Is there in the atoll. New explanatory and derivational dictionary of the Russian language, T. F. Efremova. What is an atoll made of?

An atoll is a coral island that partially or completely surrounds a lagoon. Atolls come in a wide variety of shapes, configurations, and sizes. The corals of the atoll crown uplifts at the bottom of the ocean, whether it is the edge of a disappeared seamount or a volcano, which have eroded or partially collapsed under water over time. A lagoon forms over a volcanic crater or caldera while the upper edge remains above water or at shallow depths, allowing corals to grow and form reefs. Since corals grow exclusively in warm seas, atolls are found only in the tropical and subtropical zones of the Earth. For many people, the mesmerizing atolls with vibrant coral reefs and pristine turquoise lagoons seem literally inseparable from the incredible sea ​​adventures and heavenly beach holiday.

10. Funafuti, Tuvalu

Tuvalu is a Pacific state in the western part of Polynesia, which includes 4 islands and 5 atolls scattered over 350 kilometers. "Tuvalu" in translation from local language means "eight standing together" (that's how many inhabited islands in Tuvalu). If you look at the map, the state is located in the middle between Australia and Hawaii, and is probably best known for its ".tv" Internet domain. In terms of population, Tuvalu is the second smallest sovereign state in the world, only the Vatican has fewer inhabitants. Due to the remoteness of the country, there are very few tourists in Tuvalu. The capital of Tuvalu, Funafuti, is a small coral atoll. Its width is about 20 meters in the narrowest part, and about 400 meters in the widest part of the island. The capital has approximately 4,500 inhabitants and is key place. Near the airport there are administrative buildings, a beautiful church and one hotel.

An island is a piece of land that is separated from the mainland by water on all sides. On our planet, you can count about half a million large and crumbs ...

9. Bikini Atoll, Marshall Islands

Bikini Atoll is known for three things: first, in 1946, an open bikini swimsuit for women was named after this atoll; secondly, the events described by Janusz Wisniewski in the novel of the same name took place here; and thirdly, during the Pacific nuclear testing It was here that the United States passed a total of 67 tests over 12 years from 1946 to 1958. The 167 inhabitants of the island were relocated to neighboring safe islands. Today, Bikini Atoll is safe to visit and its background radiation is now less than most major cities, but the soil still contains dangerous levels of radioactive material. Fish are unaffected and are found in abundance here due to the lack of fishermen. Most of the visitors to the atoll are diving enthusiasts who dive to the ships that were sunk during the tests in 1946.

8. Tubbataha Reef, Philippines

Natural Park Tubbataha reef covers an area of ​​130 hectares, including the northern and southern atolls. This is a unique example of an atoll reef with a very high density marine species. north atoll serves as a nesting site for birds and sea ​​turtles. The natural park is a perfect example of a pristine coral reef with a spectacular 100-meter perpendicular wall, extensive lagoons and two coral islands. Tubbataha is in a unique position - in the heart of the Sulu Sea. The reef is home to whales, dolphins, sharks, turtles and Napoleon fish. In total, the reef ecosystem supports over 350 coral species and about 500 fish species. Tubbataha Reef is one of the best places for diving Philippine Islands which is listed world heritage UNESCO.

7. Lighthouse Reef, Belize

Lighthouse Reef is the most offshore of all Belize's atolls. However, it is quite small, with a length of about 80 kilometers. However, it is he who offers the best diving in everything Caribbean. Lighthouse Reef is incredibly popular among other atolls because of the large blue hole with a diameter of 300 meters, which is located near its center. The Great Blue Hole offers divers interesting observations of limestone formations (during ice age a system of limestone caves was formed here, flooded due to the rise in the level of the world ocean), which form its walls. Divers may encounter several interesting views fish, including giant groupers, nurse sharks and several types of reef sharks such as the Caribbean reef shark.

