Our planet is luxurious in all respects: a huge variety of vegetation, the inconspicuous wealth of the animal world and the infinite abundance of the aquatic inhabitants. All this and much more is found on our most beautiful land.
Surely everyone knows that there are four immense ocean on our planet. They all are great in their own way. Quiet, for example, the largest, Atlantic - salty, northern ice-cold - cold, and Indian is the most warm. Here we are the last and devote our article.
Do you know that the Indian Ocean is considered the third largest? Its area is no little, 76.17 million km, and this is 20% of the whole globe. So what secrets keep our mysterious hero? Let's discern below.
General information about the location
In the north, the ocean is washed by mysterious Asia, in the east - adventurous Australia, in the West - Sunny Africa, and in the south - frosty Antarctica. At 30, the highest point of the Indian Ocean is located 30 on the northern Meridian. She is in the Persian Gulf. On 20 about the Meridian of Eastern Longitude, the border with the Atlantic Ocean passes, with a quiet - at 146 o 55 of the same longitude. The length of the Indian Ocean is 100,000 km.
A few words about history
Some areas of ancient civilizations were located on the shores of our hero. Researchers argue that one of the very first shipping was carried out on the waters of the Indian Ocean, about 6 thousand years ago. Described in detail the ocean route Arab sailors. The first geographically information appeared in the 90s of the 15th century, while during the lifetime of Vasco de Gama himself, the first in the history of overcoming the path from Europe to India. It was he who spoke about the intelligent water beauties, which provided the Indian Ocean.
The depth of the ocean was first measured by the world famous to the world's famous Sea James Cup, famous for its round-the-world expeditions and numerous discoveries in the field of geography. To study the ocean in all respects began in the XIX century members of one of the famous English expeditions, furring endless expanses on the famous Chellenger ship.
What countries is the indian ocean?
This giant is washes a huge number of states, both both mainland and island.
Mainland countries of the Indian Ocean:
Australia;
Thailand;
Saudi Arabia;
Indonesia;
Pakistan;
Malaysia;
Mozambique;
Bangladesh;
Island countries of the Indian Ocean:
Mauritius;
Maldives;
Sri Lanka;
Madagascar;
Seychelles.
Here is such an immense Indian Ocean.
Depth of the ocean
The Indian Ocean has five seas in its composition. It is they who form the depth and the area of \u200b\u200bour hero. So, for example, the Arabian Sea is one of the deepest in the Indian Ocean. The significant point is located on the middle-ocean ridge, in its center where the rift valley is located. The depth above it is no little, but 3600 m. The deepest point of the Indian Ocean is located near the island of Java, in Yavanskaya Vpadina, and is 7455 m. Unlike the Pacific Ocean, it is not enough, because its maximum depth is 11022 m. Mariana Trench).
The climate of the Indian Ocean
Most of the ocean lies in tropical, equatorial and subequatorial belts, only the southern area is in high latitudes.
The climate is monsoons and seasonal winds in the northern part of the ocean. There are two seasons in this area: warm, calm winter and roast, rainy, cloudy, storm summer. Southeast Passat is closer to the south. In moderate latitudes, strong Western wind constantly dominates. The maximum amount of precipitation is observed in (about 3000 mm per year). The minimum - off the coast of the Red Sea, Arabia, in the Persian Gulf.
Salinity
The maximum values \u200b\u200bof the salinity of the surface waters of the Indian Ocean - in the Red Sea and the Persian Gulf (41%). Also a fairly high saline coefficient is also observed in the territory of the southern tropics in the eastern part. As it moves towards the Bengal Bay, the indicators are significantly reduced - up to 34%.
It largely depends on the increase in the salt ratio from precipitation and evaporation.
The minimum indicators are characteristic of the territory of Antarctic Waters. As a rule, such a coefficient in this area affects the melting of glaciers.
Temperature
The temperature of the Indian Ocean on the surface of the water is +29 o C. This is the highest indicator. Less is less observed in the African coast, where the Somali course is running - + 22-23 o C. At the equator, the temperature of the surface waters on average is + 26-28 o C. If you move south, it reaches -1 o C (off the coast of Antarctica).
Icebergs are introduced into temperature changes to the temperature changes, which in rare cases swim into the territory of southern latitudes.
As can be seen, the average temperature of the Indian Ocean is generally high, which is why our hero and awarded the title "The Most Warm Ocean in the World".
Buli
The Indian Ocean has 19 bays (3 of them belong to the Red Sea):
The Bay of the Indian Ocean of the Red Sea
- Aqaba. In recent years, has acquired a resort value. Length - 175 km, width - 29 km. West Bank belongs to Egypt, East - Saudi Arabia, North - Jordan and Israel.
- Makadi. Attracts tourists with their amazing coral shores. It is a bay, stretched 30 km along the coast of the Red Sea.
- Separates the Asian Sinai Peninsula from Africa. Length - 290 km, width - 55 km.
Relief
The relief of the Indian Ocean is characterized by the presence at its depth of the ridge called the Indian central ridge. It stretches along the western coast of Industan. On average, the depth above it is 3.5 km. In some places it decreases and is already about 2.4 km. After that, the ridge branches. The first branch goes towards the east and comes to the territory of the Pacific Ocean, almost tasty Antarctica, and ends at the Australia-Antarctic raising, the depth over which is 3.5 km.
Another branch goes to Antarctica to the south and ends with a ridge called Caragelen-Gausberg, the minimum depth on which is 0.5 km, the maximum is 2.3 km.
The central Indian ridge divides the ocean into two different parts of the part: Western and East. On the territory of East is the Indian-Australian and South Australian brand, depths of which vary from 500 to 7455 m. In the northeastern part of the Indian-Australian brand, there is the deepest Wpadin, which has the Indian Ocean. The depth of the ocean, more precisely, its maximum point is located near (7455 m).
The bottom of the Indian Ocean in the western embossed part is significantly different from the East, it is more difficult in its structure. This is due to the fact that in the latter, a significant increase in the bottom is carried out (due to this, in most cases, small in size) and the uneven arrangement of Kotlovin are formed.
The north of Madagascar island is located a hollow called Somali, the depth over which is 5.2 km. The south of the island is the plateau called the Creez, surrounded by all the sides of the basins. The depth above it is 2.5 km. If you move to the northeast, the Central Indian Cas` The depth above it is 5.5 km. Between Madagascar and Cryau, a little to the north, there is a basin called Madagascar with a depth of 5.78 km. South - a hollow, belonging to the cape of needle, the depth over which is 5.5 km. The relief of the Indian Ocean in the direction of Antarctic is characterized by the presence of omission of the bottom. The depth above this area reaches 5.8 km.
Flora and fauna
The nature of the Indian Ocean is diverse and very interesting. Animals and plants are inhabited here, which are accustomed to regular droughts and floods.
Many tropical shores of the Indian Ocean are represented by mangrove thickets, numerous varieties of crabs in this area live from animal rhizophors. The fish entitled or the jumper inhabits the entire territory of the Mangroen region of the Indian Ocean.
Corals with fish living on them and numerous invertebrates died in shallow territories of tropical waters.
In moderate zones, brown, blue-green and most of them represent laminaries, microcustics and fukusy. Among phytoplankton dominates diatoms, and in tropical zones - Peridineia.
The most famous cancers that are more prevailing in the Indian Ocean are cappeats. Now they have more than 20 thousand species. In second place among animals inhabiting this ocean, there are jellyfish and squid. Among the fish are tuna, sailboats, corneters and bright anchovies.
In love with the territory of the ocean and dangerous species of animals. Sharks, crocodiles and poisonous snakes regularly suggest fear of local residents.
Dolphins, whales, dugini and sea seals predominate from mammals in the Indian Ocean. Birds - Penguins, Albatrosse and Frigates.
Pool
The indian ocean pool is rather diverse. It includes African Rivers - Zambezi and Limpopo; The largest Asian rivers - Iruvadi, Salouin; Euphrates and Tiger, which merge among themselves just above the adaptation to the Persian Bay; Ind to be in the Arabian Sea.
Fishing and sea fishing
The coastal population is engaged in economic activity for quite a long time. To this day, fishing and seafood fish is of great importance for the farms of many countries that wash the Indian Ocean. The depth of the ocean provides rich gifts to people, for example, in Sri Lanka, in the north-west of Australia and in the Bahrain Islands there are intensive mining of pearl and pearls.
Near Antarctica, people are actively engaged in whale fishery, and tuna fishing is carried out next to the equator.
In the Persian Gulf there are rich sources of oil, and both on the coastal territory and under water.
Environmental Problems of the Indian Ocean
Human activity led to terrifying consequences. The ocean water has become significantly polluted, which gradually leads to the extinction of certain types of marine inhabitants. For example, several varieties of whale at the end of the 20th century were under threat of complete extinction. The number of sowing and coushlots has greatly decreased.
In the 80s of the 20th century, a complete ban on the hunt for them was introduced by the Whale Fishery Commission. Violation of the moratorium strictly punishable by law. But in 2010, under the influence of countries such as Japan, Denmark, Iceland, ban, unfortunately, were canceled.
A big danger to the marine inhabitants is the pollution of ocean water with petroleum products, all sorts of waste of the nuclear industry and severe metals. Also, through the ocean, there are ways of oil industry, which deliver oil from the Persian Gulf to European countries. If an accident suddenly occurs on such transport, it will lead to the mass death of submarine residents.
It is quite interesting to study geography, especially if it comes to sea beauty and inhabitants. The indian ocean grade 7 is studied in detail. Children enthusiastically listen to everything that teacher tells about this beautiful and mysterious giant, which is sisit of the variety of vegetation and the richness of the animal world.
The Indian Ocean, the third largest ocean on Earth (after the quiet and atlantic), part of the world's ocean. Located between Africa in the North-West, Asia in the north, Australia in the East and Antarctica in the south.
Physico-geographical essay
General. The border of the Indian Ocean in the West (with the Atlantic Ocean South Africa) is carried out according to the Meridian of the Cape Needle (20 ° East longitude) to the coast of Antarctica (the Land of the Queen Mod), in the East (with the South Australian South of Australia) - on the eastern border of the Bassum Strait to the island of Tasmania , and then on the meridian of 146 ° 55 'Eastern longitude to Antarctica, in the northeast (with the Pacific Pacific) - between the Andaman Sea and the Malaccian Strait, further along the southwestern shores of the island of Sumatra, the Sunda Strait, the southern shore of Java Island, South The borders of the seas of Bali and Sava, the northern border of the Arafur Sea, the southwestern shores of New Guinea and the western border of Torresov Strait. The Southern High Specific Part of the Indian Ocean is sometimes relating to the Southern Ocean, which combines the Antarctic sectors of the Atlantic, Indian and Pacific Oceans. However, such a geographical nomenclature is not generally recognized, and, as a rule, the Indian Ocean is considered in its usual borders. The Indian Ocean is the only ocean that is located mostly in the southern hemisphere and is limited in the north with a powerful sushi massif. Unlike other oceans, its mid-ocean ridges form three branches, diverting in different directions from the central part of the ocean.
Indian Ocean Square with seas, bays and straits 76.17 million km 2, water volume 282.65 million km 3, the average depth of 3711 m (2nd place after the Pacific); Without them - 64.49 million km 2, 255.81 million km 3, 3967 m. The greatest depth in the deep-sea zonda referee is 7729 m at point 11 ° 10 'southern latitude and 114 ° 57' East longitude. The shelf area of \u200b\u200bthe ocean (the depth of it is up to 200 m) takes 6.1% of its area, the mainland slope (from 200 to 3000 m) of 17.1%, the bed (over 3000 m) is 76.8%. See map.
Seas. Seas, bays and straits on the water area of \u200b\u200bthe Indian Ocean are almost three times less than in the Atlantic or in the Pacific, they are mostly focused in its northern part. Tropical Zone: Mediterranean - Red; Painted - Arabian, Lakkadivskoye, Andaman, Timor, Arafur; Antarctic zone: Outlook - Davis, Durville, Cosmonauts, Riser-Larsen, Commonwealth (see separate articles about the seas). The largest bays: Bengali, Persian, Adenian, Omansky, Big Australian, Carpenteries, Pruds. Straits: Mozambique, Babel-Mandsheskiy, Bassol, Ormuz, Malakksky, Polkiy, Tenth degrees, Great Channel.
Islands. Unlike other oceans, the islands are few. The total area of \u200b\u200babout 2 million km 2. The largest islands of mainland - Socotra, Sri Lanka, Madagascar, Tasmania, Sumatra, Java, Timor. Volcanic Islands: Reunion, Mauritius, Prince Eduard, Cryau, Kergelen et al.; Coral - Lakkadiv, Maldives, Amilant, Chagos, Nicobar, Most Andaman, Seychelles; Coral Comor, Mascaren, Coconut and Other Islands rises on volcanic cones.
Shores. The Indian Ocean is distinguished by the relatively small rug of coastline with the exception of the northern and northeastern parts, where most seas and major bays are located; comfortable coves little. Africa's shores in the western part of the ocean are apparent, dissected weakly, often surrounded by coral reefs; In the northwestern part - indigenous. In the north, low underdeveloped shores with lagunies and sand bars are dominated, in places with mangroves, originated by the sushi coastal lowlands (Malabar Coast, Koromandel Coast), also distributed abrasion-accumulative (Concan's coast) and delta shores. In the east of the coast, the indigenous, in Antarctica is covered with glaciers descending to the sea, ending ice cloths in a few tens of meters.
