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Atolls
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 barrier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atolls Of The Maldives
The Maldive Islands are formed by 20 natural atolls, along with a few islands and isolated reefs today which form a pattern stretching from 7 degrees 10′ North to 0 degrees 45′ South. The largest of these atolls is Boduthiladhunmathi, while the atoll containing the most islands is Huvadhu. Some atolls are in the form of a number of islands by time and in the form of isolated reefs, which could be classified as smaller atoll formations. All land above the surface in the Maldives is of coralline origin. The atolls of the Maldives form a quite regular chain and, especially in the northern and central atolls, an arrayed structure is apparent. There are broad and deep channels between some atolls. The origin of the word "atoll" itself is in the language of the Maldives. "Atoll" (from ) is now used in many languages worldwide. Traditionally, Maldivians call the atolls ending in '-madulu' or '-mathi' by their name without adding the word "Atoll" at the end. For example, it is co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marshall Islands
The Marshall Islands, officially the Republic of the Marshall Islands, is an island country west of the International Date Line and north of the equator in the Micronesia region of the Northwestern Pacific Ocean. The territory consists of 29 coral atolls and five main islands as well as 1,220 other very small ones, divided across two Archipelago, island chains: Ratak in the east and Ralik in the west. 97.87% of its territory is water, the largest proportion of water to land of any sovereign state. The country shares Maritime boundary, maritime boundaries with Wake Island to the north, Kiribati to the southeast, Nauru to the south, and the Federated States of Micronesia to the west. The capital city, capital and largest city is Majuro, home to approximately half of the country's population. The Marshall Islands are one of only four atoll based nations in the entire world. Austronesian settlers reached the Marshall Islands as early as the 2nd millennium BC and introduced Southeas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokelau
Tokelau (; ; known previously as the Union Islands, and, until 1976, known officially as the Tokelau Islands) is a dependent territory of New Zealand in the southern Pacific Ocean. It consists of three tropical coral atolls: Atafu, Nukunonu, and Fakaofo. They have a combined land area of . In addition to these three, Swains Island (), which forms part of the same archipelago, is the subject of an ongoing territorial dispute; it is currently administered by the United States as part of American Samoa. Tokelau lies north of the Samoan Islands, east of Tuvalu, south of the Phoenix Islands, southwest of the more distant Line Islands, and northwest of the Cook Islands. Tokelau has a population of approximately 1,500 people; it has the List of countries and dependencies by population#Sovereign states and dependencies by population, fourth-smallest population of any sovereign state or dependency in the world. As of the 2016 census, around 45% of its residents List of sovereign states a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiribati
Kiribati, officially the Republic of Kiribati, is an island country in the Micronesia subregion of Oceania in the central Pacific Ocean. Its permanent population is over 119,000 as of the 2020 census, and more than half live on Tarawa. The state comprises list of islands of Kiribati, 32 atolls and one remote raised coral atoll, raised coral island, Banaba. Its total land area is dispersed over of ocean. The islands' spread straddles the equator and the 180th meridian. The International Date Line goes around Kiribati and swings far to the east, almost reaching 150th meridian west, 150°W. This brings Kiribati's easternmost islands, the southern Line Islands south of Hawaii, into the same day as the Gilbert Islands and places them in the most advanced time zone on Earth: UTC+14:00, UTC+14. Kiribati gained its independence from the United Kingdom, becoming a sovereign state in 1979. The capital, South Tarawa, now the most populated area, consists of a number of islets, connect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuvalu
Tuvalu ( ) is an island country in the Polynesian subregion of Oceania in the Pacific Ocean, about midway between Hawaii and Australia. It lies east-northeast of the Santa Cruz Islands (which belong to the Solomon Islands), northeast of Vanuatu, southeast of Nauru, south of Kiribati, west of Tokelau, northwest of Samoa and Wallis and Futuna, and north of Fiji. Tuvalu is composed of three reef islands and six atolls spread out between the latitude of 5th parallel south, 5° and 10th parallel south, 10° south and between the longitude of 176th meridian east, 176° and 180th meridian, 180°. They lie west of the International Date Line. The 2022 census determined that Tuvalu had a population of 10,643, making it List of countries and dependencies by population, the second-least populous country in the world, behind Vatican City. Tuvalu's total land area is . The first inhabitants of Tuvalu were Polynesians arriving as part of the History of the Polynesian people, migration of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrier Reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Coral belongs to the class Anthozoa in the animal phylum Cnidaria, which includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Coral reefs first appeared 485 million years ago, at the dawn of the Early Ordovician, displacing the microbial and sponge reefs of the Cambrian. Sometimes called ''rainforests of the sea'', shallow coral reefs form some of Earth's most diverse ecosystems. They occupy less than 0.1% of the world's ocean area, about half the area of France, yet they provide a home for at least 25% of all marine species, including fish, mollusks, worms, crustaceans, echinoderms, sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maldives