6. Tikehau or Krusenstern Atoll, French Polynesia

Tikehau is located on the northwestern tip of the Tuamotu archipelago. It was discovered by the Russian navigator Otto Kotzebue in 1816. This atoll is almost circular in shape with a maximum diameter of 28 kilometers and consists of two major islands and numerous small islands. Almost the entire territory of the atoll, except for the northeastern part, is inhabited, there are 400 inhabitants (according to the 1996 census), most of whom live in the village of Tuherahera. Tikehau is undeniably a postcard picture, with long stretches of white or pink sandy islands, within which a turquoise lagoon shelters the most amazing variety of fish.

5. Caroline Island, Republic of Kiribati

First seen by Europeans in 1606, then attached to Britain, and finally becoming part of independent republic Kiribati in 1979, Caroline Island became famous for being the first on Earth (outside of Antarctica) to face an attack on January 1, 2000. The island is one of the most pristine tropical islands and one of the most pristine atolls in the world. It is home to one of the world's largest populations of palm thief (a type of crab) and an important nesting site for seabirds, most notably the black tern. However, due to the fact that the highest point of the island is located at a distance of 6 meters from the ocean level, there is real threat its flooding due to global warming and subsequent sea level rise. The Government of Kiribati estimates that this could happen as early as 2025.

There are a huge number of islands in the Mediterranean Sea, numbering in the thousands, and many of them have their own history and mysteries that have not yet been solved by...

4. Aitutaki Atoll, Cook Islands

Aitutaki Atoll consists of several volcanic and coral islands around a triangular lagoon. The whole lagoon and its islands are breathtakingly beautiful. A classic postcard featuring a palm tree bordered by a tropical island with shallow, warm turquoise waters, corals, tropical fish and blue skies. The most popular attraction is Tapuaetai (One Foot Island), a small island in the southeast of the lagoon. In 2006, Aitutaki was the location for the filming of the American television show Lost: The Cook Islands.

3. Aldabra, Seychelles

Located in the Indian Ocean, Aldabra Atoll is an outstanding example of coral atoll. It is one of the largest atolls in the world (only Christmas Island in Kiribati is larger) and contains one of the most important natural environments habitats to study evolutionary and ecological processes. Aldabra Atoll consists of four large coral islands that surround a shallow lagoon; the island group itself is surrounded by a coral reef. Due to the difficulty of access and isolation, Aldabra Atoll has been protected from human influence and thus has preserved about 152,000 giant tortoises, the world's largest population of this reptile. Marine habitats range from coral reefs to seaweeds and mangroves. In 1982, Aldabra Atoll was included in the UNESCO World Heritage List as unique monument nature. In 2015, Czech filmmakers filmed and released to the world distribution a full-length documentary film “Aldabra. Journey to a Mysterious Island” tells about the unique flora and fauna of the island.

2. Rangiroa, French Polynesia

Rangiroa is one of the largest atolls in the world and the largest atoll in the Tuamotu archipelago. The land area of ​​79 km² is a cluster of 415 small islands. Rangiroa is a prime snorkeling destination due to the clear blue waters of the lagoon and the exceptional diversity of marine life. Popular places diving include blue lagoon and the Tiputa Pass. Here you can easily encounter gray reef sharks, rays, manta rays, dolphins, tuna and hammerhead fish.

1. Atolls of the Maldives

The Maldives is a group of islands in the Indian Ocean near India. People Maldives are called Maldivians and his language is known as "Dhivehi". The Maldives is made up of atolls, coral reefs and coral islands that rise slightly above sea level: the most high point archipelago - on the southern Addu Atoll (Siena) - 2.4 m. In total, the state was formed from 26 geographical atolls, which include about 1200 islands, which are divided into 20 administrative units. Not all of the islands are inhabited, in fact there are only about 200 islands. The rest are used for various kinds activities, the most important of which is tourism. The Maldives reef is called one of the wonders of the world in terms of biodiversity marine life and corals. The very word "atoll" originates from the Maldivian word "atholhu".