Relief bottom. In the embodiments of the Indian Ocean, four main elements of geotexture are distinguished: submarine outlook of the mainland (including the shelf and mainland), transition zones, or island arc zones, ocean bed and mid-oceanic ridges. The area of \u200b\u200bunderwater pains of continents in the Indian Ocean is 17660 thousand km 2. Submarine in Africa is distinguished by a narrow shelf (from 2 to 40 km), its land is located at a depth of 200-300 m. Only near the southern tip of the mainland, the shelf significantly expands and in the area of \u200b\u200bPlateau Agullas stretches to 250 km from the coast. Significant shelf areas are busy coral buildings. The transition from the shelf to the mainland slope is expressed by a clear gentle of the bottom surface and the rapid increase in its inclination to 10-15 °. The underwater outskirts of Asia near the coast of the Arabian Peninsula also has a narrow shelf, gradually expanding on the Malabar coast of Industan and off the coast of the Bangale Bay, while the depth on its outer boundary increases from 100 to 500 m. The mainland slope is clearly traced through characteristic dupin slopes (height to 4200 m, Sri Lanka Island). The shelf and the mainland slope in some areas are cut by several narrow and deep canyons, the most pronounced canyons, which are underwater continuation of the River Gang River (together with the Brahmaputra river, annually takes about 1,200 million tons of suspended and inlets, formed a layer of precipitation over 3500 m thick ) and ind. Underwater outskirts of Australia is distinguished by an extensive shelf, especially in the northern and northwestern parts; In the Bay of Carpenaria and the Arafur sea wide up to 900 km; The greatest depth of 500 m. The mainland slope to the west of Australia is complicated by underwater ledges and separate underwater plateau (the highest height of 3600 m, the island of Aru). On the underwater edge of Antarctica everywhere traces of the influence of the ice load of a huge glacier covering the mainland. Shelf here refers to a special glacial type. The external border almost coincides with the exhaust 500 m. Shelf width from 35 to 250 km. The mainland slope is complicated by longitudinal and transverse ridges, separate ridges, valleys and deep gutters. At the foot of the mainland slope, an accumulative loop is almost universally observed, isolated from the terrigenous material brought by glaciers. The largest biases of the bottom are noted in the upper part, with an increase in the depth of the slope gradually polled.
The transition zone on the day of the Indian Ocean is distinguished only in the area adjacent to the arc of the Sunda Islands, and is the southeast part of the Indonesian transition region. It includes: the basin of the Andaman Sea, the island arc of the Sunda Islands and deep-water gutter. The most morphologically expressed in this zone is a deep-water zondiy flavor with a steepness slopes of 30 ° and more. Comparatively small deep-sea gutters are allocated to the southeast of Timor's island and east of Kai islands, but due to the powerful sedimentary layer, their maximum depths are relatively small - 3310 m (Timor and 3680 m (Kai flavored). The transition zone is extremely seismically active.
The average and oceanic ridges of the Indian Ocean form three underwater mountain ridges, divergent from the area with the coordinates of 22 ° of southern latitude and 68 ° of Eastern longitude to the north-west, south-west and southeast. Each of the three branches is divided into morphological signs of two independent ridges: the North-West - to the Mid-Adensky Ridge and the Arabian-Indian Ridge, South-West - to the West Indian Ridge and the African Antarctic Range, Southeast - on Central Indian ridge and Australo Antarctic raising. Thus, the median ridges are separated by the Lodge of the Indian Ocean into three large sectors. The median ridges are fragmented by transform faults into separate blocks of extensive raising with a total length of over 16 thousand km, the foot of which are located at depths of about 5000-3500 m. The relative height of the ridges is 4700-2000 m, the width is 500-800 km, the depth of rift valleys to 2300 m .
In each of the three sectors of the Oceanic Day of the Indian Ocean, characteristic form of relief are distinguished: basins, individual ridges, plateau, mountains, gutters, canyons, etc. in the Western sector - the largest basins: Somali (with depths 3000-5800 m), Mascarenskaya (4500 -5300 m), Mozambique (4000-6000 m), Madagascar Basil (4500-6400 m), Agullas (4000-5000 m); Underwater ridges: Mascarensky Ridge, Madagascar, Mozambique; Plateau: Agullas, Mozambique Plateau; Separate mountains: Equator, African, Vernadsky, Hall, Bardina, Kurchatov; Amyrantky golod, Mauritius's gulch; Canyons: Zambezi, Tanganyika and Taghela. The northeast sector has brands: Arabian (4000-5000 m), central (5000-6000 m), coconut (5000-6000 m), North-Australian (5000-5500 m), West Australian Basin (5000-6500 m), naturalist (5000-6000 m) and South Australian brand (5000-5500 m); Underwater ridges: Maldives Range, East Indian Range, West Australian; Mountain array of Kuvier; Plateau Exmouth; Mill hill; Separate mountains: MSU, Shcherbakov and Athanasius Nikitin; East Indian bile; Canyons: Ind, Gang Rivers, Sitown and Murray. In the Antarctic sector - the basins: Cryro (4500-5000 m), African Antarctic Basin (4000-5000 m) and Australia-Antarctic Basin (4000-5000 m); Plateau: Kergelen, Cryau and Amsterdam; Separate mountains: Lena and Ob. Forms and sizes Kotlovin are different: from rounded with a diameter of about 400 km (Comorial) to oblong giants of 5,500 km long (central), various degrees of their isolation and relief of the bottom: from smooth or high-voltage to hilly and even mountainous.
Geological structure. The feature of the Indian Ocean is that its formation occurred both as a result of the split and immersion of continental arrays and as a result of the bottom of the bottom and neoplasms of the oceanic bark within the mid-oceanic (spreading) ridges, the system of which was repeatedly rebuilt. The modern system of the mid-ocean ridges consists of three branches converging at the point of the triple articulation Rodriguez. In the northern branch, the Arabian-Indian ridge continues to the north-west of the Zone of Transformer Owen Rift Rift Systems of the Gulf and the Red Sea and is connected to the intracontinental systems of East Africa rhyps. In the southeastern branch, the Central Indian Ridge and the Australia-Antarctic Rise are separated by the fault area of \u200b\u200bAmsterdam, which connected the same plateau with Volcanic Islands Amsterdam and Saint-Paul. The Arabian-Indian and Central Indian ridges are slow-maintaining (lifting speed 2-2.5 cm / year), have a well-pronounced rift valley, crossed by numerous transformers. Wide Australo Antarctic raising has no pronounced rift valley; Spreading speed on it is higher than in other ridges (3.7-7.6 cm / year). South of Australia, the raising of the Australian Antarctic zone of disorders is broken down, where the number of transformers increases and the spreading axis shifts in the southern direction. The ridges of the southwestern branch are narrow, with a deep rift valley, densely crossed by transform faults oriented at an angle to the stretch of the ridge. It is characterized by a very low spread rate (about 1.5 cm / year). The West Indian Range is separated from the African Antarctic Range of Prince-Eduard, Du Toyt, Andrew Bain and Marion, who shift the ridge axis by almost 1000 km south. The age of the oceanic cortex within the spreading ridges is predominantly oligocene-quaternary. The West Indian Range, the narrow Wedge introduced into the structure of the Central Indian Range, is considered the youngest.
The spreading ridges divide the ocean bed for three sectors - African in the West, Asia-Australian in the North-East and Antarctic in the south. Within the sectors there are various nature of the intraoanic lifting, represented by the Asseymic Ranges, Plateau and Islands. Tectonic (chuck) raises have a block structure with different cortex power; Often include continental remains. Volcanic raises are mainly associated with fault zones. Raises are natural borders of deep-sea boiling. The African sector is distinguished by the predominance of fragments of continental structures (including microcontinents), within which the power of the earth's crust reaches 17-40 km (Plateau Agullas and Mozambique, Madagascar Range with the island of Madagascar, separate blocks of the Mascarensky Plateau with the Bank of Seychelles and Saya de - Malya). The volcanic raising and facilities include the Comorian submarine ridge, topped with coral and volcanic islands, Amyrantky Range, Reunion Islands, Mauritius, Tromon, Massifaire. In the western part of the African Sector of the Indian Ocean (Western Somali Basin, the Northern Piece of the Mozambique Basin), adjacent to the eastern underwater edge of Africa, the age of the earth's cortex is predominantly Lateurish-Ranners; In the central part of the sector (Maskarenskaya and Madagascar Bowls) - lateral; In the northeastern part of the sector (the eastern part of the Somali Basin) - Paleocene-Eocene. In Somali and Muskarenskaya, the ancient spreads of spreading and crossing their transform faults were revealed.
For the North-Western (Priayatskaya) part of the Asia-Australian sector, the ridges of the block structure with an increased power of the oceanic cortex are characteristic of the ridges of the block structure with an increased power of the oceanic cortex, the formation of an ancient transform faults. These include the Maldives Range, crowned with the archipelagoes of the Coral Islands - Lakkadivsky, Maldives and Chagos; The so-called 79 ° ridge, Lanka Ridge with Mount Afanasia Nikitin, East Indian (the so-called ridge 90 °), Investigator, etc. Powerful (8-10 km) Indian indian rivers in the northern part of the Indian Ocean partially overlap extending In this direction, the ridges, as well as the structure of the transition zone, the Indian Ocean - Southeast Out of Asia. Marri Ridge in the northern part of the Arabian Basin, restricting from the south of the Oman Basin, is the continuation of the folded structures of sushi; Included in the Owen Fault Zone. South of the equator was revealed by a subskurotic zone of intraple deformations with a width of up to 1000 km, for which high seismicity is characteristic. She is drawn up in central and coconut basins from the Maldives Range to Zonda Globe. The Arabian Basin is littered with the bark of Paleocene-Eocene age, the central hollow - the crust of the Lately - Eocene age; The bark is the most young in the southern part of Kotlovin. In the coconut basin, the age of the bark varies from the late chalk in the south to Eocene in the north; In its northwestern part, the ancient axis of spreading, separated by the middle of Eocene Indian and Australian lithospheric plates. Coconut shaft is a latitudent lift with the numerous underwater mountains and islands (including coconut) - and the raising of the RU, adjacent to the sordian yellow, is separated by the South-Eastern (Privalist) part of the Asia-Australian sector. The West Australian Basil (Worton) in the central part of the Asia-Australian sector of the Indian Ocean is underwent in the northwest lateral bark, in the east - Lateura. Immersed continental blocks (edge \u200b\u200bplateaus Exmouth, Kuvier, Zenit, Naturalist) share the eastern part of the basin on separate depressions - Kuwier (north of the Cuvier Plateau), Perth (north of the Naturalist Plateau). The bark of the North Australian Basin (Argo) is the most ancient in the south (late Yura); It becomes younger in the northern direction (to early chalk). The Age of the South Australian Late Late - Eocene Bore. The Broken Plateau is an intrao-economic lift with an increased (from 12 to 20 km, according to various sources) the power of the bark.
In the Antarctic sector of the Indian Ocean, there are mainly volcanic intraoanic raising with an increased power of the earth's crust: Kergelen Plateau, Croza (Del Canyo) and Conrad. Within the largest plateau of Kergelen, presumably laid on an ancient transformer fault, the power of the earth's crust (according to some data, ranch age) reaches 23 km. Kergelen's island rising over the plateau are a multiphase volcanochoponic structure (composed of alkaline basalts and non -ogenic syenites). On the island of Herd - Neogen-Quaternary alkaline volcanics. In the western part of the sector there are Plateau Conrad with Volcanic Mountains Ob and Lena, as well as Plateau Croze with a group of Volcanic Islands Marion, Prince-Eduard, Cryau, folded with Quaternary basalts and intrusive arrays of Senitites and Montzonites. The age of the earth's crust within the African-Antarctic, Australian Antarctic Kotlovin and the Croza Locking Bowl - Eocene.
For the Indian Ocean, the predominance of passive outskins (mainland margin of Africa, Arabian and Industan Peninsulas, Australia, Antarctica) is characteristic. The active outskirt is observed in the northeastern part of the ocean (the Zonda Zone of Transition of the Indian Ocean - Southeast Asia), where there is a subduction (suspension) of the ocean lithosphere under the Zonda island arc. The subduction zone limited by the length is Macrana - revealed in the northwestern part of the Indian Ocean. Along Plateau Agullas, the Indian Ocean borders with the African continent on a transformer one.
The formation of the Indian Ocean began in the middle of the mesozoic in the process of spliting the Gondvanian part (see Gondwan) supercontinent of the contract, which was preceded by continental riftogenesis over the late Triassa - early chalk. The formation of the first sections of the oceanic cortex as a result of the lifting of continental plates began in late Yura in Somali (about 155 million years ago) and the North Australian (151 million years ago) of the Both. In Late Chalk, the bottom and neoplasm of the oceanic cortex experienced the northern part of the Mozambique Basin (140-127 million years ago). The Australian Department from Industan and Antarctica, accompanied by the disclosure of pools with the oceanic crust, began in early chalk (about 134 million years ago and about 125 million years ago, respectively). Thus, in early chalk (about 120 million years ago) there were narrow oceanic pools, cut into a supercontinent and separating it into separate blocks. In the middle of the chalk period (about 100 million years ago), the oceanic bottom began to grow intensively between the Industrial and Antarctic, which led to the Draif of the Industan in the northern direction. In the time interval of 120-85 million years ago, the axes of the spreading existing on the north and west of Australia, the coast of Antarctica and in the Mozambic Strait occurred. In Late Chalk (90-85 million years ago), the split between the Industan with the Maskarensky-Seychelles and Madagascar began, which was accompanied by a spreading of the bottom in the Mascaret, Madagascar and Creez, and the formation of the Australia-Antarctic raising. At the turn of Mela and Paleogen, Industan separated from the Maskarensky-Seychelles; An Arabian-Indian spreading ridge arose; There was a fracture of the axes of spreading in Maskarenskaya, Madagascar basins. In the middle of Eocene, the Indian lithospheric plate was united with Australian; A developing system of the mid-ocean ridges has been formed. Close to the modern appearance of the Indian Ocean acquired at the beginning - the middle of the Miocene. In the middle of Miocene (about 15 million years ago), when the Arabian and African slabs, the neoplasm of the oceanic cortex began in the Gulf of Aden and the Red Sea.
Modern tectonic movements in the Indian Ocean are marked in the mid-ocean ridges (associated with small-focus earthquakes), as well as in separate transformers. The region of intensive seismicity is the Zordsk island arc, where deep-focus earthquakes are due to the presence of a seismophocal zone immersed in the northeast direction. In case of earthquakes on the northeast outskirts of the Indian Ocean, the formation of tsunami.
