seamount". Global Volcanism Program . Smithsonian Institution . Retrieved 2021-06-28.
- ↑ "Coleman Seamount, Solomon Islands - John Seach".
| Authority control databases: Geographic |
|---|