The Maldives is a unique creation of nature and amazing tourist facility. Located in the Indian Ocean near India, the state is a Muslim republic. At the same time, respect for tourists is so strong that due attention is paid to the main Christian holidays. The Republic of Maldives consists of several atolls, which, in turn, include numerous islands. Only 10 groups of atolls out of 20 are open for tourists to visit. At the same time, almost every hotel in the Maldives occupies a separate island, which gives tourists a sense of peace and serenity. However, for fans active rest there is something to do - there are plenty of opportunities for this on the islands, including diving, for which it is Island state visited by divers from all over the world. For all the exoticism, holidays in the Maldives are distinguished by the highest level of service.

In the material on Tourister.ru we will talk about the structure of the Republic of Maldives - atolls and islands with their description and detailed information. Also you can explore detailed maps of atolls : , , And .

Kaafu Atoll (North Male)

Kaafu Atoll (South Male)

The atoll is separated from North Male by the Vadu Strait and stretches from west to east for 19 km and from north to south for 36 km. Only three islands of the pearl chain are occupied by local natives, the remaining 19 paradise turned into resorts and delight travelers from all over the world with gentle lagoons and marvelous beaches.

South Male is possible.

Vaavu Atoll

Alternative title: Felidhu

Located 65 km from the capital of the Maldives - Male (90 minutes by speedboat or 5 hours by regular boat). The atoll is an interesting geographical phenomenon, as it consists of two atolls: the main Vavu and a round one, 9 kilometers in diameter, located next to the main atoll. Five inhabited islands with a population of about 2,300 people, make Vaavu Atoll the smallest administratively in the Maldives. In addition to these five, there are about 14 other islands, but most of them are almost undeveloped by tourists compared to the islands of other atolls. Vaavu Atoll is considered one of the best diving spots in the Maldives.

The Fotteyo Kandu dive site is considered the best in the country and one of the top five in the world. Vaavu Atoll was opened to tourists in 1975, and has become a favorite with many organizers of various cruises and safaris in the Maldives. The reefs of the eastern side of the atoll are in an untouched state and are perfect for lovers of not only diving, but also snorkeling. There are a lot of sharks here, there is a chance to see hammerhead fish and other equally interesting fish.

Look detailed map atoll and read about tourist islands Wow you can.

Meemu Atoll

Alternative title: Mulaku

The atoll stretches for 50 kilometers from north to south and 30 kilometers wide, containing eight fishing islands and two resorts. There are excellent places for recreation and diving, which is confirmed by numerous cruises.

View a detailed map of the atoll and read about tourist islands Meem can.

Seenu Atoll

Alternative title: Addu

The southernmost atoll, located right at the equator, stretching for 15 km from north to south and 18 km from west to east. It consists of 5 islands: northern Midu and western Hitado, Gan, Feydu and Marado, united by bridges. An airport and a resort hotel are open on the island of Gan, and large Khitadhoo ranks 2nd in terms of population after Male - 12,000 inhabitants. Green and pretty, Feidou and Marado rustle with plantations of coconut palms, nature has endowed them with small bays where fishing villages have settled down. A pleasant surprise awaits the guests of the hotel in Ghana - at any time they can visit the nearby islands and get acquainted with the life of local aborigines.

View a detailed map of the atoll and read about tourist islands Seenu can.

Faafu Atoll

Alternative title: Northern Nilande (Nilandhe Atholhu Uthuruburi)

A small atoll, has an oval shape and the second name is North Nilande. It stretches for 21 km from west to east and 45 km from north to south, containing five fishing islands and only one resort, relatively recently opened to travelers.

View a detailed map of the atoll and read about tourist islands Faafu can.

Dhaalu Atoll

Alternative title: Nilande South (Nilandhe Atholhu Dhekunuburi)

Dhaalu Atoll is located 150 km north of Male and 5 km from Faafu Atoll. It is also known as Nilandhe Atholhu Dhekunuburi (South Nilade Atoll). It is separated from North Nilade (Faafu Atoll) by the Strait of Deburieiterei Kandu. The airport and other atolls can be reached by seaplane or speedboat.