Bottom precipitation. The rate of sedimentation in the Indian Ocean is generally lower than in the Atlantic and Pacific Oceans. The thickness of the modern bottom sediments varies from the intermittent distribution on the mid-ocean ridges to several hundred meters in deep-water basins and 5000-8000 m at the foot of the mainland slopes. Lime (mainly foraminifero-kokocolite) yers are most common, covering over 50% of the bottom of the bottom of the ocean (on the mainland slopes, ridges and the bottom of Kotlovin at depths to 4,700 m) in warm oceanic areas from 20 ° Northern latitude up to 40 ° Southern latitude with High biological productivity of water. Polygenic precipitations - red deep-water ocean clays - occupy 25% of the bottom area at depths of over 4700 m in the eastern and southeastern parts of the ocean from 10 ° Northern latitude of up to 40 ° of southern latitude and in areas of the bottom, removed from the islands and continents; In the area of \u200b\u200bthe tropics, red clays are interspersed with siliceous radiolerine, covering the bottom of the deep-water kotlovin of the equatorial belt. In deep-water sediments in the form of inclusions there are iron orders. Silicon, mainly diatoms, ibi occupy about 20% of the Indian Ocean DNA; Completed at large depths of south of 50 ° south latitude. The accumulation of terrigenous precipitation (pebbles, gravel, sands, aleurites, clay) occurs mainly along the coarse mainland and within their underwater, in the areas of river and iceberg, significant wind removal of the material. The precipitation covering the shelf of Africa is mainly of worship and coral origin, phosphorite specs are widely developed in the southern part. Along the north-western periphery of the Indian Ocean, as well as in the Andaman Basin and in Zonda, the bottom sediments are represented mainly by the deposits of torment (turbid) flows - turbidates with the participation of products of volcanic activities, underwater collaps, landslides, etc. Coral reefs are widespread in Western Parts of the Indian Ocean from 20 ° of southern latitude up to 15 ° Northern latitude, and in the Red Sea - up to 30 ° north latitude. In the rift valley of the Red Sea, outlets of metal tape brusons with a temperature of up to 70 ° C and salting to 300 were found. In metal precipitation, made of these brine, highly color and rare metals. On the mainland slopes, underwater mountains, the mid-oceanic ridges, indigenous yields (basalt, serpentinites, peridotite) are noted. The bottom sediments around Antarctica are allocated to a special type of iceberg sediment. They are characterized by a predominance of a variety of debris material, ranging from large boulders and ending with anemerics and thin yals.
Climate. Unlike the Atlantic and Pacific Oceans, having a meridional strike from the banks of Antarctica to the Northern Polar Circle and communicating with the Northern Arctic Ocean, the Indian Ocean in the northern tropical area is bounded by the sushi massif, which largely determines the characteristics of its climate. The uneven heating of the sushi and the ocean leads to a seasonal change of extensive minima and maxima of atmospheric pressure and to seasonal shifts of the tropical atmospheric front, which in the winter of the northern hemisphere recedes to the south to almost 10 ° of southern latitude, and in the summer it is located in the foothill areas of the South of Asia. As a result, the monsonic climate is dominated over the northern part of the Indian Ocean, for which the change in the direction of wind during the year is characteristic. Winter monsoon with relatively weak (3-4 m / s) and resistant northeastern winds is valid from November to March. During this period, north of 10 ° southern latitude was often stuffed. Summer monsoon with southwestern winds is observed from May to September. In the northern tropical region and in the Equatorial Ocean zone, the average wind speed reaches 8-9 m / s, often reaching the storm power. In April and October, it usually takes place the baric field, and during these months the wind outlook is unstable. Against the background of the prevailing monsoon atmospheric circulation over the northern part of the Indian Ocean, separate manifestations of cyclonic activity are possible. During the winter monsoon, there are cases of the development of cyclones over the Arabian Sea, during the summer monsoon - over the waters of the Arabian Sea and the Bengal Bay. Strong cyclones in these areas are sometimes formed and during the periods of changing monsoon.
Approximately 30 ° southern latitude in the central part of the Indian Ocean is a steady area of \u200b\u200bhigh pressure, the so-called South Indian maximum. This stationary anticyclone is an integral part of the southern subtropical high pressure region - it is saved all year round. Pressure in its center varies from 1024 GPa in July to 1020 GPa in January. Under the action of this anticyclone in the latitudinal band between 10 and 30 ° southern latitude, sustainable southeastern trade winds are blowing throughout the year.
South 40 ° Southern latitude The atmospheric pressure in all seasons is evenly reduced from 1018-1016 GPa on the southern periphery of the South Indian high to 988 GPa at 60 ° of southern latitude. Under the action of a meridional pressure gradient in the lower layer of the atmosphere, a steady Western air transfer is maintained. The greatest average wind speed (up to 15 m / s) is noted in the middle of the winter of the southern hemisphere. For higher southern latitudes of the Indian Ocean, the storm conditions are characterized during almost just a year, under which winds with more than 15 m / s, causing waves with a height of more than 5 m, have a repeatability of 30%. The south of 60 ° of South latitude along the coast of Antarctica is usually observed oriental winds and two or three cyclones per year, most often in July - August.
In July, the highest values \u200b\u200bof the air temperature in the drive layer of the atmosphere are noted at the top of the Persian Gulf (up to 34 ° C), the lowest on the coast of Antarctica (-20 ° C), over the Arabian Sea and the Bengal Bay on average 26-28 ° C. Above the water area of \u200b\u200bthe Indian Ocean, the air temperature varies almost everywhere in accordance with the geographical latitude.
In the southern part of the Indian Ocean, it smoothly drops from north to south by about 1 ° C every 150 km. In January, the highest values \u200b\u200bof air temperature (26-28 ° C) are marked in the equatorial belt, near the northern coasts of the Arabian Sea and the Bengal Bay - about 20 ° C. In the southern part of the ocean, the temperature is evenly reduced from 26 ° C on the southern tropic to 0 ° C and somewhat lower on the latitude of the southern polar circle. The amplitude of the annual fluctuations in the air temperature over most of the water area of \u200b\u200bthe Indian Ocean on average less than 10 ° C and only at the coast of Antarctica increases to 16 ° C.
The greatest amount of precipitation per year falls in the Bengal bay (over 5500 mm) and the eastern shores of Madagascar island (more than 3500 mm). In the northern coastal part of the Arabian Sea, the lowest amount of precipitation falls (100-200 mm per year).
The northeastern areas of the Indian Ocean are located in seismically active areas. The east coast of Africa and Madagascar Island, the shores of the Arabian Peninsula and the Industan Peninsula, almost all the island archipelagoes of volcanic origin, Western banks of Australia, especially the arc of the Sunda Islands, were repeatedly exposed to tsunami waves of different strength, right up to catastrophic. In 1883, after the explosion of Volcano Krakatau in the Jakarta area, tsunami with a wave height of over 30 m was registered, in 2004 the catastrophic consequences had a tsunami caused by an earthquake in the area of \u200b\u200bSumatra Island.
Hydrological mode. Seasonality in changes in hydrological characteristics (first of all temperature and flows) is most clearly manifested in the northern part of the ocean. The summer hydrological season here corresponds to the time of the southwestern monsoon (May - September), the winter - northeast monsoon (November - March). The peculiarity of the seasonal variability of the hydrological regime is that the restructuring of hydrological fields is somewhat discarded relative to meteorological fields.
Water temperature. In the winter of the northern hemisphere, the highest values \u200b\u200bof water temperature in the surface layer are observed in the equatorial belt - from 27 ° C off the coast of Africa to 29 ° C and more east of the Maldives. In the northern regions of the Arabian Sea and the Bengal Bay, the water temperature is about 25 ° C. In the southern part of the Indian Ocean, the zonal temperature distribution is characterized throughout, which smoothly decreases from 27-28 ° C at 20 ° of southern latitude to negative values \u200b\u200bat the edges of the drifting ice, located about 65-67 ° southern latitude. In the summer season, the highest values \u200b\u200bof water temperature in the surface layer are noted in the Persian bay (up to 34 ° C), in the north-west of the Arabian Sea (up to 30 ° C), in the eastern part of the equatorial zone (up to 29 ° C). In the coastal areas of the Somalia and Arabian peninsula at this time of the year, abnormally low values \u200b\u200bare observed (sometimes less than 20 ° C), which is the result of the lift to the surface of the cooled depth water in the Somali flow system. In the southern part of the Indian Ocean, the water temperature distribution throughout the year retains a zonal character with the difference that its negative values \u200b\u200bof the southern hemisphere are found much north, about 58-60 ° of southern latitude. The amplitude of the annual fluctuations in the water temperature in the surface layer is small and on average is 2-5 ° C, only in the area of \u200b\u200bthe Somali coast and in the Oman Gulf of the Arabian Sea exceeds 7 ° C. The water temperature quickly decreases vertically: at a depth of 250 m, it almost everywhere lowers below 15 ° C, deeper 1000 m - below 5 ° C. At a depth of 2000 m, the temperature of over 3 ° C is observed only in the northern part of the Arabian Sea, in the central regions - about 2.5 ° C, in the southern part there are from 2 ° C by 50 ° of southern latitude to 0 ° C off the coast of Antarctica. Temperatures in the deepest (over 5000 m) blades - from 1.25 ° C to 0 ° C.
The salinity of the surface waters of the Indian Ocean is determined by the balance between the magnitude of the evaporation and the total amount of precipitation and the river flow for each area. The absolute maximum of salting (over 40) is observed in the Red Sea and the Persian Gulf, in the Arabian Sea everywhere, with the exception of a small area in the southeastern part, salting above 35.5, in the 20-40 ° band of southern latitude - more than 35 ‰ . The area of \u200b\u200blow salting is located in the Bengal Bay and in the area adjacent to the Arc of the Sunda Islands, where the fresh river stock is large and falls out the greatest amount of precipitation. In the northern part of the Bangale Bay in February, the saline 30-31, in August - 20. The extensive tongue of water with salting to 34.5 ‰ 10 ° of southern latitude is pulled from the island of Java to 75 ° East longitude. In the pooltarctic waters, saline is everywhere below the average oceanic value: from 33.5 in February to 34.0 in August, its changes are determined by small coalion in the formation of sea ice and appropriate desalination during the melting period. Seasonal changes in saline are noticeable only in the upper, 250 meters, layer. With increasing depths, not only seasonal fluctuations are faded, but also the spatial variability of salting, deeper 1000 m it ranges from 35-34.5.
Density. The greatest water density in the Indian Ocean is noted in the Suez and Persian Gulf (up to 1030 kg / m 3) and in cold pointerctic waters (1027 kg / m 3), the average - in the most warm and salted waters in the North-West (1024-1024, 5 kg / m 3), the smallest - in the most collapsible waters in the northeastern part of the ocean and in the Bengal bay (1018-1022 kg / m 3). With depth, mainly due to lowering the water temperature, its density is growing, sharply increasing in the so-called leap of the jump, which is most noticeably expressed in the Equatorial Ocean zone.
Ice regime. The severity of the climate in the southern part of the Indian Ocean is such that the process of forming sea ice (at air temperature below -7 ° C) can occur almost all year round. The greatest development of ice cover reaches in September - October, when the width of the belt of drifting ice reaches 550 km, the smallest - in January-February. Ice cover is characterized by a large seasonal variability, its formation occurs very quickly. The ice edge moves to the north at a speed of 5-7 km / day, as quickly (up to 9 km / day) retreats south during the melting period. Speak is set annually, reaches width on average 25-40 km and almost completely melts by February. Drifting ice in coasts is moving under the action of the stock winds in the general direction to the West and the North-West. Near the northern edge of ice drift in the eastern direction. The characteristic feature of Antarctic Ice Cook is a large number of icebergs, laid out from Antarctica's output and shelf glaciers. Particular icebergs, which can reach a gigantic length of several tens of meters, is 40-50 m tested over water. Their amount is rapidly decreasing as it removes the mainland from the banks. The duration of the existence of large icebergs on average is 6 years old.
Flow. The circulation of surface waters in the northern part of the Indian Ocean is formed under the action of monsoon winds and therefore significantly change from the summer season to the winter. In February from 8 ° Northern latitude, the Nikobar Islands to 2 ° Northern latitude of the coast of Africa passes the surface winter monsoon flow with a speed of 50-80 cm / s; With a strain, passing about 18 ° south latitude, in the same direction the southern trade in the current, having an average speed on the surface of about 30 cm / s. Connecting from the coast of Africa, the water of these two streams give the beginning of the interpassive anti-crossing, carrying their waters east with speeds in the straighter about 25 cm / s. Along the North African coast with a common direction to the south, the water of the Somali flow, which is partially transmitting to the interpassatet counterchange, and the south of the Mozambique and the needle cape coming to the south with speeds of about 50 cm / s. Part of the southern trade in the eastern coast of the island of Madagascar turns along it to the south (Madagascar current). South 40 ° Southern latitude The entire water area of \u200b\u200bthe ocean crosses from the west to the east the stream of the longest and most powerful in the oceans of the Western winds of the flow (Antarctic circumpolar flow). Speeds in its strokes reach 50 cm / s, and consumption is about 150 million m 3 / s. At 100-110 ° Eastern longitude from it, a stream heading to the north and giving rise to West Australian flow is born. In August, the Somali course follows in the general direction to the northeast and at a speed of up to 150 cm / s Cognizes water to the northern part of the Arabian Sea, from where the monsoon flow, rich Western and South Coast of the Peninsula of the Industan and Sri Lanka Peninsula, carries water to the shores of the island Sumatra, turns out to the south and merges with the waters of the Southern Passat. Thus, in the northern part of the Indian Ocean, an extensive cycle, directed clockwise, consisting of monsoon, southern trade in and Somali flows, is created. In the southern part of the ocean from February to August, the picture of the flows changes little. The coast of Antarctica in a narrow coastal strip is observed all year round, the flow caused by the stock winds and directed from the east to the west.
Water masses. In the vertical structure of the aquatic masses of the Indian Ocean on hydrological characteristics and depth of the occurrence, surface, intermediate, deep and bottom waters differ. Surface waters are common in a relatively thin surface layer and on average, the upper 200-300 m. From north to south, water masses are distinguished: Persian and Arabian in the Arabial Sea, Bengal and South-Bengali in Bengal bay; Further, south of the equator, - Equatorial, tropical, subtropical, subnutrctic and Antarctic. As the depth increases, the differences between the adjacent water masses decrease and their number is reduced accordingly. Thus, in the intermediate waters, the lower boundary of which reaches 2000 m in moderate and low latitudes and up to 1000 m - in high, the Persian and Krasnoarskaya in the Arabian Sea, the Bengalskaya in the Bengal Gulf is allocated, and Antarctic intermediate aquatic mass. The deep waters are represented by the North Indian, the Atlantic (in the western part of the ocean), the Central Indian (in the eastern part) and the circumpolar antarctic water masses. Dindon waters everywhere, in addition to the Bengal Bay, are represented by one Antarctic bottom water mass that fills all the deep-water brands. The upper boundary of the bottom water is located on average on the horizon of 2500 m off the coast of Antarctica, where it is formed, up to 4000 m in the central areas of the ocean and rises almost up to 3000 m north of the equator.
