In the Indian Ocean, especially in the tropical part, the waters are inhabited large quantity variety of living organisms - from plankton to mammals. Phytoplankton are abundant unicellular algae trichodesmium, and zooplankton are represented by copepods, euphausids and diatoms. Mollusks are widespread (pteropods, scallops, cephalopods, etc.). Zoobenthos is also represented by echinoderms ( sea ​​stars, sea ​​urchins, holothurians and brittle stars), flint and lime sponges, bryozoans and crustaceans, and in the tropics and coral polyps.

At night, various luminous organisms are clearly visible in the water - peridinea, some types of jellyfish, ctenophores and tunicates. Brightly colored representatives of the hydroid class are very common, including such a poisonous representative of them as physalia.

The most numerous species of fish are the mackerel family (tuna, mackerel, mackerel), the dorado family, luminous anchovies - myctophids, Antarctic fish of the nototheniform suborder, flying fish, sailfish and many types of sharks. Dangerous inhabitants of the Indian Ocean include barracudas, moray eels and blue-ringed octopus.

Reptiles are represented by giant sea turtles and sea snakes, whose venom is more toxic than that of their land relatives. In the subpolar and temperate regions, cetaceans live - dolphins, whales (blue and toothless), killer whales and sperm whales. There are also mammals such as elephant seals and seals.

The islands of the Indian Ocean, as well as the Antarctic and South African coasts, are inhabited by penguins, frigates and albatrosses. There are also small endemic species on some islands - the frigatebird, the Seychelles owl, the paradise flycatcher, the shepherd's partridge, etc.

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The school course of the program in geography includes the study of the largest water areas - the oceans. This topic is quite interesting. Students are happy to prepare reports and abstracts on it. This article will provide information that contains a description of the geographical position of the Indian Ocean, its characteristics and features. So let's get started.

Brief description of the Indian Ocean

In terms of scale and quantity water reserves Indian Ocean comfortably located in third place, losing to the Pacific and Atlantic. A significant part of it is located on the territory of the Southern Hemisphere of our planet, and its natural aisles are:

• Southern part of Eurasia in the north.
• East coast of Africa in the west.
• Northern and northwestern coasts of Australia in the east.
• Northern part of Antarctica in the south.

In order to specify the exact geographical position Indian Ocean, you need a map. It can also be used during a presentation. So, on the world map, the water area has the following coordinates: 14°05′33.68″ south latitude and 76°18′38.01″ East longitude.

According to one version, the ocean in question was first called Indian in the work of the Portuguese scientist S. Munster called "Cosmography", which was published in 1555.

Characteristic

The total, taking into account all the seas included in its composition, is 76.174 million square meters. km, the depth (average) is more than 3.7 thousand meters, and the maximum was recorded at over 7.7 thousand meters.

The geographical position of the Indian Ocean has its own characteristics. Due to its large size, it is found in several climatic zones. It is also worth paying attention to the size of the water area. For example, the maximum width is between Linde Bay and the Toros Strait. The length from west to east is almost 12 thousand km. And if we consider the ocean from north to south, then the largest indicator will be from Cape Ras Jaddi to Antarctica. This distance is 10.2 thousand km.

Features of the water area

Studying the features of the geographical position of the Indian Ocean, it is necessary to consider its boundaries. First, note that the entire water area is located in Eastern Hemisphere. On the southwest side, it is bordered by Atlantic Ocean. In order to see this place on the map, you need to find 20 ° along the meridian in. e. Border with Pacific Ocean is located in the southeast. It runs along the 147° meridian east. e. With the North Arctic Ocean Indian not reported. Its border in the north is the most big mainland- Eurasia.

Structure coastline has a weak division. There are several large bays and 8 seas. There are relatively few islands. The largest are Sri Lanka, Seychelles, Curia-Muria, Madagascar, etc.

Bottom relief

The characterization will not be complete if you do not consider the features of the relief.

The Central Indian Ridge is an underwater formation located in the central part of the water area. Its length is about 2.3 thousand km. The width of the relief formation is within 800 km. The height of the ridge is more than 1 thousand meters. Some peaks protrude from the water, forming volcanic islands.

The West Indian Ridge is located in the southwestern part of the ocean. There is a lot of seismic activity here. The length of the ridge is about 4 thousand km. But in width it is less than the previous one by about half.

The Arabian-Indian Range is an underwater relief formation. It is located in the northwestern part of the water area. Its length is slightly less than 4 thousand km, and its width is about 650 km. At the end point (Rodriguez Island) it passes into the Central Indian Range.