The Maldives, officially the Republic of Maldives, and historically known as the Maldive Islands, is an Archipelagic state, archipelagic country in South Asia located in the Indian Ocean. The Maldives is southwest of Sri Lanka and India, about from the Asian continent's mainland. The Maldives' chain of Atolls of the Maldives, 26 atolls stretches across the equator from Atolls of the Maldives#Ihavandhippolhu, Ihavandhippolhu Atoll in the north to Addu Atoll in the south. The Maldives is the smallest List of sovereign states and dependent territories in Asia, country in Asia. Its land area is only , but this is spread over roughly of the sea, making it one of the world's most spatially dispersed sovereign states. With a population of 515,132 in the 2022 census, it is the second List of Asian countries by population, least populous country in Asia and the List of countries and dependencies by area, ninth-smallest country by area, but also one of the List of countries and depend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Structure And Distribution Of Coral Reefs
''The Structure and Distribution of Coral Reefs, Being the first part of the geology of the voyage of the Beagle, under the command of Capt. Fitzroy, R.N. during the years 1832 to 1836'', was published in 1842 as Charles Darwin's first monograph, and set out his theory of the formation of coral reefs and atolls. He conceived of the idea during the second voyage of HMS Beagle, voyage of the ''Beagle'' while still in South America, before he had seen a coral island, and wrote it out as HMS Beagle, HMS ''Beagle'' crossed the Pacific Ocean, completing his draft by November 1835. At the time there was great scientific interest in the way that coral reefs formed, and Captain Robert FitzRoy's orders from the British Admiralty, Admiralty included the investigation of an atoll as an important scientific aim of the voyage. FitzRoy chose to survey the Cocos (Keeling) Islands, Keeling Islands in the Indian Ocean. The results supported Darwin's theory that the various types of coral reefs an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chagos Archipelago
The Chagos Archipelago (, ) or Chagos Islands (formerly , and later the Oil Islands) is a group of seven atolls comprising more than 60 islands in the Indian Ocean about south of the Maldives archipelago. This chain of islands is the southernmost archipelago of the Chagos–Laccadive Ridge, a long submarine mountain range in the Indian Ocean. In its north are the Salomon Islands, Nelsons Island and Peros Banhos; towards its south-west are the Three Brothers, Chagos, Three Brothers, Eagle Islands, Egmont Islands and Danger Island, Great Chagos Bank, Danger Island; southeast of these is Diego Garcia, by far the largest island. All are low-lying atolls, save for a few extremely small instances, set around lagoons. From 1715 to 1810, the Chagos Islands were part of France's List of French possessions and colonies, Indian Ocean possessions, administered through Isle de France (Mauritius), Isle de Francewhich was a French colonial empire, colony of France (later renamed as Mauritius). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuamotu Islands
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] |
Maldivian Language
Maldivian, also known by its Endonym and exonym, endonym Dhivehi (, ''Dhivēhī'', ), is an Indo-Aryan languages, Indo-Aryan language belonging to the Indo-Iranian languages, Indo-Iranian branch of the Indo-European languages, Indo-European language family, primarily spoken by the Maldivians, Maldivian people native to the South Asian archipelagic state of the Maldives; as well as the neighbouring Minicoy, Minicoy Island within Lakshadweep, a union territory of India. The Maldivian language has four notable dialects. The standard dialect is that of the capital city of Malé. The greatest dialectal variation exists in the southern atolls of Huvadhu Atoll, Huvadhu, Addu Atoll, Addu and Fuvahmulah. Each of these atolls has its own distinct dialect often thought to be interconnected with each other while being widely different from the dialect spoken in the northern atolls. The southern dialects are so distinct that those only speaking northern dialects cannot understand them. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral Sea Islands
The Coral Sea Islands Territory is an States and territories of Australia#External territories, external territory of Australia which comprises a group of small and mostly uninhabited tropical islands and reefs in the Coral Sea, north-east of Queensland, Australia. The only inhabited island is Willis Island. The territory covers , most of which is ocean, extending east and south from the outer edge of the Great Barrier Reef and includes Heralds Beacon Island, Osprey Reef, the Willis Group and fifteen other reef/island groups. Cato Reef#Cato Island, Cato Island is the highest point in the Territory.Geoscience AustraliaCoral Sea Islands History and status The Coral Sea Islands were first charted in 1803. In the 1870s and 1880s the islands were mined for guano but the absence of a reliable supply of fresh water prevented long-term habitation. The Coral Sea Islands became an Australian external territory in 1969 by the ''Coral Sea Islands Act'' and extended in 1997 to include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