Tides and excitement. The greatest spread on the shores of the Indian Ocean has half and incorrect semi-sufficient tides. Semi-diverse tides are observed on the African coast south of the equator, in the Red Sea, from the North-Western shores of the Persian Gulf, in the Bengal Gulf, from the northwestern coast of Australia. Incorrect traphers - at the Somalia Peninsula, in the Gulf of Aden, off the coast of the Arabian Sea, in the Persian Gulf, in the southwestern shores of the Zonda Island Arc. Daily and irregular daily tides are celebrated from the Western and South Baths of Australia. The highest tides are in the northwestern banks of Australia (up to 11.4 m), in the mouth of Indea (8.4 m), in the mouth of the Ganges (5.9 m), off the coast of the Mozambique Strait (5.2 m) ; In the open ocean, the magnitude of the tides varies from 0.4 m in the Maldives to 2.0 m in the southeastern part of the Indian Ocean. The excitement reaches the greatest force in moderate latitudes in the zone of the Western winds, where the repeatability of waves with a height of more than 6 m is 17% per year. Near the island of Kergelen registered waves with a height of 15 m and a length of 250 m, off the coast of Australia, respectively, 11 m and 400 m.
Flora and fauna. The main part of the Indian Ocean water area is located within the tropical and southern moderate belts. The absence in the Indian Ocean of the Northern High-Template and the action of monsoons leads to two multidirectional processes that determine the features of local flora and fauna. The first factor makes a deep-water convection that adversely affects the renewal of the deep water of the northern part of the ocean and the increase in the oxygen deficiency in them, which is particularly strongly expressed in the Krasnoral intermediate water mass, which leads to the dining of the species composition and reduces the total biomass of zooplankton in the intermediate layers. Upon exiting the poor oxygen waters in the Arabian Sea, local messengers occur on the shelf (the death of hundreds of thousands of tons of fish). At the same time, the second factor (monso) forms favorable conditions for high biological productivity in coastal areas. Under the action of the summer monsoon there is a saft of water along the Somali and Arabian coasts, which causes a powerful appendication that endowed on the surface of water rich in nutritional salts. Winter monsoon, although to a lesser extent, leads to a seasonal appearance with similar consequences from the west coast of the Industan Peninsula.
The coastal zone of the ocean is characterized by the greatest species diversity. For shallow tropical belts, numerous 6- and 8-ray maladporovy corals are characterized, hydrocalolls capable of creating underwater reefs and atolls together with red algae. Among the powerful coral buildings dwells the richest fauna of various invertebrates (sponges, worms, crabs, mollusks, marine hedgehogs, masters and starfish), small, but brightly painted fish coral reefs. Most of the coasts are engaged in mangrove thickets. At the same time, the fauna and flora of the beaches of the beaches and rocks are quantitatively depleted due to the depressing effect of sunlight. In a moderate belt, life in such sections of coasts is presented much richer; It develops thick thickets of red and brown algae (laminaries, fucses, macrocysts), are abundant diverse invertebrates. According to L. A. Zenkevich (1965), over 99% of all species living in the ocean of the bottom and bottom animals live on the littorals and subnamers.
For open spaces of the Indian Ocean, especially for the surface layer, the rich flora is also characteristic. The food chain in the ocean begins with microscopic single-cell vegetable organisms - phytoplankton, which inhabits mainly the uppermost (approximately 100-meter) layer of oceanic water. Among them are several types of periodinium and diatoms, and in the Arabian Sea - cyanobacteria (blue-green algae), often causing so-called water flowering during mass development. In the northern part of the Indian Ocean there are three areas of the highest phytoplankton products: the Arabian Sea, the Bengal Bay and the Andaman Sea. The largest products are observed off the coast of the Arabian Peninsula, where the number of phytoplankton sometimes exceeds 1 million CL / l (cells per liter). Its high concentrations are also observed in the subnutrctic and antarctic zones, where in the period of spring flowering there are up to 300,000 cl / l. The smallest phytoplankton (less than 100 cells) is noted in the central part of the ocean between the 18 and 38 ° parallels of the south latitude.
Zooplankton inhabits almost the whole crowd of oceanic waters, but its amount quickly decreases with increasing depth and to the bottom layers decreases by 2-3 orders. The phytoplankton is used for most of the zooplankton, especially inhabiting in the upper layers, therefore the paintings of the spatial distribution of phyto and zooplankton are largely similar. The greatest indicators of the biomass of zooplankton (from 100 to 200 mg / m3) - noted in the Arabian and Andaman seas, Bengal, Adensky and Persian Gulf. The main biomass of the ocean animals make up the contouring races (more than 100 species), slightly less glooping mollusks, jellyfish, siphofofor and other invertebrate animals. From unicellular typical radiolearians. In the Antarctic region of the Indian Ocean, a huge number of euffuzium rates of several species united under the name "Krill" are characterized. Euffaucidis creates the main fodder base for the largest animals on Earth - Music Whales. In addition, fish, seals, cephalopods, penguins and other species of birds eat the krelege.
Organisms that are freely moving in the marine environment (necton) are represented in the Indian Ocean in the main fish, cipal mollusks, cetaceans. Cattails, numerous squids and octopuses are common from charts in the Indian Ocean. Several species of volatile fish are most abundantly abundant from fish, glowing anchovies (corneters), Sardinell, Sardin, Macrolesechuk, Not Those, Sea Perch, several types of tunitsa, blue marlin, macrolarus, sharks, skates. Sea turtles and poisonous sea snakes live in warm waters. The fauna of aqueous mammals is represented by various cetaceans. From the preyed whales are common: blue, sowing, Finval, Gorbach, Australian (Kapsky) Chinese. Town whales are represented by coushlots, several types of dolphin (including kids). In the coastal waters of the southern part of the ocean, Lastonodi: Weddell Tylene, sealer-crabbed, cats - Australian, Tasmanian, Kergelen and South African, Australian Sea Lion, Sea Leopard, and others. Among the birds are most characteristic - wandering Albatross, Petrels, Big Fregat , Cormorants, Olushi, Pesorborn, Colt, Seagulls. South 35 ° South latitude, on the coasts of South Africa, Antarctica and Islands, are numerous colonies of several types of penguins.
In 1938, a unique biological phenomenon was discovered in the Indian Ocean - Latimeria Chalumnae live creeper fish, which was considered to be extinct tens of millions of years ago. "Fossil" Lathemeria lives at a depth of over 200 m in two places - near the Comoros and in the waters of the Indonesian archipelago.
Story study
Northern coastal areas, especially the Red Sea and deeply embedded bays, began to be used by a person for navigation and fisheries already in the era of ancient civilizations, a few thousand years before our era. For 600 years BC, Phoenician navigators who held in the service of the Egyptian Pharaoh Nehho II were reinforced by the Sea Africa. In 325-324, BC, the associate of Alexander Macedonian Narh, commanding the fleet, made swimming from India to Mesopotamia and made up the first descriptions of the shores from the mouth of the Indian River to the top of the Persian Gulf. In the 8-9th centuries, the Arabian Sea was intensively mastered the Arab Maritimeers who created the first locations and navigation guides on this area. In the 1st half of the 15th century, Chinese navigators under the leadership of Admiral Zhenge Hhe have made a range of swimming pools along the Asian coast to the west, reaching the banks of Africa. In 1497-99, the Portuguese Gama (Vasco da Gama) laid the sea route for Europeans to India and to the countries of Southeast Asia. A few years later, the Portuguese opened the island of Madagascar, Amilant, Comoros, Mascaren and Seychelles. Following the Portuguese in the Indian Ocean, the Dutch, the French, Spaniards and the British penetrated. The name "Indian Ocean" first appeared on European maps in 1555. In 1772-75 J. Cook penetrated the Indian Ocean to 71 ° of southern latitude and conducted the first deep-sea measurements. The beginning of the oceanographic studies of the Indian Ocean is based on systematic measurements of water temperature during the circulation of Russian ships "Rurik" (1815-18) and "Enterprise" (1823-26). In 1831-36, an English expedition on the Beagle ship was held, on which Ch. Darwin conducted geological and biological work. Complex oceanographic measurements in the Indian Ocean were carried out during the British expedition on the Chellenger ship in 1873-74. Oceanographic works in the northern part of the Indian Ocean performed in 1886 S. O. Makarov on Vityaz vessel. In the 1st half of the 20th century, oceanographic observations began to be carried out regularly, and by the 1950s they were conducted at almost 1,500 deep-water oceanographic stations. In 1935, the monograph of P. G. Schotta "Geography of the Indian and Pacific Oceans" was published - the first major publication that summarized the results of all previous studies in this region. In 1959, the Russian oceanographer A. M. Muroms residents published fundamental work - "The main features of the hydrogenology of the Indian Ocean". In 1960-65, the Scientific Committee on Oceanography UNESCO held an international Indookean expedition (Mioe), the largest of those who previously worked in the Indian Ocean. Scientists of more than 20 countries of the world (USSR, Australia, Great Britain, India, Indonesia, Pakistan, Portugal, USA, France, Germany, Japan, and others participated in the MioE program. In the course of MIO, large geographical discoveries are made: underwater West Indian and East Indian ridges, tectonic fault zones - Owen, Mozambique, Tasmanskaya, Diamantin, etc., Underwater mountains - Ob, Lena, Athanasia Nikitina, Bardina, Zenit, Equator and Dr., deep-water gutter - Ob, Chagos, Wim, Vityaz, etc. In the history of the study of the Indian Ocean, the results of studies performed in 1959-77 Research Ship "Vityaz" (10 flights) and dozens of other Soviet expeditions on ships of the Hydrometeorological Service and government community. Since the early 1980s, the study of oceans was carried out within 20 international projects. The studies of the Indian Ocean in the period of the International Experiment on the Circulation of the World Ocean (WOCE) were especially intensified. After its successful completion in the late 1990s, the volume of modern oceanographic information on the Indian Ocean increased twice.
Economic use
The coastal zone of the Indian Ocean is characterized by an extremely high population density. On the coasts and islands of the ocean, there are over 35 states in which about 2.5 billion people live (over 30% of the population of the Earth). The bulk of the coastal population is concentrated in South Asia (more than 10 cities with a population of over 1 million). In most countries in the region, the problems of acquiring living space, job creation, food, clothing and housing, medical care are acute.
The use of the Indian Ocean, like the other seas and oceans, is carried out in several main areas: transport, fishing, mineral resource mining, recreation.
Transport. The role of the Indian Ocean in maritime transportation has increased significantly with the creation of a Suez (1869) channel, which opened the short sea path of communication with the states of the waters of the Atlantic Ocean. The Indian Ocean is the area of \u200b\u200btransit and export of all sorts of raw materials, in which almost all large seaports have international significance. In the northeastern part of the ocean (in Malakki and Zonda Strait), the routes of the courts follow in the Pacific Ocean and back. The main article of exports to the United States, Japan and Western European countries are crude oil from the Persian Gulf District. In addition, agricultural products are exported - natural rubber, cotton, coffee, tea, tobacco, fruit, nuts, rice, wool; wood; Mineral raw materials - coal, iron ore, nickel, manganese, antimony, bauxite, etc.; Machines, equipment, tools and metal products, chemical and pharmaceutical products, textiles, processed precious stones and jewelry. The share of the Indian Ocean accounts for about 10% of the consignment of world shipping, at the end of the 20th century about 0.5 billion tons of cargo per year (according to IOC) was transported at its water area. In these indicators, it occupies 3rd place after the Atlantic and Pacific Oceans, inferior to them in the intensity of shipping and the total volume of freight, but surpassing all other maritime transport communications in terms of oil transportation. The main transport routes passing through the Indian Ocean are directed towards the Suez Channel, Malacca Strait, South Extras of Africa and Australia and along the northern coast. The most intense shipping in the northern regions, although it is limited to storm conditions during the summer monsoon, less intensively in the central and southern regions. Rising oil production in the countries of the Persian Gulf, in Australia, Indonesia and other places contributed to the construction and modernization of oil ports and the appearance of giants tankers in the water area of \u200b\u200bthe Indian Ocean.
The most developed transport highways for transportation of oil, gas and petroleum products: Persian Bay - Red Sea - Suez Canal - Atlantic Ocean; Persian Bay - Malack Strait - Pacific Ocean; The Persian Bay is the southern tip of Africa - the Atlantic Ocean (especially before the reconstruction of the Suez Canal, 1981); The Persian Bay is the coast of Australia (Port Fremanth). Mineral and agricultural raw materials are transported, textiles, precious stones, jewelry, equipment, computer equipment from India, Indonesia, Thailand. From Australia, carbon, gold, aluminum, aluminum, iron ore, diamonds, uranium ores and concentrates, manganese, lead, zinc; Wool, wheat, meat products, as well as internal combustion engines, passenger cars, electrical products, river vessels, glass products, steel rolled products, etc. In the oncoming streams, industrial goods, cars, electronic equipment, etc. are dominated. Important place in the transportation of Indian The ocean takes the transportation of passengers.
Fisheries. Compared to other oceans, the Indian Ocean has relatively low biological productivity, mining fish and other seafood is 5-7% of the total world catch. Fishing and non-breaking objects focuses mainly in the northern part of the ocean, and in the west twice the prey in the eastern part. The greatest volumes of bioproduct production are celebrated in the Arabian Sea at the West Coast of India and the coast of Pakistan. The Persian and Bengal bays are produced by shrimp, the eastern coast of Africa and the tropical islands - Langustov. In the open areas of the ocean in the tropical belt, the tuna is widely developed, which leads countries with a well-developed fishing fleet. In the Natrotarctic area produce not-studies, fish ice and curl.