Dhaalu Atoll, 38 km long and 23 km wide, has about 46 islands, many of which are uninhabited. Seaplane transfer takes 40 minutes. For tourism, Dhaalu Atoll was opened quite recently. The islands open to tourists are located in the northern part of the atoll and provide excellent diving opportunities. The main island is Kudahuwadhoo. It's pretty big Island with a developed infrastructure and a population of 1500 people.

The main reefs, interesting and accessible for diving, are located along the northern and northeastern parts of the islands. There are practically no shallow reefs inside the atoll.

Relatively clean from coral thickets, the lagoon allows you to safely go on a tour of the islands on a boat. Dhaalu Atoll still keeps the ruins of ancient monasteries and mosques. On the islands where he lives indigenous people Souvenirs are much cheaper than in the capital.

View a detailed map of the atoll and read about tourist islands Dhaalu is possible.

Alif Atoll

Alternative title: Ari (Ari), also the northern and southern parts are called Alif Alif and Alif Dhaal

The atoll stretches for 33 km from west to east and 96 km from north to south. The atoll is divided into two honors: Alif Alif (northern) and Alif Daal (south). In the northern part, in addition to the main atoll, there is a small Radsu atoll, and in the southern part, the capital Mahibadhoo. The atoll includes 70 islands, but only 18 of them are inhabited, and 25 have been turned into resorts. Once upon a time, local natives hunted sharks and turtles, but since sea hunting is banned, they have been busy servicing tourist hotels.

Baa Atoll

Alternative title: Malosmadulu (Maalhosmadulu Dhekunuburi)

It is an administrative unit of the Republic of Maldives, together with Horseborough Atoll, with the capital Eidafushi. The atoll stretches for 32 km from west to east and 42 km from north to south and includes 10 inhabited islands. Local aboriginals trade fishing, at the same time mastering more profitable tourism professions. Undersea world amazingly varied and surprising interesting places for diving. Marvelous corals, as yet untouched by divers, as well as dozens of fish species await ocean treasure hunters!

Lhaviyani Atoll

Alternative title: Miladunmadulu Uthuruburi

The atoll is 120 km away from the Maldivian capital, and therefore travelers arrive to rest by seaplane. The atoll stretches for 35 km from north to south and 37 km from west to east. Products and goods are brought here on dhoni, sailing such a considerable distance for 8 hours. Fadiffoulou contains 6 fishing and 4 resort islands.

View a detailed map of the atoll and read about tourist islands Lhaviyani is possible.

atolls- coral islands in the form of solid or discontinuous rings surrounding the lagoon. In essence, an atoll is an elevation at the bottom of the ocean, which, as it were, is crowned with a coral superstructure. She, in turn, forms a reef with a group of small islands "motu", which are separated from each other by straits. The straits connect the inner lagoon to the surrounding ocean. If there are no such straits, then the land forms a continuous ring. In this case, the water in the lagoon is often less salty than the ocean. Elevation at the bottom of the ocean usually has a cone shape, formed on the site of an extinct volcano.

Major atolls of the Maldives

North Male Atoll

The city of Male is the capital of the Maldives, located on the main atoll - North Male. It is 69 km long and 39 km wide. This atoll includes 50 rather large islands and several small ones. For tourists, North Male Atoll is attractive for its snow-white beaches, turquoise lagoons and cozy atmosphere.

South Male Atoll

This atoll consists of three dozen islands, and only three of them are inhabited. 10 islands are uninhabited and 17 are hotels. South Male is 36 km long and 19 km wide. The resorts are usually reached by speed boats, and between the nearby islands, movement is carried out using motor boats.

Baa Atoll

Baa Atoll has 10 inhabited and 41 desert island. The atoll is 42 km long and 32 km wide. Basic concept local resort- Modern comfort combined with Robinson Crusoe lifestyle.