The bottom of the Indian Ocean consists of sediments from the Cretaceous period. In some places, their thickness reaches 3 km. has a length of about 4500 km in length, and its width varies from 10 to 50 km. It's called Javanese. The depth of the depression is 7729 m (the largest in the Indian Ocean).

Climatic features

One of the most important circumstances in the formation of climate is the geographical position of the Indian Ocean relative to the equator. It divides the water area into two parts (the largest is in the south). Naturally, this arrangement affects temperature fluctuations and rainfall. The highest temperatures were recorded in the waters of the Red Sea and the Persian Gulf. Here, the average is a mark of +35 ° С. And in the southern point, the temperature can drop to -16 ° C in winter and up to -4 degrees in summer.

The northern part of the ocean is hot climate zone, thanks to which its waters are among the warmest in the oceans. Here it is mainly influenced by the Asian continent. Due to the current situation in the northern part, there are only two seasons - a hot rainy summer and a non-cold cloudless winter. As for the climate in this part of the water area, it practically does not change throughout the year.

Given the geographical position of the Indian Ocean, it is worth noting that its largest part is under the influence of air currents. From this we can conclude that the climate is mainly formed due to the monsoons. AT summer period over land, areas with low pressure are established, and over the ocean - with high pressure. During this season, the wet monsoon runs from west to east. In winter, the situation changes, and then the dry monsoon begins to dominate, which comes from the east and moves to the west.

In the southern part of the water area, the climate is more severe, since it lies in the subarctic zone. Here, the ocean is influenced by proximity to Antarctica. Off the coast of this continent, the average temperature is fixed at around -1.5 ° C, and the buoyancy limit of ice reaches 60 ° parallel.

Summing up

The geographical position of the Indian Ocean is very important question who deserves special attention. Due enough large sizes This area has many features. Along the coastline in huge number there are cliffs, estuaries, atolls, coral reefs. It is also worth noting such islands as Madagascar, Socotra, Maldives. They represent sections A Andaman, Nicobar descended from volcanoes that rose to the surface.

Having studied the proposed material, each student will be able to present an informative and interesting presentation.

The Indian Ocean is smaller in area than the Pacific. Its water area occupies 76 million square kilometers. It is located almost entirely in the southern hemisphere. AT ancient times people considered it a great sea.

The largest islands of the Indian Ocean are Sri Lanka, Madagascar, Masirai, Kuria Muria, Socotra, Greater Sunda, Seychelles, Nicobar, Andanam, Coconut, Amirant, Chagos, Maldives, Laccadive.

The coast of the Indian Ocean - the places where ancient civilizations were located. Scientists believe that navigation in this ocean began earlier than in others, about 6 thousand years ago. The first to describe ocean routes were the Arabs. The accumulation of navigational information about the Indian Ocean began as early as the travels of Vasco de Gama (1497-1499). AT late XVIII centuries, the first measurements of its depths were carried out English navigator James Cook.

Detailed study of the ocean began in late XIX century. The most extensive study was carried out by the English research group on board the Challenger. AT this moment, dozens of research expeditions from different states study the nature of the ocean, revealing its wealth.

The average depth of the Indian Ocean is about 3,700 meters, and the maximum is 7,700 meters. Seamounts are located in the western part of the ocean, connecting in a place located south of the cape Good Hope, with the Mid-Atlantic Ridge. Near the center of the ridge in the Indian Ocean are deep faults, areas seismic activity and volcanic eruptions at the bottom of the ocean. These faults stretch to the Red Sea and come out on land. The bottom of the ocean is crossed by numerous hills.

If the Pacific Ocean inspires with its blue color, then the Indian Ocean is known for the transparency of its dark blue and azure waters. This is due to the cleanliness of the ocean, as little fresh water from the rivers - "disturbers of purity", especially in its southern part.

The Indian Ocean is saltier than other oceans. This is especially noticeable in the northwestern part of the ocean, where high temperatures hot water is added air masses from the Sahara. The record holder for salt content is the Red Sea (up to 42%) and the Persian Gulf.