Mineral resources. Almost on the entire shelf area of \u200b\u200bthe Indian Ocean, deposits of oil and natural fuel or oil and gas reference are revealed. The most industrial importance are actively developed by oil and gas fields in the bays: Persian (Persian Gulf Oil and Gas Pool), Suezkom (Oil and Gas Pool of the Suez Gulf), Cambaisky (Cambai Oil and Gas Pool), Bengali (Bengal Oil and Gas Pool); The northern coast of the island of Sumatra (North-Sumysnnaya Oil and Gas Pool), in the Timor Sea, from the North-West Coast of Australia (Oil and gas pool Carnarvon), in the Bass Strait (oil and gas plaster pool). Gas deposits are divided into the Andaman Sea, oil and gas areas - in the Red Sea, the Aden Gulf, along the coast of Africa. The coastal marine plaques of heavy sands are developed off the coast of the Island of Mozambique, along the south-western and northeast coasts of India, from the northeastern coast of Sri Lanka Island, along the south-west coast of Australia (Ilmenite, Rutile, Monazita and Zircon); In the coastal areas of Indonesia, Malaysia, Thailand (cassiterite mining). Industrial clusters of phosphorites were found on the shelves of the Indian Ocean. On the ocean's bed, large fields of iron orders are installed - a perspective source Mn, Ni, Cu, CO. In the Red Sea, the discovered metal tolls and precipitates are potential sources of iron, manganese, copper, zinc, nickel, etc.; There are deposits of rock salt. In the coastal zone of the Indian Ocean, sand for the construction and production of glass, gravel, limestone is mined.
Recreational resources. From the 2nd half of the 20th century, the use of recreational resources of the ocean is of great importance for the economy of coastal countries. Old and new resorts on the coast of the mainland and the numerous tropical islands in the ocean are developing. The most visited resorts are located in Thailand (Phuket Island, etc.) - over 13 million people per year (together with the coast and the islands of the Siamese Gulf of the Pacific Ocean), in Egypt [Hurghada, Sharm-Eshech (Sharm elms), etc. ] - Over 7 million people, in Indonesia (Bali Islands, Bintan, Kalimantan, Sumatra, Java, etc.) - over 5 million people, in India (Goa, etc.), in Jordan (Aqaba), in Israel (Eilat) , in the Maldives, in Sri Lanka, in the Seychelles, on Islands, Mauritius, Madagascar, South Africa, etc.
Sharm-Ash Sheikh. Hotel "Concord".
Portalities. On the banks of the Indian Ocean are oil-oil specialized ports: Ras Tanzanur (Saudi Arabia), Hark (Iran), Ash Shuyba (Kuwait). The largest ports of the Indian Ocean: Port Elizabeth, Durban (South Africa), Mombasa (Kenya), Dar-Es Salam (Tanzania), Mogadishu (Somalia), Aden (Yemen), El Kuwait (Kuwait), Karachi (Pakistan), Mumbai, Chennai, Calcutta, Candle (India), Chittagong (Bangladesh), Colombo (Sri Lanka), Yangon (Myanmar), Freemanntl, Adelaide and Melbourne (Australia).
Lit.: Geological and Geophysical Atlas of the Indian Ocean. M., 1975; Kanayev V. F. Relief of the Indian Ocean. M., 1979; Indian Ocean. L., 1982; Urintsev G. B. Regional geomorphology of the bottom of the oceans. Indian Ocean. M., 1989; Lithosphere of the Indian Ocean: according to geophysical data / Ed. A. V. Chekun, Yu. P. Nonfolnov. K., 1990; Naman V. G., Burkov V. A., Shcherbinin A.D. Dynamics of the Indian Ocean Water. M., 1997; Pushchashovsky Yu. M. Tectonics of the Earth. Election Works. M., 2005. T. 2: Tectonics of the oceans.
M. G. Deev; N. N. Turco (geological structure).
The Indian Ocean has the smallest number of seas compared to other oceans. In the northern part there are the largest seas: Mediterranean - the Red Sea and the Persian Bay, half-plated the Andaman Sea and the outskirts of the Arabian Sea; In the eastern part - Arafur and Timor Sea.
Islands relatively little. The largest of them are mainland and are located near the coast: Madagascar, Sri Lanka, Socotra. In the open part of the ocean there are volcanic islands - Mascarenskie, Cryau, Prince Eduard, and others. In tropical latitudes on volcanic cones, coral islands are towering - Maldives, Lakkadiv, Chagos, Coconut, Most Andaman et al.
Shores on S.-Z. and East are indigenous, on S.-V. And the West predominate apparent. The coastline is risen weakly, with the exception of the northern part of the Indian Ocean, almost all seas and large bays are located here (Adensky, Omansky, Bengali). In the southern part there are Karpenaria Bay, the Big Australian Bay and Spencer Bay, Saint Vincent, etc.
A narrow (up to 100 km) is stretched along the shores (shelf), the external edge of which has a depth of 50-200 m (only Antarctica and North-West Australia to 300-500 m). The mainland slope is a steep (up to 10-30 °) ledge, places dismembered by the submarine valleys of the Rivers of Ind, Gang, et al. In the northeastern part of the ocean, the Zonda island arc and a conjugate zonda flavor, to which the maximum depths are confined (up to 7130 m). The ridges, mountains and shafts of the Indian Ocean bed are divided into a row of Kotlovin, the most significant of which Arabian brand, West-Australian brand, the African Antarctic Basin. The bottom of these kitelins form accumulative and hilly plains; The first are located near the mainland in areas with a plenty of sedimentary material, the second - in the central part of the ocean. Among the numerous ridges of the bed with directness and length (about 5000 km), the Meridional East Indian Range, connecting to Yu, is allocated with the latitudinal West Australian ridge; Large meridional ridges are stretched to Yu. From the Industan Peninsula and about. Madagascar. Widely represented on the bed of the Ocean Volcanoes (Bardina, Shcherbakov, G. Lena, etc.), which in some places form large arrays (to C. from Madagascar) and chains (to B. from Coconut Islands). The average and ocean ridges are a mining system consisting of three branches, divergent from the central part of the ocean at S. (Arabian-Indian Ridge), Yu.-Z. (West Indian and African Antarctic Range) and Yu.-V. (Centralindian ridge and Australia-Antarctic raising). This system has a width of 400-800 km, a height of 2-3 km and the most dismembered by the axial (rift) zone with deep valleys and the boundary rift mountains; The transverse faults are characterized, along which horizontal bottom offsets are noted up to 400 km. The Australia-Antarctic raising, unlike the median ridges, is a more severe shaft with a height of 1 km and a width of up to 1500 km.
The bottom sediments of the Indian Ocean have the highest power (up to 3-4 km) at the foot of the mainland slopes; In the middle of the ocean - a small (about 100 m) power and in places of distribution of the dissected relief - intermittent distribution. The most widely represented foraminiferous (on the mainland slopes, ridges and at the bottom of the majority of Kotlovin at a depth of up to 4,700 m), diatoms (south of 50 ° J. sh.), Radiolari (near the equator) and coral precipitation. Polygenic precipitation - red deep-sea clays - spread south of the equator at a depth of 4.5-6 km and more. Territory precipitation - off the coast of the mainland. Chemogenic precipitates are represented mainly by iron-manganese concretions, and rifogenic - products of destruction of deep breeds. The exits of indigenous rocks are most common on the mainland slopes (sedimentary and metamorphic rocks), mountains (basalts) and mid-ocean ridges, where, in addition to basalts, serpentines, peridotites representing a low-changed substance of the upper mantle of the Earth are found.
For the Indian Ocean, the predominance of stable tectonic structures is characterized both on the bed (Thalassokraton) and in the periphery (mainland platforms); Active developing structures - modern geosyncline (Zonda arc) and georifogenali (mid-oceanic ridge) - occupy smaller areas and are continued in the respective structures of Indochina and rifts of East Africa. These main macrostructures, differ in morphology, the structure of the earth's crust, seismic activity, vulcanism, are divided into smaller structures: plates, usually corresponding to the bottom of oceanic kitelin, block ridges, volcanic ridges, places crowned with coral islands and banks (Chagos, Maldives and others .), Gutter-faults (Chagos, Obi, etc.), often dedicated to the foot of the chill ridges (East-Indian, West-Australian, Maldives, etc.), fault zones, tectonic ledges. Among the structures of the Indian Ocean layer, the northern part of the Muskarensky Range is a special place (according to the presence of continigric rocks - the granites of the Seychelles and the mainland type - the structure, which is apparently part of the ancient mainland Gondwana.
Minerals: On shelves - oil and gas (especially the Persian Bay), monazitic sands (coastal area of \u200b\u200bSouth-Western India), etc.; in rhythic zones - chromium, iron, manganese, copper, and dr.; On the bed - huge accumulations of iron-manganese nodules.
Northern Indian Ocean Musson Climate; In the summer, when the area of \u200b\u200blow pressure develops above Asia, the south-western flow of equatorial air, in winter - the northeastern flow of tropical air are dominated here. South 8-10 ° sh. Atmospheric circulation is much more consistent; Here in tropical (in summer and in subtropical) latitudes, sustainable southeastern trade winds are dominated, and in moderate latitudes - endopic cyclones in the east. In the tropical latitudes in the western part in the summer and autumn there are hurricanes. The average temperature of the air in the northern part of the ocean in the summer is 25-27 ° C, off the coast of Africa to 23 ° C. In the southern part, it decreases in summer to 20-25 ° C at 30 ° YU. sh., up to 5-6 ° C 50 ° sh. and below 0 ° C south of 60 ° sh. In winter, the air temperature varies from 27.5 ° C at the equator to 20 ° C in the northern part, up to 15 ° C to 30 ° YU. sh., up to 0-5 ° С 50 ° sh. and below 0 ° C south of 55-60 ° sh. At the same time, in the southern subtropical latitudes, the temperature in the West under the influence of a warm Madagascar flow by 3-6 ° C is higher than in the east, where there is a cold West Australian current. Cloudy in the monsoon northern part of the Indian Ocean in winter is 10-30%, in summer to 60-70%. In the summer there is also the greatest amount of precipitation. The average annual precipitation on V. Arabian Sea and the Bengal bay of more than 3000 mm, from the equator 2000-3000 mm, in the west of the Arabian Sea to 100 mm. In the southern part of the ocean, the average annual cloudiness is 40-50%, south of 40 ° sh. - up to 80%. The average annual precipitation in subtropics is 500 mm on V., 1000 mm on Z., in moderate latitudes of more than 1000 mm, Antarctica decreases to 250 mm.
The circulation of surface waters in the northern part of the Indian Ocean has a monsime character: in summer - Northeast and Eastern flow, in winter - south-west and west. In the winter months between 3 ° and 8 ° sh. The interpassate (equatorial) countercase develops. In the southern part of the Indian Ocean, the circulation of waters forms an anticyclonal cycle, which is formed from warm currents - southern trade in S., Madagascar and needle in the west and cold - the flow of Western winds in the south and West Australian in the east south of 55 ° YU. sh. Several weak cyclone cycles of water develop, off the coast of Antarctica with the eastern flow.
The thermal balance prevails the positive component: between 10 ° and 20 ° C. sh. 3.7-6.5 GJ / (m2 × year); between 0 ° and 10 ° sh. 1.0-1.8 gd / (m2 × year); between 30 ° and 40 ° sh. - 0.67-0.38 GJ / (m2 × year) [from - 16 to 9 kcal / (cm2 × year)]; between 40 ° and 50 ° sh. 2.34-3.3 gd / (m2 × year); South 50 ° sh. from -1.0 to -3.6 gd / (m2 × year) [from -24 to -86 kcal / (cm2 × year)]. In the consuming part of the thermal balance north of 50 ° sh. The main role belongs to the cost of heat to evaporation, and south of 50 ° sh. - Ocean heat exchange with an atmosphere.
The water temperature on the surface reaches a maximum (more than 29 ° C) in May in the northern part of the ocean. In the summer of the northern hemisphere, it makes it here 27-28 ° C and only at the coast of Africa decreases to 22-23 ° C under the influence of the exit to the surface of cold waters with depths. The equator is equal to 26-28 ° C and decreases to 16-20 ° C to 30 ° YU. sh., up to 3-5 ° С 50 ° sh. and below -1 ° C south of 55 ° sh. In the winter of the northern hemisphere, the temperature on C. is equal to 23-25 \u200b\u200b° C, at an equator 28 ° C, 30 ° YU. sh. 21-25 ° C, 50 ° sh. from 5 to 9 ° C, south of 60 ° sh. Temperatures are negative. In subtropical latitudes all year round in the West, the water temperature is 3-5 ° C higher than in the east.
The saltness of water depends on the water balance, which develops on average for the surface of the Indian Ocean from evaporation (-1380 mm / year), precipitation (1000 mm / year) and mainland (70 cm / year). The main stock of freshwater gives the River South Asia (Gang, Brahmaputra, etc.) and Africa (Zambezi, Limpopo). The greatest saline is celebrated in the Persian Gulf (37-39 ‰), in the Red Sea (41) and in the Arabian Sea (more than 36.5). In the Bengal Gulf and the Andaman Sea, it decreases to 32.0-33.0, in southern tropics - up to 34.0-34.5. In southern subtropical latitudes, saline exceeds 35.5 (maximum 36.5 in summer, 36.0 winter), and south of 40 ° YU. sh. Falls up to 33.0-34.3. The greatest water density (1027) is observed in Antarctic latitudes, the smallest (1018, 1022) is in the northeastern part of the ocean and in the Bengal Gulf. In the northwestern part of the Indian Ocean, the density of water is 1024-1024.5. The oxygen content in the surface layer of water increases from 4.5 ml / l in the northern part of the Indian Ocean to 7-8 ml / l south of 50 ° sh. At the depths of 200-400 m, the absolute size oxygen content is significantly less and varies from 0.21-0.76 on C. up to 2-4 ml / l in the south, at high depths, it is gradually gradually increased in the bottom layer 4.03 -4.68 ml / l. The color of water is predominantly blue, in the Antarctic latitudes of blue, places with greenish shades.
Evils in the Indian Ocean, as a rule, are small (off the shores of the open ocean and on the islands from 0.5 to 1.6 m), only in the vertices of some bays they reach 5-7 m; In Camboi Gulf 11.9 m. These are predominantly semi-sufficient character.
The ice are formed in high latitudes and are taken out by winds and trends together with icebergs in the northern direction (up to 55 ° sh. In August and up to 65-68 ° sh. In February).