Ari and Rasdhoo atolls

Ari Atoll is 33 km long and 96 km wide (from north to south). The atoll is located to the east of Male and includes the large Ari and the small Rasdhoo atolls. Ari has approximately 70 islands. 18 of them are inhabited by people, and 26 are purely tourist area. These are fairly new resorts, the construction of which took place in the 90s. Now the influx of tourists to Ari has reached its peak and resort area is very popular. locals they make sails, collect and process corals, hunt sharks and turtles, from which a special oil is extracted to lubricate local boats.

Dhaalu Atoll

The main island of Dhaalu Atoll is Velavaru. It takes about 40 minutes to reach it by seaplane. The locals used to call it "turtle island". Here reigns lush tropical vegetation, tall palm trees, sandy beaches and an attractive picturesque lagoon. All this attracts to the island turtles ("velaa" - translated from the local language Dvivehi - "turtle") lovers of wildlife.

Laviani Atoll

This atoll is located far north of North Male at a distance of about 120 km from the latter. The Laviani Atoll consists of 63 islands, most of which are concentrated around barrier reef over 30 km. This is one of the best diving spots in the entire Maldives archipelago. Here incredible amount beautiful corals and colorful tropical fish. IN clear waters Laviani Atoll is home to some of the most beautiful creatures in the ocean, including glassfish, moray eels or large nurse sharks.

Addu Atoll

Addu Atoll is located 480 km from the capital of the Maldives, the city of Male and international airport Hulule. This is the southernmost of the elements of the Maldives archipelago, located south of the equator. The island has a well-developed network of communications and roads. The largest island in the atoll is Gan, which is very different from the rest. It is 5 km long and 3 km wide. The island is covered with banana plantations and dense flowering vegetation. Gan is connected by dams to four neighboring islands, only slightly inferior to it in size. You can ride a bike along them, and the entire route will take only 20 km. The most beautiful lake here from October to March it receives a lot of wintering birds, and there are also places on the islands where you can swim.

The content of the article

ATOLL, ring-shaped coral reef surrounding the water area. Coral reefs are common in tropical and subtropical latitudes, most widely in the Pacific and Indian Oceans. The word "atoll" comes from the name used by the peoples of Oceania for the reefs that form a chain small islands, towering 46 m above the water surface. Sometimes reefs are flooded, and between their individual parts there are deep straits. The lake-like waters within the atolls are called lagoons. Usually their depth is 1830 m, but sometimes it reaches 90 m.

Structure.

The main material from which they are built Coral reefs, is a limestone formed as a result of the accumulation of skeletons of marine animals and plants containing calcium carbonate, mainly corals and coralline algae. Islets scattered along reefs usually consist of limestone fragments and crumbs - products of wave activity. Often, small dunes are formed from this material under the influence of wind. The outer coast of most of the atoll islands is a rather narrow strip of fringing reefs, often with an even border of massive pink calcareous algae and steep, narrow beaches composed of limestone fragments. Behind the coastal ridge of the beach, coarse-grained material is replaced by crushed stone, which is further replaced by gravel as it is crushed. In the center of the islet there is often a depression filled with saline soil stained with humus. The interior of the island is usually composed of coarse-grained coral sand or fine gravel, while the central parts of the beach are composed of fine calcareous sand. If the atoll is completely raised above sea level, then the limestones composing it usually erode and form a rough surface “macatea”. The groundwater level is very close there, and small wells are often dug near the center of the islands. If the island is large or there is a lot of rainfall, then the groundwater is almost fresh, but if it is small or located in an area with little rainfall, then the groundwater is brackish or saline.

Flora.

