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Volcanic Island
Geologically, a high island or volcanic island is an island of volcanic origin. The term can be used to distinguish such islands from low islands, which are formed from sedimentation or the uplifting of coral reefs (which have often formed on sunken volcanos). Definition and origin There are a number of "high islands" that rise no more than above sea level, often classified as "islets or rocks", while some low islands, such as Banaba, Henderson Island, Makatea, Nauru, and Niue, as uplifted coral islands, rise over above sea level. The two types of islands are often found in proximity to each other, especially among the islands of the South Pacific Ocean, where low islands are found on the fringing reefs that surround most high islands. Volcanic islands normally arise above a hotspot. Habitability High islands above a certain size usually have fresh groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moorea ISS006
Moorea ( or ; Tahitian: ), also spelled Moorea, is a volcanic island in French Polynesia. It is one of the Windward Islands, a group that is part of the Society Islands, northwest of Tahiti. The name comes from the Tahitian word , meaning "yellow lizard": = lizard ; (from ) = yellow. An older name for the island is ', sometimes spelled or (among other spellings that were used by early visitors before Tahitian spelling was standardized). Early Western colonists and voyagers also referred to Moorea as ''York Island'' or ''Santo Domingo''. History Prehistory According to recent archaeological evidence, the Society Islands were probably settled from Samoa and Tonga around 200 CE.Patrick V. Kirch: ''On the Road of the Wind - An Archaeological History of the Pacific Islands Before European Contact'', University of California Press, Berkeley-Los Angeles-London 2000 Nine tribal principalities emerged in the enclosed valleys, which in turn were subdivided into individual cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banaba
BanabaThe correct spelling and etymology in Gilbertese should be ''Bwanaba'' but the Constitution of Kiribati writes Banaba. Because of the spelling in English or French, the name was very often written Paanapa or Paanopa, as it was in 1901 Act. (; also Ocean Island) is an island of Kiribati in the Pacific Ocean. A solitary raised coral island west of the Gilbert Island Chain, it is the westernmost point of Kiribati, lying east of Nauru, which is also its nearest neighbour. It has an area of , and the highest point on the island is also the highest point in Kiribati, at in height. Along with Nauru and Makatea (French Polynesia), it is one of the important elevated phosphate-rich islands of the Pacific. History According to ''Te Rii ni Banaba—The Backbone of Banaba'' by Raobeia Ken Sigrah, Banaban oral history supports the claim that the people of the Te Aka clan, which originated in Melanesia, were the original inhabitants of Banaba (Ocean Island), having arrived befor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology. Typically, groundwater is thought of as water flowing through shallow aquifers, but, in the technical sense, it can also contain soil moisture, perma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hotspot (geology)
In geology, hotspots (or hot spots) 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. There are two hypotheses that attempt to explain their origins. One suggests that hotspots are due to mantle plumes that rise as thermal diapirs from the core–mantle boundary. The alternative plate theory is that the mantle source beneath a hotspot is not anomalously hot, rather the crust above is unusually weak or thin, so that lithospheric extension permits the passive rising of melt from shallow depths. Origin The origins of the concept of hotspots lie in the work of J. Tuzo Wilson, who postulated in 1963 that the formation of the Hawaiian Islands resulted from the slow movement of a tecton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fringing Reef
A fringing reef is one of the three main types of coral reef. It is distinguished from the other main types, barrier reefs and atolls, in that it has either an entirely shallow backreef zone (lagoon) or none at all. If a fringing reef grows directly from the shoreline, then the reef flat extends to the beach and there is no backreef. In other cases (e.g., most of the Bahamas), fringing reefs may grow hundreds of yards from shore and contain extensive backreef areas within which it contains food and water, examples are Philippines, Indonesia, Timor-Leste, the western coast of Australia, the Caribbean, East Africa, and Red Sea. Charles Darwin believed that fringing reefs are the first kind of reefs to form around a landmass in a long-term reef growth process.Kennedy, D.M. and Woodroffe, C.D. 2002.Fringing reef growth and morphology: a review. ''Earth-Science Reviews''. 57:255-277. The largest fringing coral reef in the world is the Ningaloo Reef, stretching to around along the coas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Islands In The Pacific Ocean
Collectively called the Pacific Islands, the islands in the Pacific Ocean are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of several different concepts: (1) those countries and islands with common Austronesian origins, (2) the islands once (or currently) colonized, or (3) the geographical region of Oceania. This list of islands in the Pacific Ocean is organized by archipelago or political boundary. In order to keep this list of moderate size, the more complete lists for countries with large numbers of small or uninhabited islands have been hyperlinked. Name ambiguity and groupings The umbrella term ''Pacific Islands'' has taken on several meanings. Sometimes it is used to refer only to the islands defined as lying within Oceania. At other times, it is used to refer to the islands of the Pacific Ocean that were previously colonized by the British, French, Spani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral Island