The deep circulation and the vertical structure of the Indian Ocean are formed by water immersed in subtropical (subsurface water) and antarctic (intermediate water) of convergence zones and along the continental slope of Antarctica (bottom water), as well as incoming from the Red Sea and the Atlantic Ocean (deep water). The subsurface waters have at a depth of 100-150 m to 400-500 m. The temperature of 10-18 ° C, the saline 35.0-35.7 ‰, intermediate waters occupy a depth of 400-500 m to 1000-1500 m, have a temperature from 4 to 10 ° C, saline 34.2-34,6 ‰; The deep water at a depth of 1000-1500 m to 3500 m have a temperature of 1.6 to 2.8 ° C, saline 34.68-34.78 ‰; Dining water below 3500 m have in the south temperature from -0.07 to -0.24 ° C, saline 34.67-34.69 ‰, on C. - about 0.5 ° C and 34,69-34.77 ‰, respectively.
Flora and fauna
The entire water area of \u200b\u200bthe Indian Ocean lies within the tropical and southern moderate belts. For shallow tropical belts, numerous 6- and 8-beam corals are characterized, hydrocalolls capable of creating islands and atolls together with lime red algae. Among the powerful coral buildings, the richest fauna of various invertebrates (sponges, worms, crabs, mollusks, sea hedgehogs, masters and starfish), small, but brightly painted coral fish. Most of the coasts are occupied by mangrove thickets, which highlights or a fishing fish, a long time to exist in the air. The fauna and flora of the sewing into the tump of beaches and rocks is quantitatively depleted as a result of the depressing effect of sunlight. In a moderate belt, life in such sections of coasts is presented much richer; It develops thick thickets of red and brown algae (laminaries, fukusy, reaching huge sizes of macrocystis), are abundant diverse invertebrates. For open spaces of the Indian Ocean, especially for the surface layer of water thickness (up to 100m), a rich flora is also characteristic. From unicellular planktonal algae, several types of cordial and diatoms of algae predominate, and in the Arabian Sea - cinema algae, often causing so-called water flowering during mass development.
The bulk of the ocean animals make up the contouring rags (more than 100 species), then follow the mollusk, jellyfish, siphofofores, etc. invertebrates. From unicellites are characterized by radolaria; Numerous squid. Several species of volatile fish are most abundant from fish, glowing anchovies - microfids, corneters, large and small tuna, sailboat fish and a variety of sharks, poisonous sea snakes. Sea turtles and large marine mammals are common (dugoni, toothy and toothless whales, laston-either). Among the birds are most characteristic of albatrosis and frigates, as well as several types of penguins, inhabiting the coast of South Africa, Antarctica and Islands lying in a temperate ocean belt.
The Indian Ocean is the third in the size of the Ocean of the Earth, covering about 20% of its water surface. Its area is 76.17 million km², the volume is 282.65 million km³. The deepest point of the ocean is in the Zonda referee (7729 m).
- Area: 76 170 thousand km²
- Volume: 282 650 thousand km³
- The greatest depth: 7729 m
- Average depth: 3711 m
In the north, wash Asia, in the West - Africa, in the East - Australia; In the south borders with Antarctica. The border with the Atlantic Ocean passes at 20 ° Meridian of Eastern Longitude; With quiet - at 146 ° 55 'Meridian of Eastern Longitude. The northernmost point of the Indian Ocean is approximately 30 ° north latitude in the Persian Gulf. The width of the Indian Ocean is approximately 10,000 km between the southern dots of Australia and Africa.
Etymology
The ancient Greeks known to them by the western part of the ocean with the surrounding seas and the bays called the Eritrea Sea (Dr. Greek. Ἐρυθρά θάλασσα - red, and in the old Russian sources the Cherry Sea). Gradually, this name began to attribute only to the nearest sea, and the ocean is called in India, the most famous at that time by its riches of the country on the shores of the ocean. So Alexander Macedonian in the IV century BC. e. Calls his Indicon Pelagos (Dr.-Greek. ἰνδικόν πέλαγος) - "Indian Sea". Arabs are known as Bar El Hind (modern Arab. المحيط الهندي - Al-Mụhӣ̣t al-Hindiy) - "Indian Ocean". From the XVI century, the name of the Oceanus Indicus (lat. Oceanus Indicus) was approved from the XVI century. Oceanus Indicus - Indian Ocean.
Physico-geographical characteristics
General
The Indian Ocean is mainly located south of the tropic of cancer between Eurasia in the north, Africa in the West, Australia in the East and Antarctica in the south. The border with the Atlantic Ocean passes through the Meridian of the cape needle (20 ° V.D. To the coast of Antarctica (the land of the queen mod)). The border with the quiet ocean passes: south of Australia - on the eastern border of Bassova Strait to Tasmania Island, then on Meridian 146 ° 55 'V.D. to Antarctica; North of Australia - Between the Andaman Sea and Malakksky Strait, further along the southwestern shore of the island of Sumatra, the Zonda Strait, the southern coast of Java Island, the southern borders of the seas of Bali and Sava, the northern border of the Arafur Sea, the southwestern shore of New Guinea and the Western border of Torresov Strait . Sometimes the southern part of the ocean, with the northern border from 35 ° YU. sh. (on the basis of circulation of water and atmosphere) to 60 ° sh. (According to the nature of the Relief of the bottom), refer to the Southern Ocean, which is not officially allocated.
Sea, Bay, Islands
The area of \u200b\u200bthe seas, the bays and the straits of the Indian Ocean is 11.68 million km² (15% of the total area of \u200b\u200bthe ocean), the volume of 26.84 million km³ (9.5%). Seas and main bays located along the coast of the ocean (clockwise): Red Sea, Arabian Sea (Adenian Bay, Omansky Bay, Persian Bay), Lakkadiv Sea, Bengal Bay, Andaman Sea, Timor Sea, Arafur Sea (Carpenary Bay), Big Australian Bay, Musona Sea, Sea Davis, Sea Commonwealth, Cosmonauts Sea (the last four sometimes relate to the Southern Ocean). 
Some of the islands - for example, Madagascar, Socotra, Maldives - are fragments of ancient continents, the other - Andaman, Nicobar or Christmas Island are volcanic origin. The largest island of the Indian Ocean - Madagascar (590 thousand km²). The largest islands and archipelagoes: Tasmania, Sri Lanka, Archipelago Kergelen, Andaman Islands, Melville, Mascarenie Islands (Reunion, Mauritius), Kangaroo, Nias, Mentavai Islands (Siberut), Socotra, Soot-Island, Comoros, Tywi Islands (Batarst ), Zanzibar, Simlue, Fürno Islands (Flinders), Nicobar Islands, Keshm, King, Bahrain Islands, Seychelles, Maldives, Chagos Archipelago. 
The history of the formation of the Indian Ocean
In early Russian time, the ancient supercontinent of Gondwan began to split. As a result, Africa was formed with Arabia, Industan and Antarctica with Australia. The process ended at the turn of Jurassic and Cretaceous periods (140-130 million years ago), and a young Wpadin of the Contemporary Indian Ocean began to form. In the chalk period, the bottom of the ocean has grown due to the movement of Industan to the north and reduction of the Ocean Oceans and Tetis. In the lateral time began the split of a single Australo Antarctic mainland. At the same time, as a result of the formation of a new rift zone, the Arabian stove soldered from African, and the Red Sea and the Aden Bay were formed. At the beginning of the Cenozoic era, the exploitation of the Indian Ocean was stopped toward the quiet, but continued towards the Tethis sea. At the end of the Eocenta - the beginning of the oligocene, a clash of Industan with the Asian continent occurred. 
Today the movement of tectonic plates continues. The axes of this movement are the mid-oceanic rift zones of the African Antarctic Range, the Central Indian Range and the Australian Antarctic Raising. The Australian stove continues to move to the north at a speed of 5-7 cm per year. In the same direction at a speed of 3-6 cm per year, the Indian stove continues to move. The Arabian stove moves to the northeast at a speed of 1-3 cm per year. From the African Plate, the Somali stove in the East African rift zone, which moves with a speed of 1-2 cm per year in the northeast direction. On December 26, 2004, in the Indian Ocean, the island of Symalue, located near the North-West shore of Sumatra Islands (Indonesia), has happened the most largest observation of the earthquake of magnitude to 9.3. The reason was the shift of about 1200 km (according to some estimates - 1600 km) of the earth's crust at a distance of 15 m along the subduction zone, as a result of which the Industan cooker moved under the Burmese slab. The earthquake caused tsunamis, which brought enormous destruction and a huge number of dead (up to 300 thousand people). 
Geological structure and terrain of the Indian Ocean
Mid-oceanic ridges
The mid-oceanic ridges divide the bottom of the Indian Ocean for three sectors: African, Indo-Australian and Antarctic. Four mid-oceanic ridges are distinguished: West Indian, Arabian-Indian, Centraline Ridges and Australia-Antarctic Raising. The West Indian Range is located in the southwestern part of the ocean. It is characterized by underwater vulcanism, seismicity, rifogenic bark and the rift structure of the axial zone, its sect several oceanic faults of the submeridional strike. In the area of \u200b\u200bRodriguez Island (Mascarensky Archipelago), there is a so-called triple connection, where the ridge system is divided into north to the Arabian-Indian ridge and southwest to the Centraline Range. The Arabian-Indian ridge is composed of ultrabasic rocks, a number of sequeling faults of the submeridal strike were revealed, with which very deep depressions are connected (oceanic sterns) with depths of up to 6.4 km. The northern part of the ridge crosses the most powerful Owen Rift, along which the northern segment of the ridge experienced a shift of 250 km north. Next to the West, the rift zone continues in the Gulf of Aden and in the North-North-West in the Red Sea. Here, the rift zone is composed of carbonate sediments with volcanic ashes. In the rift zone of the Red Sea, the thickness of evaporites and metal alone were found, associated with powerful hot (up to 70 ° C) and very saline (up to 350) juvenile waters. 
In the south-west direction from the triple compound, the Centraline-sished ridge extends, which has a well-pronounced rift and flank zones, ending in the south of Volcanic Plateau Amsterdam with the Volcanic Islands of Saint-Paple and Amsterdam. From this plateau in the East-South-East, an Australo Antarctic raising extends, having a view of a wide, weakly developed arch. In the eastern part, the lift is disseminated by a series of meridional faults on a number of segments shifted relative to each other in the meridional direction.
African ocean segment
Submarine in the africa has a narrow shelf and a clearly pronounced mainstream slope with the stained plateau and the mainland fit. In the south, the African continent forms the protrusions nominated to the south: the bank of Agullas, Mozambique and Madagascar ridges, folded by the earth's crust of the mainland. The continental foot forms expanding to the south along the coast of Somalia and Kenya, the inclined plain, which continues in the Mozambician Strait and borders Madagascar from the east. East of the sector passes the Muskarent Range, in the northern part of which are the Seychelles.
The surface of the ocean bed in the sector, especially along the mid-oceanic ridges, is dissected by numerous ridges and hollows associated with the zones of submeridional direction faults. Many underwater volcanic mountains are found, most of which are sustained by coral superstructures in the form of atolls and underwater coral reefs. Between mountain raising are the basins of the Ocean Lodge with hilly and mountain relief: Agullas, Mozambique, Madagascar, Mascarenskaya and Somali. In the Somali and Muskarenskaya, the basins are formed extensive flat abissual plains, which comes by a significant amount of terrigenous and biogenic sedimentary material. In the Mozambique, the Underwater Valley of the Zambezi River is located with the removal cone system.
Indo-Australian Ocean Segment
The Indo-Australian segment occupies half the Indian Ocean Square. In the West in the meridional direction, the Maldives ridge passes, on the vertex surface of which is the islands of Lakkadiv, Maldives and Chagos. The ridge is complicated by the crust of the continental type. Along the coast of Arabia and Industan, a very narrow shelf, a narrow and steep mainstream and a very wide mainland fit, mainly formed by two giant cones of the removal of mudflows of the ind and gang rivers. These two rivers are in the ocean 400 million tons of debris material. The India Cone is far back to the Arabian Basin. And only the southern part of this basin is occupied by a flat asbissal plain with separate underwater mountains.
Almost exactly 90 ° c. By 4000 km from the north to the south, the bilying oceanic eastern Indian ridge is stretched. There is a central brand between the Maldives and East Indian ridges - the largest brand of the Indian Ocean. Its northern part occupies a Bengal cone (from the Gang River), to the southern border of which the abissual plain is adjacent. In the central part of the basin there is a small ridge of Lanka and Underwater mountain Athanasius Nikitina. To the east of the East-Indian ridge, coconut and West-Australian brands are located, separated by a chump sub-lifeline-oriented coconut raising with coconut and christmas islands. In the northern part of the coconut basin there is a flat abissal plain. From the south, it is limited to the West Australian raising, cool to the south and hollow under the bottom of the basins to the north. From the south, West-Australian raising is limited to a steep ledge associated with Diamantine faults zone. In the zone of the Ralles, deep and narrow rabes are combined (the most significant - Ob and Diamatian) and numerous narrow horns. 
The transition region of the Indian Ocean is represented by the Andamansky flavor and deep-water Zonda refuge, to which the maximum depth of the Indian Ocean is timed (7209 m). The external ridge of the Zonda Island Arc is the underwater mentai ridge and its continuation in the form of Andaman and Nicobar Islands.
Underwater Painting Australian Mainland
The northern part of the Australian continent is bored with a wide Sakhulian shelf with a multitude of coral buildings. By the south, this shelf narrows and re-expands off the coast of South Australia. The mainland slope is complicated by the edge plateau (the largest of them is the plateau of Exmouth and naturalists). In the western part of the West-Australian brand, raising Zenit, Kuvye and others, which are pieces of the continental structure are located. There is a small South Australian brand between the southern underwater outskirts of Australia and the Australia-Antarctic raising, which is a flat abissual plain.
Antarctic ocean segment
The Antarctic segment is limited by the West Indian and Central Indian ridges, and from the south - the banks of Antarctica. Under the influence of tectonic and glaciological factors, the shelf Antarctica is ovelable. A wide mainstream slope is cut through large and wide canyons, according to which the stock of overcooked water from the shelf in the abissual depressions is carried out. The continental foot of Antarctica is widely and significant (up to 1.5 km) with a capacity of loose deposits.