The vegetation cover is the most remarkable characteristic of the surface of the atolls. It is sparse and most often consists of several species of widespread herbaceous plants and tree species that live in the coastal strip. In the distribution of vegetation, a certain zonality is observed in the direction from the outer edge of the atoll to the inner one. She may be in in general terms described for the entire Indo-Pacific region, where atolls are especially numerous, and their flora is of the same type. The outer zone is represented by shrubs, among which scaevola shrubs predominate ( Scaevola frutescens). This is followed by forests, mainly from halophytes such as silver messerschmidia ( Messerschmidia argenta) and pandanus roofing ( Pandanus tectorius). Even farther from the coast, there are fewer halophytes, and cordia appear ( Cordia), pisonia large ( Pisonia grandis), ochrosia ( Ochrosia) and other types. In the center, in more mesophytic conditions, the primary vegetation probably consisted of trees such as splendid coetard ( Guetta speciosa), hibiscus lime-shaped ( Hibiscus tiliacens), ficuses, pisonias, pandanuses, Asian barringtonia ( Barringtonia asiatica), terminals ( Terminalia), etc. On most of the islands, these forests were subsequently replaced by plantations of coconut palms and breadfruit. The inner zone of the beaches is characterized by a narrow strip of trees such as hernandia, calophyllum, pandanus, thespesia, cordia. On sandbars between the islets are usually found suriana maritime ( Suriana maritima) and scaevola, and on the rock outcrops sourish pemphis ( Pemphis acidula). In places, in the inner parts of the islets, waterlogged depressions are found, and in some of them they are confined to hard rocks. In such conditions, some tree species typical of mangrove swamps are found. Other islets are swampy and treeless, dominated by grasses and sedges. On inhabited islands, soil is taken out of these depressions and filled with humus, and then used to grow taro, sugar cane and other plants. Due to the salinity of the soil, few (except those listed above) cultivated plants can grow on low coral islets. Taro, breadfruit and coconuts are the main food of the population, in addition, coconuts are a source of drinking water.

Other natural resources.

The vast majority of the atolls are inhabited, and there, crop production depends on the potential fertility of nutrient-poor saline soils. The main crop is coconuts. Along with the above plants, the basis of the diet of the population is fish and shellfish, which abound in lagoons, reefs and adjacent open water areas. Other trade items are guano, pearls, shells for making buttons and dried holothurians.

The most fertile are the large atolls that rise above sea level, especially if they are confined to very humid areas. They feature much more lush vegetation, richer flora, and a much more diverse array of crops. Apparently, all this is associated with lower soil salinity. On the uplifted atolls, there are often large deposits of phosphorites (probably formed from ancient deposits of guano). Such atolls include the islands of Makatea, Nauru, Ocean, Angaur. The guano deposits on many of the atoll islands have been formed by sea birds such as gannets, frigatebirds, terns and tropical birds that breed here. In addition to the listed birds and land crabs, including the palm thief, the terrestrial fauna is poor: rats dominate, and in the western part Pacific Ocean fruit bats (fruit-eating bats) are numerous. The waters abound with turtles, spiny lobsters, giant bivalves, and many kinds of fish. The rich fauna of the reefs includes many species of invertebrates.

famous atolls.

The largest groups of atolls in the Indian Ocean are the Maldives and Laccadives; in the Pacific Ocean Caroline, Marshall, Gilbert Islands in Micronesia, Tuamotu and others in Polynesia; a large number of atolls scattered throughout Melanesia. IN Atlantic Ocean there are several atolls in the Lesser Antilles group, in addition, the Bahamas include a number of atolls that are not typical. The largest atoll in terms of area (with a relatively small lagoon in the center) is Christmas Island in the equatorial Pacific Ocean. The largest lagoon is apparently located on Kwajalein Atoll (Marshall Islands), although lagoons of almost the same size are found on some other atolls. see also CORAL REEFS.

Atoll

Atoll

coral building in the form of a solid or broken ring, bordering the water basin - lagoon. The atoll ring is formed by separate islands. Some of them have their own lagoon or represent an incomplete ring that opens towards the main lagoon with a wide channel. They are found only in the tropical zone. The atolls can vary in size, are usually small, but some are up to 50 km across. The underwater base of the atoll is usually the heights of the oceanic bed. volcanic origin. The genesis of the atoll, according to the hypothesis of Charles Darwin, is associated with the slow sinking of a tropical island surrounded by a ring of barrier coral reef, which is gradually built up by buildings of colonial corals. According to another concept, the formation of atolls occurs due to a rise in the level of the World Ocean as a result of the melting of ice sheets, and not the sinking of the bottom, as evidenced, in his opinion, by the same depths from which coral structures begin in different atolls. Atolls are very demanding on the complex natural conditions: the temperature of air and water, the constancy of salinity and dynamics of ocean waters, their purity, etc. They are found mainly in the waters of the Pacific and Indian Oceans.