A coral island is a type of island formed from coral detritus and associated organic material. It occurs in tropical and sub-tropical areas, typically as part of a coral reef which has grown to cover a far larger area under the sea. Ecosystem Coral reefs are some of the oldest ecosystems on the planet, over geological time forming massive reefs of limestone. The reef environment supports more plant and animal species than any other habitat. Coral reefs are vital for life for multiple aspects some of which include structure, ecology, and nutrient cycles which all support biodiversity in the reefs. Coral reefs build massive calcareous skeletons that serve as homes for animals such as fish hiding inside the crooks and crannies of the reef and barnacles attaching themselves directly to the coral’s structure. The structures also help plants that need the sun to photosynthesis, photosynthesize, by lifting the plants to the ocean’s surface where the sunlight can penetrate the wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niue
Niue (, ; niu, Niuē) is an island country in the South Pacific Ocean, northeast of New Zealand. Niue's land area is about and its population, predominantly Polynesian, was about 1,600 in 2016. Niue is located in a triangle between Tonga, Samoa, and the Cook Islands. It is 604 kilometres northeast of Tonga. The island is commonly referred to as "The Rock", which comes from the traditional name "Rock of Polynesia". Niue is one of the world's largest coral islands. The terrain of the island has two noticeable levels. The higher level is made up of a limestone cliff running along the coast, with a plateau in the centre of the island reaching approximately 60 metres (200 feet) above sea level. The lower level is a coastal terrace approximately 0.5 km (0.3 miles) wide and about 25–27 metres (80–90 feet) high, which slopes down and meets the sea in small cliffs. A coral reef surrounds the island, with the only major break in the reef being in the central western c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nauru
Nauru ( or ; na, Naoero), officially the Republic of Nauru ( na, Repubrikin Naoero) and formerly known as Pleasant Island, is an island country and microstate in Oceania, in the Central Pacific. Its nearest neighbour is Banaba Island in Kiribati, about to the east. It further lies northwest of Tuvalu, northeast of Solomon Islands, east-northeast of Papua New Guinea, southeast of the Federated States of Micronesia and south of the Marshall Islands. With only a area, Nauru is the third-smallest country in the world behind Vatican City and Monaco, making it the smallest republic as well as the smallest island nation. Its population of about 10,000 is the world's second-smallest (not including colonies or overseas territories), after Vatican City. Settled by people from Micronesia circa 1000 BCE, Nauru was annexed and claimed as a colony by the German Empire in the late 19th century. After World War I, Nauru became a League of Nations mandate administered by Austra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Makatea
Makatea, or Mangaia-te-vai-tamae, is a raised coral atoll in the northwestern part of the Tuamotus, which is a part of the French overseas collectivity of French Polynesia. It is located southwest from Rangiroa to the west of the Palliser group, which also is in French Polynesia. Makatea is surrounded by spectacular cliffs, rising to a plateau above sea level. This island is long, with a maximum width of in the south. It is in area. Makatea is one of the only four islands of the Tuamotu Archipelago (along with Nukutavake, Tikei, and Tepoto Nord) that do not take the form of a typical atoll. History Makatea is one of the only Paumotuan islands with potable water. Its native name derived from the drinking water being brought out of its dark caves by the local people. "Mā," pure, clear; used here to mean water, "Atea," light of day and "K" for euphony. The other name of the Island was Mangaia-te-vai-tamāe, meaning "Mangaia of the purified (or clear) water." The island w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henderson Island (Pitcairn Islands)
Henderson Island (formerly also San Juan Bautista and Elizabeth Island) is an uninhabited island in the south Pacific Ocean. It is part of the Pitcairn Island Group, together with Pitcairn, Oeno, and Ducie Islands. Measuring , it has an area of and is located northeast of Pitcairn Island. It has poor soil and little fresh water, and is unsuitable for agriculture. There are three beaches on the northern end and the remaining coast comprises steep (mostly undercut) cliffs up to in height. In 1902, it was annexed to the Pitcairn Islands colony, which is now a British Overseas Territory. Henderson is one of the last two raised coral atolls in the world whose ecosystems remain relatively unaffected by human contact, along with Aldabra in the Indian Ocean. In 1988, it was designated a World Heritage Site by the United Nations. Ten of its 51 flowering plants, all four of its land birds and about a third of the identified insects and gastropods are endemic – a remarkable diversi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Islet
An islet is a very small, often unnamed island. Most definitions are not precise, but some suggest that an islet has little or no vegetation and cannot support human habitation. It may be made of rock, sand and/or hard coral; may be permanent or tidal (i.e. surfaced reef or seamount); and may exist in the sea, lakes, rivers or any other sizeable bodies of water. Definition As suggested by its origin ''islette'', an Old French diminutive of "isle", use of the term implies small size, but little attention is given to drawing an upper limit on its applicability. The World Landforms website says, "An islet landform is generally considered to be a rock or small island that has little vegetation and cannot sustain human habitation", and further that size may vary from a few square feet to several square miles, with no specific rule pertaining to size. Other terms * Ait (/eɪt/, like eight) or eyot (/aɪ(ə)t, eɪt/), a small island. It is especially used to refer to river i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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