The largest protrusion of the Antarctic mainland is Kergelen Plateau, as well as the volcanic lift of the Islands of Prince Eduard and Cryau, which are divided by the Antarctic sector for three basins. In the West there is an African Antarctic brand, which is half located in the Atlantic Ocean. Most of its bottom is a flat abissal plain. Located norther, the Crooke is distinguished by a large-column dermal of the bottom. Australo Antarctic Basin, lying to the east of Kergelena, in the southern part is occupied by a flat plain, and in North - Assocomate hills.
Bottom sediments
In the Indian Ocean, lime foraminifera-kokocolite sediments prevail, occupying more than half of the bottom area. The widespread development of biogenic (including coral) lime deposits is due to the provision of a large part of the Indian Ocean within the tropical and equatorial belts, as well as a relatively small depth of oceanic kitelins. Numerous mountain lifts are also favorable for the formation of lime precipitation. In the deep-sea parts of some Kotlovin (for example, Central, West Australian), deep-sea red clays are locked. In the equatorial belt are characterized by radilation ils. In the southern cold part of the ocean, where conditions for the development of diatomic flora are particularly favorable, silly diatomic deposits are presented. The Antarctic Beach is deposited by iceberg sediments. At the bottom of the Indian Ocean, iron ordered concretions received significant distribution, dedicated mainly to the areas of deposits of red clays and radiolarium ils.
Climate
In this region, four climatic belts are distinguished, stretched along parallels. Under the influence of the Asian continent in the northern part of the Indian Ocean, a monsonic climate is established with frequent cyclones moving towards the coasts. High atmospheric pressure over Asia in winter causes the formation of northeast monsoon. In the summer, it is replaced by a wet south-western monsoon carrying air from the southern regions of the ocean. During the summer monsoon, the wind is often the power of more than 7 points (with a repeatability of 40%). In the summer, the temperature above the ocean is 28-32 ° C, in winter it drops to 18-22 ° C.
Southeast Passat dominates in the southern tropics, which in winter does not apply to the north of 10 ° C.Sh. The average annual temperature reaches 25 ° C. In zone 40-45 ° Yu.Sh. Throughout the year, the Western transfer of air masses is characterized, especially strong in moderate latitudes, where the repeatability of the storm weather is 30-40%. In the middle part of the ocean, storm weather is associated with tropical hurricanes. In winter, they can occur in the southern tropical zone. Most often, hurricanes arise in the western part of the ocean (up to 8 times a year), in the districts of Madagascar and the Muskarent Islands. In subtropical and moderate latitudes in the summer, the temperature reaches 10-22 ° C, and in winter - 6-17 ° C. From 45 degrees and south are characterized by strong winds. In winter, the temperature ranges here from -16 ° C to 6 ° C, and in summer - from -4 ° C to 10 ° C.
The maximum amount of precipitation (2.5 thousand mm) is timed to the eastern region of the equatorial zone. There is also an increased cloudiness (more than 5 points). The smallest precipitation is observed in the tropical areas of the southern hemisphere, especially in the eastern part. In the northern hemisphere most of the year, clear weather is characteristic of the Arabian Sea. Maximum clouds are observed in the Antarctic waters.
Indian Ocean Hydrological Mode
Circulation of surface water
In the northern part of the ocean, there is a seasonal change of flows caused by monsoon circulation. In winter, a south-west monsoon flow started in the Bengal Bay. South 10 ° C. sh. This course goes to the western flow crossing the ocean from the Nikobar Islands to the shores of East Africa. Next, it branches: one branch comes to the north into the Red Sea, the other - south to 10 °. sh. And, turning to the East, gives rise to equatorial anti-countercase. The latter crosses the ocean and at the coast of Sumatra is again divided into a part that goes into the Andaman Sea and the main branch, which between the small probe islands and Australia is sent to the Pacific Ocean. In the summer, the south-eastern monsoon provides the movement of the entire mass of surface waters to the East, and the equatorial counterfeit disappears. The summer monsoon flow begins off the coast of Africa with a powerful Somali course, to which the course of the Red Sea is joined in the area of \u200b\u200bthe Gulf. In the Bengal Gulf, the summer monsoon flow is divided into the North and South, which is poured into the southern trade house.
In the southern hemisphere of flows are constant, without seasonal oscillations. The South Passatom Cotton Increased Passyat crosses the ocean from the east to the west to Madagascar. It is enhanced in the winter (for the southern hemisphere) time, due to the additional nutrition of the waters of the Pacific Ocean, entering along the North Bank of Australia. Madagascar has a southern trade house for branches, giving the beginning of an equatorial anti-countercord, Mozambique and Madagascar currents. Merging the south-west of Madagascar, they form a warm course of Agullas. The southern part of this course goes to the Atlantic Ocean, and the part is poured during the Western winds. On the approach to Australia, from the latter, the cold Western Australian current is moving to the north. In the Arabian Sea, Bengal and Big Australian bays and in the Narterctic waters there are local cyphans.
For the northern part of the Indian Ocean, a predominance of a semi-sufficient tide is characterized. The amplitudes of the tide in the open ocean are small and on average are 1 m. In the Antarctic and subnatrotic zones of the amplitude of the tide, decreases from east to west from 1.6 m to 0.5 m, and near the shores are increased to 2-4 m. Maximum amplitudes are noted between Islands, in shallow bays. In the Bengal bay, the magnitude of the tide is 4.2-5.2 m, near Mumbai - 5.7 m, Yangon - 7 m, from the North-West Australia - 6 m, and in the port of Darwin - 8 m. In the rest of the amplitude of the tide about 1-3 m.
Temperature, water salinity
In the Equatorial Zone of the Indian Ocean, the temperature of the surface waters is about 28 ° C both in the western and eastern parts of the ocean. In the Red and Arabian seas, the winter temperature decreases to 20-25 ° C, but in the summer in the Red Sea, maximum temperatures are installed for the entire Indian Ocean - up to 30-31 ° C. High winter water temperatures (up to 29 ° C) are characteristic of the shores of North-West Australia. In the southern hemisphere in the same latitudes in the eastern part of the ocean, the water temperature in winter and in summer is 1-2 ° lower than in Western. The water temperature is below 0 ° C in the summer, south of 60 ° is noted. sh. Lyhodovka in these areas begins in April and the thickness falling to the end of winter reaches 1-1.5 m. Melting begins in December-January, and the waters of the waters come to March. In the southern part of the Indian Ocean, icebergs are common, sometimes north of 40 ° YU. sh.
The maximum saline of surface waters is observed in the Persian Gulf and the Red Sea, where it reaches 40-41. High salting (more than 36) is also observed in the southern tropical belt, especially in the eastern regions, and in the Northern Hemisphere also in the Arabian Sea. In the neighboring Bengal bay due to the desonant influence of the Ganges running with Brahmaputra and Iravadi, salting decreases to 30-34. Increased salinity correlates with the zones of maximum evaporation and the smallest amount of atmospheric precipitation. The reduced saline (less than 34) is characteristic of the priorctic water, where the strong ceiling effect of melting glacier waters is affected. The seasonal difference of saline is significantly only in the Antarctic and Equatorial zones. In winter, the desalinated waters from the northeastern part of the ocean are transferred to the monsoon flow, forming a lower salting language along 5 ° C. sh. In summer, this language disappears. In the Arctic waters, in the winter, the saline increases somewhat due to the coalion of water in the process of formation. From the surface to the bottom of the ocean, salting decreases. Dindon waters from the equator to arctic latitudes are salty 34.7-34.8.
Water masses
The water of the Indian Ocean is divided into several water masses. In part ocean north of 40 ° sh. Allocate central and equatorial surface and subsurface water masses and the underlying (deeper 1000 m) deep. North to 15-20 ° sh. The central water mass is distributed. The temperature varies with a depth of 20-25 ° C to 7-8 ° C, the saline is 34.6-35.5. Surface layers north of 10-15 ° YU. sh. Make up equatorial aqueous mass with a temperature of 4-18 ° C and salting 34.9-35.3. This aqueous mass is characterized by significant speeds of horizontal and vertical movement. In the southern part of the ocean, the subnutrctic (temperature 5-15 ° C, saline up to 34) and Antarctic (temperature from 0 to -1 ° C, saline due to melting ice drops to 32 ‰). The deep aqueous mass is divided into: very cold circulation, which are formed by the lowering of the Arctic aqueous masses and the inflow of circulation water from the Atlantic Ocean; South Indian, emerging as a result of lowering subarctic surface waters; North Indian, resulting dense waters arising from the Red Sea and the Oman Bay. Deeper than 3.5-4 thousand M bottom aqueous masses, forming from the Antarctic undercase and dense saline waters of the Red Sea and the Persian Gulf.
Flora and fauna
Flora and the fauna of the Indian Ocean are extremely diverse. The tropical area is allocated by the wealth of plankton. Single-cellular algae trikhodesimium (cyanobacteria) is especially abundant (cyanobacteria), due to which the surface layer of water is very turbulent and changes its painting. Plankton of the Indian Ocean is distinguished by a large number of glowing at night of organisms: periodines, some types of jellyfish, comb, shells. Promotional painted sifoforphors are abundantly found, including poisonous phzasals. In moderate and Arctic waters, the main representatives of the plankton are coppes, eufauguids and diatoms. The most numerous fishes of the Indian Ocean are Corimps, tuna, not denotine and a variety of sharks. Of the reptiles there are several types of giant sea turtles, marine snakes, mammals - cetacean (toothless and blue whales, coushlots, dolphins), seals, sea elephants. Most cetaceans live in moderate and indoor areas, where, due to the intensive mixing of the waters, favorable conditions arise for the development of planktonic organisms. Birds are represented by albatrosses and frigates, as well as several types of penguins inhabiting the coast of South Africa, Antarctica and Islands lying in a moderate belt of the ocean. 
The vegetation world of the Indian Ocean is represented by brown (sargassic, turbines) and green algae (cauleler). Lime algae and Khalimeda, which participate together with corals in the construction of reef buildings, are also magnificently developing. In the process of activity of rhyme-forming organisms, coral platforms are created, which sometimes reach the widths of several kilometers. Typical for the coastal zone of the Indian Ocean is phytocenosis formed by mangrove thickets. Especially such thickets are characteristic of the mouths of the rivers and occupy significant areas in Southeast Africa, in West Madagascar, in Southeast Asia and other districts. For moderate and pointerctic waters, red and brown algae are most characteristic, mainly of Fukusov and Laminarium groups, Porphira, Helidium. In the sugar areas of the southern hemisphere there are giant macrocysts. 
Zoobenthos is represented by a variety of mollusks, limestone and flint sponges, iglozzy (sea hedgehogs, starfish, officers, wilderness), numerous crustaceans, hydroedes, msanka. In the tropical zone, coral polyps are widespread.
Ecological problems
Human economic activity in the Indian Ocean led to pollution of its waters and to reduce biodiversity. At the beginning of the 20th century, some kinds of whales turned out to be almost completely exterminated, others - coushlots and savory - still preserved, but their quantity declined. Since the 1985-1986 season, the International Commission on Whales was introduced a complete moratorium on commercial whaling of any species. In June 2010, at the 62nd meeting of the International Whale Commission under pressure from Japan, Iceland and Denmark moratorium was suspended. The Mauritius DRONT, destroyed by 1651 on the island of Mauritius, became a symbol of extinction and disappearance of species. After he is extinct, people first have formed the view that they can cause extinction and other animals. 
A greater danger in the ocean is water pollution with oil and petroleum products (main pollutants), some heavy metals and the waste of the nuclear industry. Through the ocean, the routes of oil supplies transporting oil from the Persian Gulf countries are running. Any major accident can lead to an ecological catastrophe and death of a plurality of animals, birds and plants.
States of the Indian Ocean
States along the borders of the Indian Ocean (clockwise):
- South Africa Republic
- Mozambique,
- Tanzania,
- Kenya,
- Somalia,
- Djibouti
- Eritrea,
- Sudan,
- Egypt,
- Israel,
- Jordan,
- Saudi Arabia,
- Yemen,
- Oman,
- United Arab Emirates,
- Qatar,
- Kuwait,
- Iraq,
- Iran,
- Pakistan,
- India,
- Bangladesh
- Myanmar
- Thailand,
- Malaysia,
- Indonesia,
- East Timor,
- Australia.
In the Indian Ocean there are island states and ownership of non-regional states:
- Bahrain,
- British Territory in the Indian Ocean (United Kingdom),
- Comoros,
- Mauritius,
- Madagascar,
- Mayotte (France),
- Maldives,
- Reunion (France),
- Seychelles,
- French South and Antarctic Territories (France),
- Sri Lanka.
Story study
The shores of the Indian Ocean is one of the areas of the settlement of the most ancient peoples and the emergence of the first river civilizations. In the deep antiquity of the court type, Johnok and Katamarans were used by people for sailing, with passing monscons from India to East Africa and back. The Egyptians for 3500 years before our era were a lively maritime trade with the countries of the Arabian Peninsula, India and East Africa. Mesopotamia countries for 3000 years BC made marine hiking to Arabia and India. From the 6th century to our era, the Phoenicians, according to the testimony of Greek historian Herodotus, made marine campaigns from the Red Sea on the Indian Ocean to India and around Africa. In the VI-V centuries BC, Persian merchants led maritime trade from the mouth of the Indian River along the eastern coast of Africa. At the end of the Indian campaign of Alexander Macedonsky in 325 BC, the Greeks of the Greeks with a huge fleet with a five-thousandth team in heavy stormy conditions made many months of swimming between the mouths of the Indians and Euphrates. Byzantine merchants in the IV-VI centuries penetrated the East to India, and in the south - to Ethiopia and Arabia. Starting from the VII century, the Arab Sports began an intensive study of the Indian Ocean. They perfectly studied the coast of East Africa, Western and East India, Socotra, Java and Ceylon Islands, visited the Lakkadiv and Maldives, Islands of Sulawesi, Timor and others. 