Plan and vertical section of the atoll (along the line AB)

Geography. Modern illustrated encyclopedia. - M.: Rosman. Under the editorship of prof. A. P. Gorkina. 2006 .

Atoll

ring-shaped coral reef surrounding the water area. Coral reefs are common in tropical and subtropical latitudes, and most widely in the Pacific and Indian Oceans. The word "atoll" comes from the name used by the peoples of Oceania for reefs that form a chain of small islands, rising 4-6 m above the surface of the water. Sometimes reefs are flooded, and between their individual parts there are deep straits. The lake-like waters within the atolls are called lagoons. Usually their depth is 18–30 m, but sometimes it reaches 90 m.
Structure. The main material from which coral reefs are built is limestone, formed as a result of the accumulation of skeletons of marine animals and plants containing calcium carbonate, mainly corals and coralline algae. Islets scattered along reefs usually consist of limestone fragments and crumbs - products of wave activity. Often, small dunes are formed from this material under the influence of wind. The outer coast of most of the atoll islands is a rather narrow strip of fringing reefs, often with an even border of massive pink calcareous algae and steep, narrow beaches composed of limestone fragments. Behind the coastal ridge of the beach, coarse-grained material is replaced by crushed stone, which is further replaced by gravel as it is crushed. In the center of the islet there is often a depression filled with saline soil stained with humus. The interior of the island is usually composed of coarse coral sand or fine gravel, while the central parts of the beach are composed of fine calcareous sand. If the atoll is completely raised above sea level, then the limestones composing it usually erode and form a rough surface - “macatea”. The groundwater level is very close there, and small wells are often dug near the center of the islands. If the island is large or there is a lot of rainfall, then the groundwater is almost fresh, but if it is small or located in an area with little rainfall, then the groundwater is brackish or saline.
Flora. The vegetation cover is the most remarkable characteristic of the surface of the atolls. It is sparse and most often consists of several species of widespread herbaceous plants and tree species that live in the coastal strip. In the distribution of vegetation, a certain zonality is observed in the direction from the outer edge of the atoll to the inner one. It can be described in general terms for the entire Indo-Pacific region, where atolls are especially numerous and their flora is of the same type. The outer zone is represented by shrubs, among which scaevola shrubs predominate ( Scaevola frutescens). This is followed by forests, mainly from halophytes such as silver messerschmidia ( Messerschmidia argenta) and pandanus roofing ( Pandanus tectorius). Even farther from the coast, there are fewer halophytes, and cordia appear ( Cordia), pisonia large ( Pisonia grandis), ochrosia ( Ochrosia) and other types. In the center, in more mesophytic conditions, the primary vegetation probably consisted of trees such as splendid coetard ( Guetta speciosa), hibiscus lime-shaped ( Hibiscus tiliacens), ficuses, pisonias, pandanuses, Asian barringtonia ( Barringtonia asiatica), terminals ( Terminalia), etc. On most of the islands, these forests were subsequently replaced by plantations of coconut palms and breadfruit. The inner zone of the beaches is characterized by a narrow strip of trees such as hernandia, calophyllum, pandanus, thespesia, cordia. On the sandy spits between the islets, the seaside suriana is usually found ( Suriana maritima) and scaevola, and on rock outcrops - sour pemphis ( Pemphis acidula). In places, in the inner parts of the islets, waterlogged depressions are found, and in some of them they are confined to hard rocks. In such conditions, some tree species typical of mangrove swamps are found. Other islets are swampy and treeless, dominated by grasses and sedges. On inhabited islands, soil is taken out of these depressions and filled with humus, and then used to grow taro, sugar cane and other plants. Due to the salinity of the soil, few (except those listed above) cultivated plants can grow on low coral islands. Taro, breadfruit and coconuts are the main food of the population, in addition, coconuts are a source of drinking water.
Other natural resources. The vast majority of the atolls are inhabited, and there, crop production depends on the potential fertility of nutrient-poor saline soils. The main crop is coconuts. Along with the above plants, the basis of the diet of the population is fish and shellfish, which abound in lagoons, reefs and adjacent open water areas. Other trade items are guano, pearls, shells for making buttons and dried holothurians.
The most fertile are the large atolls that rise above sea level, especially if they are confined to very humid areas. They feature much more lush vegetation, richer flora, and a much more diverse array of crops. Apparently, all this is associated with lower soil salinity. On the uplifted atolls, there are often large deposits of phosphorites (probably formed from ancient deposits of guano). Such atolls include the islands of Makatea, Nauru, Ocean, Angaur. Guano deposits on many atoll islands were formed as a result of the life of sea birds - gannets, frigatebirds, terns and tropical birds that breed here. In addition to the listed birds and land crabs, including the palm thief, the terrestrial fauna is poor: rats dominate, and fruit bats (fruit-eating bats) are numerous in the western Pacific Ocean. The waters abound with turtles, spiny lobsters, giant bivalves, and many kinds of fish. The rich fauna of the reefs includes many species of invertebrates.
famous atolls. The largest groups of atolls in the Indian Ocean are the Maldives and Laccadives; in the Pacific Ocean - the Caroline, Marshall, Gilbert Islands in Micronesia, Tuamotu and others in Polynesia; a large number of atolls are scattered throughout Melanesia. In the Atlantic Ocean there are several atolls in the Lesser Antilles group, in addition, the Bahamas include a number of atolls. The largest atoll in terms of area (with a relatively small lagoon in the center) is Christmas Island in the equatorial Pacific Ocean. The largest lagoon is apparently located on Kwajalein Atoll (Marshall Islands), although lagoons of almost the same size are found on some other atolls. see also Coral reefs .
LITERATURE
Ravikovich A.I. Modern and fossil reefs. M., 1954
Geography of the atolls of the Southwest Pacific. M., 1973