The northern part of the Indian Ocean is under great influence sushi; it rightfully deserves the name "monsoon sea". AT winter time dry air comes from largest continent- Eurasia. In summer, the situation changes dramatically. The heated ocean saturates the air with a large amount of moisture. Then, moving to the mainland, it breaks out over the south of the continent with heavy rains. Before the summer monsoon winds, thunderstorms pass, generating sea swell, carried by the wind to the southwestern coast of India. In autumn and spring, typhoons form in the northern part of the Indian Ocean, bringing many problems to the inhabitants of the shores of the Arabian Sea and the Bay of Bengal, as well as to sailors. In the south of the Indian Ocean, you can feel the cold breath of Antarctica, in these places the ocean is the most severe.

Indian Ocean forms good conditions for coral life. Their large colonies are located in the Maldives, located south of the Hindustan peninsula. These islands are by composition the longest coral islands in the world.

The Indian Ocean is rich in its fish resources, which have been used by man since ancient times. For many residents of the coast, fishing is the only source of income.

Since time immemorial, pearls have been mined in these places. The coast of the island of Sri Lanka since ancient times served as a place for the extraction of emeralds, diamonds, emeralds and many other types of precious stones.

Under the bottom of the Persian Gulf, located in the northwestern part of the Indian Ocean, gas and oil reserves have been formed for thousands of years.

AND . Here, the boundaries between the oceans are conventionally drawn from southern tip Africa - the Cape of Good Hope along 20 ° E. and from the southern tip along 147 ° E. e. The most difficult boundary of the Indian Ocean is in the northeast, where it runs along the northern part of the Strait of Malacca, the southwestern and southern shores of the Greater and Lesser Sunda Islands, the southwestern coast of Novaya and the Torres Strait.

There are relatively few seas in the Indian Ocean - the Red, Andaman, Timor, Arafura and others. There are also few islands. They are concentrated mainly in the western part of the ocean. The largest - Tasmania, Socotra - are of mainland origin. The rest of the islands are small and are either above-water peaks of volcanoes or coral atolls - Chagos, Laccadive, Amirantsky, etc. There are also volcanic islands bordered by coral reefs - Mascarene, Comoros, Andaman, Nicobar. Special place occupy: within the ocean bed it is sole education composed of granites, i.e., belonging to the continental type.

Unlike the Pacific and Atlantic, the Indian Ocean does not go far to the north and does not connect with.

Indian Ocean is one of the areas ancient civilizations. It began to be mastered by the peoples who inhabited its shores as early as four millennia BC. And yet, until recently, it remained one of the least explored oceans. Only in the last 25-30 years has the situation changed dramatically. In conditions modern life significantly increased the role of the Indian Ocean in international arena, which is largely due to its rich natural and human resources (more than 2 billion people). By different directions it has shipping lanes connecting the world's largest ports. The Indian Ocean accounts for 17-18% of the port cargo turnover of the capitalist countries. Most major ports are , Madras, Colombo, Port Elizabeth, Aden, Basra, Daman.

Geological structure bottom and the most important features of the relief. Within the Indian Ocean, the underwater margin of the continents, the ocean floor, mid-ocean ridges and a very insignificant transition zone are distinguished.

Underwater. Despite the small width of the shelf (7-80 km), the underwater margin of the continents within the Indian Ocean occupies a significant area, which is associated with the spread of marginal plateaus.

The entire shelf is the Persian Gulf with a depth of 100 m and a bottom leveled by accumulative processes. In the structure of the narrow shelf also big role plays alluvial material. In the northern part of the Bay of Bengal, there is an accumulation of strata of terrigenous material carried into the Ganges and Brahmaputra Seas, so the shelf here is also not wide. The shelf is wide. From a depth of 100-200 m, a narrow continental slope begins, in some places dissected by underwater canyons, of which the most impressive are canyons and the Ganges. At a depth of 1000-1500 m, the continental slope gives way to the continental foot, where there are extensive (up to several hundred kilometers wide) fans of turbidity flows, forming an inclined plain.

Underwater margin African mainland also has a narrow shelf. The narrow and steep continental slope is characteristic of the coast and the Mozambique Channel. Numerous submarine canyons off the coast of Africa serve as paths for turbidity flows, which form a relatively clearly defined wide continental foot. The bottom of the Mozambique Channel is composed of continental-type crust, which indicates a relatively recent separation from Africa due to the subsidence of the platform.

shelf area Australian platform characterized by a wide development of coral structures. In the Bass Strait area, the shelf relief has a structural-denudation character. The continental slope is very gentle, furrowed with canyons. The transition of the slope to the continental foot is not clearly expressed.