At the end of the XIII century, the Venetian traveler Marco Polo on the way back from China passed through the Indian Ocean from Malacki to Ormuz Strait, visiting Sumatra, India, Ceylon. The journey was described in the "Book of the Diversity of the World", which had a significant impact on the navigators, cartographers, Writers of the Middle Ages in Europe. Chinese Junks made hiking along the Asian Coast of the Indian Ocean and reached the eastern shores of Africa (for example, Seven Jeneng Hoe Travels in 1405-1433). Expedition under the control of the Portuguese navalwater Vasco da Gama, having encouraged Africa from the south, passing along the Eastern coast of the continent in 1498, reached India. In 1642, the Dutch trading East India company organized an expedition from two ships under the command of Captain Tasman. As a result of this expedition, the central part of the Indian Ocean was investigated and it was proved that Australia is mainland. In 1772, the British expedition under the command of James Cook penetrated south of the Indian Ocean to 71 °. Sh., At the same time, extensive scientific material on hydrometeorology and oceanography was obtained.
From 1872 to 1876, the first scientific ocean expedition was held in the English sail-vapor Corway "Challenger", new data on the composition of the ocean, about the plant and animal worlds, about the rank of bottom and soil, was composed of the first map of the depths of the ocean and the first collection was collected deepwater animals. Around the World Expedition on the Russian Sail-Screw Corway "Vityaz" 1886-1889 under the leadership of the oceanographic scientist S. O. Makarov conducted a large-scale research work in the Indian Ocean. Oceanographic expeditions on the German courts "Walkiriya" (1898-1899) and Gauss (1901-1903) and Gauss (1901-1903) and Gauss (1901-1903) were made of a great contribution to the study of the Indian Ocean (1901-1903) (1930-1951). 1956-1958) and others. In 1960-1965, under the auspices of the intergovernmental oceanographic expedition, the International Indookean Expedition was held with UNESCO. She was the largest of all expeditions ever worked in the Indian Ocean. The program of oceanographic work covered observations almost the entire ocean, which contributed to the studies of scientists about 20 countries. Among them: Soviet and foreign scientists in the Research Courts "Vityaz", "A. I. Waikov "," Yu. M. Shokalsky, "Nemagnetic Schoon" Zarya "(USSR)," Natal "(South Africa)," Diamantina "(Australia)," Khtnaya "and" Varuna "(India)," Zulfikvar "(Pakistan). As a result, new valuable data on hydrology, hydrochemistry, meteorology, geology, geophysics and biology of the Indian Ocean were collected. Since 1972, regular deep-water drilling was carried out on the American ship "Glomar Challenger", work on the study of water masses at large depths, biological research.
In recent decades, numerous ocean measurements were carried out using space satellites. The result was released in 1994 by the American National Center for Geophysical Data Batymetric Oceans Atlas with 3-4 km permission and depth accuracy of ± 100 m.
Economic importance
Fishing and marine crafts
The value of the Indian Ocean for world fishing fishery is small: the catches here are only 5% of the total volume. The main fishing fish of the local water - tuna, Sardin, Cams, several types of sharks, barracudes and skates; Shrimps, lobsters and lobsters catch here. An even recently intense intense whaling intensity in the ocean is quickly cooled, due to the almost complete extermination of certain types of whales. In the North-West Bank of Australia, Pearls and Mother of Pearls are mined in Sri Lanka and Bahrain Islands. 
Transport routes
The most important transport routes of the Indian Ocean are routes from Persian Gulf to Europe, North America, Japan and China, as well as from the Aden Bay to India, Indonesia, Australia, Japan and China. The main shipping strands of the Indian Strait: Mozambique, Bab-El Mandant, Ormuz, Zondi. The Indian Ocean is connected by an artificial Suez Channel with the Mediterranean Sea of \u200b\u200bthe Atlantic Ocean. In the Suez Canal and the Red Sea converge and disagree all the most important freight traffic of the Indian Ocean. Large ports: Durban, Maputo (exportation: ore, coal, cotton, mineral raw materials, oil, asbestos, tea, raw sugar, cashew nuts, importation: Machines and equipment, industrial goods, food), Dar Es Salaam (export : Cotton, Coffee, Sizal, Diamonds, Gold, Petroleum products, Walnut Cashew, Carnation, Tea, Meat, Leather, Importation: Industrial products, Food, Chemicals), Jeddah, Salala, Dubai, Bender Abbas, Basra (export: oil, Grain, salt, dates, cotton, leather, import: machines, forest, textiles, sugar, tea), Karachi (exportation: cotton, fabric, wool, leather, shoes, carpets, rice, fish, import: coal, coke, petroleum products , mineral fertilizers, equipment, metals, grain, food, paper, jute, tea, sugar), Mumbai (export: manganese and iron ore, petroleum products, sugar, wool, leather, cotton, fabric, import: oil, coal, cast iron, Equipment, Grain, Chemicals, Industrial Goods), Colombo, Chennai (Iron Ore, Coal, Granite, Fertilizers, Petroleum products, Containers, Cars), Calcutta (exportation: Coal, Iron and copper ore, tea, importation: industrial goods, grain, food, equipment), chittagong (clothing, jute, leather, tea, chemicals), Yangon (export: rice, solid wood, non-ferrous metals, cake, legumes, rubber, Precious stones, importation: coal, machinery, food, fabrics), Perth Fremantle (export: ore, alumina, coal, coke, caustic soda, phosphoric raw materials, import: oil, equipment). 
Minerals
The most important minerals of the Indian Ocean are oil and natural gas. Their deposits are available on the shelves of the Persian and Suez bays, in the Bass Strait, on the shelf of the Peninsula of the Industan. On the coasts of India, Mozambique, Tanzania, South Africa, Madagascar Islands and Sri Lanka are operated by Ilmenit, monazit, rutile, titanite and zirconium. At the coast of India and Australia there are deposits of Barita and Phosphorita, and in the offshore zones of Indonesia, Thailand and Malaysia on an industrial scale, the deposits of Cassiiterite and Ilmenite are operated. 
Recreational resources
The main recreational zones of the Indian Ocean: the Red Sea, the west coast of Thailand, the island of Malaysia and Indonesia, Sri Lanka Island, the area of \u200b\u200bcoastal urban agglomerations of India, the east coast of Madagascar Island, Seychelles and Maldives. Among the countries of the Indian Ocean with the highest flow of tourists (according to the 2010 World Tourist Organization) are allocated: Malaysia (25 million visits per year), Thailand (16 million), Egypt (14 million), Saudi Arabia (11 million), South Africa (8 million), Arab Emirates (7 million), Indonesia (7 million), Australia (6 million), India (6 million), Qatar (1.6 million), Oman (1.5 million). 
(Visited 720 Times, 1 Visits Today)
Geographical position
Indian Ocean ranked third in the area and volume of water. It occupies 1/5 of the World Ocean Square and 1/7 of the surface of the planet (Fig. 1).
Fig. 1. Indian Ocean on the map.
Area Indian Ocean - 76.17 million km 2. Unlike the Pacific and Atlantic Ocean, it has a small number of seas, only 5. Temperature The surface layer of water is +17 ° C, and salinity - 36.5. The very saline part of the Indian Ocean is the Red Sea, salinity in 41. Relief Indian Ocean is peculiar: at the bottom of the ocean there are 10 main kitelins, 11 underwater ridges and 1 gutter in a depth of more than 6 thousand m.
Average depth Indian Ocean - 3711 m, and the maximum - 7729 m. The coastline of the Indian Ocean is very weakly cut. Remember the location of the objects of the Indian Ocean: the Red Sea (Fig. 3), the Aden Gulf, the Persian Bay (Fig. 2), the Arabian Sea, the Bengal Bay, the Archipelago Large Sunda Islands and the Mozambique Strait.
The most characteristic geographical feature of the Indian Ocean is that 84% of its area is in the southern hemisphere, and there is no direct connection with the Arctic Ocean.
Fig. 2. Persian Bay
Fig. 3. Red Sea
According to the modern data of the Western border of the Indian Ocean, the Meridian 20 ° C is served. D. on the segment between Antarctica and the needle needle in southern Africa. In the northeast, his border passes along the shores of Asia to the Malack Strait along the islands of Sumatra, Java, Timor, New Guinea. Further, in the east through Torres, the shed along the western coast of Australia and the island of Tasmania. Next, 147 ° C. D. To Antarctica. The southern border of the ocean is the coast of Antarctica from 20 ° C. d. up to 147 ° c. North border - South Coast of Eurasia.
History of Ocean Research
The shores of the Indian Ocean is one of the areas of ancient civilizations. The development of the ocean began with the north of Indian, Egyptian and Phoenician navigators, which for 3 thousand years before. e. Made a swimming in the Arabian and Red Seas and the Persian Bay. The first descriptions of swimming routes on the Indian Ocean were Arabs. For European geographic science information about the ocean began to accumulate since swimming time Vasco da Gama (1497-1499) (Fig. 4), which, having reached Africa, reached India.
In 1642-1643. Abel Tasman(Fig. 5) for the first time passed from the Indian Ocean in a quiet along the southern shores of Australia.
At the end of the XVIII century, the first probe depubs spent here James Cook(Fig. 6).
The complex and planned study of the ocean began at the end of the XIX century from the circular swimming of the English expedition on the Chellenger ship (Fig. 7).
However, by the middle of the 20th century, the Indian Ocean was studied very weakly. In the 50s. The Soviet Expedition began work on the "OB" vessel (Fig. 8).
Today, the Indian Ocean is studied by dozens of expeditions of different countries.
Lithospheric plates
At the bottom of the Indian Ocean there is a border of three lithospheric plates at once: African, Indo-Australian and Antarctic (Fig. 9). In the wpadine of the earth's crust, occupied by the waters of the Indian Ocean, all major structural reliefs of the ocean bottom are well expressed: shelf (its share accounts for more than 4% of the total area of \u200b\u200bthe ocean), the mainland slope, the ocean bed (oceanic plains and the basins, 56% of the whole area Ocean), mid-ocean ridges (17%), mountain arrays and underwater plateau, deep-water chute.
Fig. 9. Lithospheric plates on the map
The average and oceanic ridges divide the ocean bed into three large parts. The transition from the ocean's beds to the continents is smooth, only in the northeastern part there is an arc of the Sunda Islands, which is immersed by Indo-Australian lithospheric stove. In this place, a deep-water gutter for 4 thousand km is formed. Deep Zordsky Gutter, like underwater ridges, is a zone of active underwater volcanism and earthquakes.
Geological history of the ocean
Vpadina The Indian Ocean is very young. It formed about 150 million years ago as a result of the collapse of Gondwana and move away from each other, Africa, Australia, Antarctica and Industan. Close to modern outlines Indian Ocean acquired about 25 million years ago. Now the ocean is within three lithospheric plates: African, Indo-Australian and Antarctic.
Climate
The Indian Ocean is located in the tropical and subequatorial belts of the northern hemisphere, as well as in all climatic belts of the southern hemisphere. At surface temperatures, this is the warmest ocean. Temperature The Indian Ocean depends on the geographic latitude: the northern part of the ocean is warmer than the southern one. Also in the northern part of the Indian ocean monsoons are formed. The Indian Ocean ishes the coast of the biggest mainland - Eurasia. Their interaction determines the features of surface flows and circulation of the atmosphere over the northern part of the ocean and the southern coast of Asia. In winter, the area of \u200b\u200bhigh atmospheric pressure is formed over South Asia, and above the ocean - the area of \u200b\u200breduced pressure. Thus, the wind is formed - northeast monsoon. In the summer, on the other hand, the southwest monsoon is formed.
Navalois have long known to know the changeable nature of the winds and the flows of the northern part of the Indian Ocean and skillfully used it during a swimming vessels. Translated from the Arab "Musson" means "season of year", and "Breeze" translated from French - "light wind". Small sailing ships in the northern part of the Indian Ocean are still used.
Tsunami
Underwater earthquake in the Indian Ocean, which occurred December 26, 2004, caused a tsunami, which was recognized as the most deadly natural disaster in modern history. The earthquake magnitude, according to various sources, was from 9.1 to 9.3 points. This is the second or third earthquake in the history of observations. The epicenter of the earthquake was in the Indian Ocean north of the island of Symalue, located near the North-West Bank of Sumatra Island (Indonesia). Tsunami reached the coast of Indonesia, Sri Lanka, South of India, Thailand and other countries. The wave height exceeded 15 meters. Tsunami led to huge destruction and a huge number of dead people even in Port Elizabeth, South Africa, 6 thousand 900 km from the epicenter (Fig. 10).
Fig. 10. After the earthquake, December 2004
Died, by different estimates, from 225 to 300 thousand people. The true number of dead is unlikely to ever become known, since many people were taken by water in the sea.
Flora and fauna
Flora and fauna Indian Ocean is rather rich. Corals grow on shallow water of the tropical belt, which with red and green algae create islands. Among the coral islands are most famous Maldives(Fig. 11). There are many types of invertebrates among these strong coral structures, such as crabs, marine hedgehogs, sponges, coral fish. There are huge sections of thick thickets of brown algae. In the open ocean, mostly are plankton algae, and for the Arabian Sea are characterized by blue-green algae, which constantly become the cause of water flowering.
Fig. 11. Maldives
Also rich and animal world of the ocean. For example, among the animals of the Indian Ocean's animals are the most common races - coppeodes, as well as siforoforms and medusa. Squids live in the ocean, some types of bats, white shark, sailboat fish, poisonous sea snake, whales, turtles, seals (Fig. 12). Among the birds are the most common frigates and albatrosses.
Fig. 12. Underwater World of Indian Ocean
Flora and fauna of the Indian Ocean are very diverse and interesting, as animals and plants live in a favorable place for development. This is a flower garden for nature lovers, ecologists and tourists. In the shelf of the Indian Ocean, oil and natural gas are mined. The world's most famous oil production site is the Persian Bay. The Indian Ocean is considered the most contaminated oil compared to other oceans. Also in the Indian Ocean there is a lot of shipping pathways, there are large ports of ports and various places of recreation and tourism: Karachi, Dar Es Salaam, Maputo, Mumbai, etc.
Bibliography
1. Geography. Earth and people. Grade 7: Tutorial for general. Uch. / A.P. Kuznetsov, L.E. Savelyeva, V.P. Drones, series of "spheres". - M.: Enlightenment, 2011.
2. Geography. Earth and people. 7 CL.: Atlas, Series "Spheres".
1. Internet portal "Full Encyclopedia" ()
2. Internet portal "Geography" ()
3. Internet portal "All about sharks" ()