Encyclopedia Around the World. 2008 .

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Modern Encyclopedia

- (Atoll) lagoon reef, a special kind of island. A ring-shaped strip of land surrounding an inland shallow lake or lagoon. Usually A. rises above sea level by several meters. The depth in the lagoon is small; 60 150 m (30 80 sea fathoms), while ... ... Marine Dictionary

Coral island, reef Dictionary of Russian synonyms. atoll n., number of synonyms: 9 bikinis (5) ... Synonym dictionary

atoll- a, m. atoll m., eng. Coral island. Atolian oh, oh. Sometimes the tentacles of an octopus were pushed into the hole, which, apparently, methodically ransacked the atoll jar. A. Kim Fish Simplicitas. // NM 1997 4 102. Lex. Dal: atol; Toll 1863: atoll; SAN 1891 ... Historical Dictionary of Gallicisms of the Russian Language

Atoll- (from the Malay adol closed), a coral building with a shallow lagoon in the middle, connected to the ocean through one or more straits. The base of an atoll is usually the summit. underwater volcano. Distributed in tropical latitudes ... ... Illustrated Encyclopedic Dictionary

A coral structure, in the form of a solid or broken ring, surrounding a shallow lagoon. The base of an atoll is usually the summit of an underwater volcano. Widespread in the tropical latitudes of the Pacific and Indian Oceans ... Big Encyclopedic Dictionary

ATOLL, a ring-shaped CORAL REEF surrounding a shallow LAGOON. The reef appears initially as a frame for an island slowly sinking into the water, usually of volcanic origin. As the island sinks, the coral continues to grow... Scientific and technical encyclopedic dictionary