|
Portland Reef
The Portland Reef () is a submerged shoal not rising above the surface in the Gambier Islands in French Polynesia. It is located in the far southeast of the Tuamotu group archipelago, about 68 km southeast from the Gambier Islands, and 30 km SSE from Temoe Atoll, below the Tropic of Capricorn. The Portland Reef is made up of a submarine atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most ... structure lying at a depth of about 10 m. References |
Ocean Bank (topography)
An ocean bank, sometimes referred to as a fishing bank or simply bank, is a part of the seabed that is shallow compared to its surrounding area, such as a shoal or the top of an underwater hill. Somewhat like continental slopes, ocean bank slopes can upwell as tidal and other flows intercept them, sometimes resulting in nutrient-rich currents. Because of this, some large banks, such as Dogger Bank and the Grand Banks of Newfoundland, are among the richest fishing grounds in the world. There are some banks that were reported in the 19th century by navigators, such as Wachusett Reef, whose existence is doubtful. Types Ocean banks may be of volcanic nature. Banks may be carbonate or terrigenous. In tropical areas some banks are submerged atolls. As they are not associated with any landmass, banks have no outside source of sediments. Carbonate banks are typically platforms, rising from the ocean depths, whereas terrigenous banks are elevated sedimentary deposits. Seamounts, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gambier Islands
The Gambier Islands ( or ) are an archipelago in French Polynesia, located at the southeast terminus of the Tuamotu archipelago. They cover an area of , and are made up of the Mangareva Islands, a group of high islands remnants of a caldera along with islets on the surrounding fringing reef, and the uninhabited Temoe atoll, which is located 45 km (28 mi) south-east of the Mangareva Islands. The Gambiers are generally considered a separate island group from Tuamotu both because their culture and language (Mangarevan language, Mangarevan) are much more closely related to those of the Marquesas Islands, and because, while the Tuamotus comprise several chains of coral atolls, the Mangareva Islands are of volcanic origin with central high islands. Administratively, the Gambier Islands are inside the Communes of France, commune of Gambier (commune), Gambier, which also includes several atolls in the Tuamotu Archipelago. The town hall (''mairie'') of the commune of Gambier is located o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Polynesia
French Polynesia ( ; ; ) is an overseas collectivity of France and its sole #Governance, overseas country. It comprises 121 geographically dispersed islands and atolls stretching over more than in the Pacific Ocean, South Pacific Ocean. The total land area of French Polynesia is , with a population of 278,786 (Aug. 2022 census) of which at least 205,000 live in the Society Islands and the remaining population lives in the rest of the archipelago. French Polynesia is divided into five island groups: the Austral Islands; the Gambier Islands; the Marquesas Islands; the Society Islands (comprising the Leeward Islands (Society Islands), Leeward and Windward Islands (Society Islands), Windward Islands); and the Tuamotus. Among its 121 islands and atolls, 75 were inhabited at the 2017 census. Tahiti, which is in the Society Islands group, is the most populous island, being home to nearly 69% of the population of French Polynesia . Papeete, located on Tahiti, is the capital of French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuamotu
The Tuamotu Archipelago or the Tuamotu Islands (, officially ) are a French Polynesian chain of just under 80 islands and atolls in the southern Pacific Ocean. They constitute the largest chain of atolls in the world, extending (from northwest to southeast) over an area roughly the size of Western Europe. Their combined land area is . This archipelago's major islands are Rangiroa, Anaa, Fakarava, Hao and Makemo. The Tuamotus have approximately 16,000 inhabitants. The islands were initially settled by Polynesians, and modern Tuamotuans have inherited from them a shared culture and the Tuamotuan language. The Tuamotus are a French overseas collectivity. History The early history of the Tuamotu islands is generally unknown. Archaeological findings suggest that the western Tuamotus were settled from the Society Islands as early as 900 CE or as late as 1200 CE. DNA evidence suggests that they were settled about 1110 CE. On the islands of Rangiroa, Manihi and Mataiva, there ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temoe (Gambier Islands)
Temoe, or Te Moe, is a small atoll of the Gambier Islands in French Polynesia. It is located in the far southeast of the Tuamotu group archipelago. It lies about 37 km southeast from the Gambier Islands and more than southeast from Mataiva, at the other end of the Tuamotu archipelago. Temoe Atoll is trapezoidal in shape and bound by a continuous reef with many small shallow spillways. It is in length and has a maximum width of . The lagoon has a maximum depth of . Its islands are low and flat and the lagoon has no navigable pass to enter it. Temoe is permanently uninhabited. Administratively it belongs to the commune of the Gambier Islands. southwest of Temoe Atoll lies Portland Reef, a submerged shoal lying at a depth of about . History Temoe was formerly inhabited. There are ancient Polynesian archaeological remains on this lonely atoll; foremost among these are temple structures (marae). It is said that buccaneer Edward Davis might have arrived at Temoe and Mang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropic Of Capricorn
The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the subsolar point at the December (or southern) solstice. It is thus the southernmost latitude where the Sun can be seen directly overhead. It also reaches 90 degrees below the horizon at solar midnight on the June Solstice. Its northern equivalent is the Tropic of Cancer. The Tropic of Capricorn is one of the five major circles of latitude marked on maps of Earth. Its latitude is currently south of the Equator, but it is very gradually moving northward, currently at the rate of 0.47 arcseconds, or 15 metres, per year. Name When this line of latitude was named, the Sun was in the constellation Capricornus at the December solstice. This is the date each year when the Sun reaches zenith at this latitude, the southernmost declination it reaches for the year. (Due to the axial precession, precession of the equinoxes the Sun currently appears in Sagittarius (constellation), Sagittarius at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atoll
An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most of the approximately 440 atolls in the world are in the Pacific Ocean. Two different, well-cited models, the subsidence model and the antecedent karst model, have been used to explain the development of atolls.Droxler, A.W. and Jorry, S.J., 2021. "The Origin of Modern Atolls: Challenging Darwin's Deeply Ingrained Theory". ''Annual Review of Marine Science'', 13, pp. 537–573. According to Charles Darwin's subsidence model, the formation of an atoll is explained by the sinking of a volcanic island around which a coral fringing reef has formed. Over geologic time, the volcanic island becomes extinct and eroded as it subsides completely beneath the surface of the ocean. As the volcanic island subsides, the coral fringing reef becomes a ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landforms Of The Gambier Islands
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, structure stratification, rock exposure, and soil type. Gross physical features or landforms include intuitive elements such as berms, cliffs, hills, mounds, peninsulas, ridges, rivers, valleys, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