transition zone. The transition zone in the Indian Ocean occupies a little more than 2% of the total ocean area and is represented by only a part of the Indonesian transition region. A pronounced element of this area is the Sunda (Yavansky) deep-water trench (7729 m). It can be traced to the northern part of the Bay of Bengal and reaches a length of 4000 km. To the north and northeast of it is the outer island arc of the Sunda Islands, which begins in the north with the Andaman Islands and continues with the Nicobar Islands. South of the island The outer arc of Sumatra becomes entirely underwater, and then the islands rise again above the surface of the ocean in the form of the islands of Sumba and Timor. Along the island of Timor, a small trough up to 3300 m deep appears again. Behind the outer arc, the Bali depression extends parallel to it, up to 4850 m deep, separating from the outer inner island arc, which consists of the large islands of Sumatra, Java, Bali. The role of the island arc in Sumatra and Java is played by their volcanic ridges external to the Indian Ocean. And part of the same islands, facing the South China and Java Seas, are accumulative lowlands with a continental type earth's crust. Active are characterized, where there are 95 volcanoes, of which 26 are active. The most famous is Krakatau.

mid-ocean ridges. The Indian Ocean is represented by a system of mid-ocean ridges, which form the basis of the frame of the bottom of the Indian Ocean.

In the southwest of the ocean, the West Indian Ridge begins, which strikes northeast and is characterized by all the signs of rifting (high, underwater volcanism, rift structure of the ridge). On the east slope The ridge contains two large volcanic massifs protruding above the water. Their peaks form Prince Edward and Crozet Islands. In the area of ​​​​Rodrigues Island, at a latitude of about 20 ° S. sh., the West Indian Range connects with the Arabian-Indian.

The Arabian-Indian ridge has been studied quite fully. The rift structure of the ridge zone is clearly expressed in it, seismicity is high, and ultramafic ones come to the bottom surface. In the north, the Arabian-Indian ridge takes on an almost latitudinal strike and is replaced by rift-block structures of the bottom of the Gulf of Aden. In the western part of the Gulf of Aden, the rift system bifurcates and forms two branches. The southern branch invades the African continent in the form of East African rifts, and the northern branch is formed by rifts, the Gulf of Aqaba, Dead Sea. AT central regions In the Red Sea, powerful outcrops of hot (up to + 70 ° C) and extremely saline (up to 300% o) waters were found at great depths.

The next link in the system of mid-ocean ridges is the Central Indian Ridge. It stretches from the island of Rodrigues, i.e., from the junction of the West Indian and Arabian-Indian ridges, southeast to the islands of Amsterdam and St. Paul, where the Amsterdam Fault separates it from another link in the mid-ocean system in the Indian Ocean - Australo-Antarctic Rise.

Australo-Antarctic Rise morphological features closest to the mid-ocean rises of the Pacific Ocean. This is a wide swell-like elevation of the ocean floor with a predominance of low-mountain and hilly relief. Most of the rise rift zones missing.

In the east and southeast of the ocean, the system of mid-ocean ridges is represented by the Mascarene, Mozambique, and Madagascar ridges.

Another major ridge in the Indian Ocean is the East Indian. It stretches from about 32° S. sh. almost meridional to the Bay of Bengal and has a length of 5000 km. This is a narrow mountain uplift, broken by longitudinal faults. Against its middle part in eastbound the rise of the Cocos Islands, represented by several volcanic cones, departs. The peaks of the Cocos Islands are covered with coral atolls. Here is located Christmas Island, which is an uplifted ancient atoll with absolute altitude 357 m.

From the southern margin of the East Indian Ridge, almost in a latitudinal direction to the east, the West Australian Ridge departs, consisting of plateau-like uplifts and sharply pronounced ridges. According to many American scientists, it is composed of continental-type crust up to 20 km thick. On the slopes of the ridge, fragments of dolerites similar to those of the island of Tasmania were found.

Ocean bed. The system of numerous ridges and uplifts divides the bed of the Indian Ocean into 24 basins, of which the largest are Somali, Mascarene, Madagascar, Mozambique, Central, Cocos, West, South Australian, African-Antarctic, etc. The deepest of them are Amsterdam (7102 m), African-Antarctic (6972 m), Western Australian (6500 m), Madagascar (6400 m). The relief of the bottoms of the basins is presented with small-hilly and small-block dissection, as well as plains with large-hilly and large-block dissection.

As in the Pacific Ocean, faults with submeridional and meridional strikes play an important role in the bed of the Indian Ocean. Faults of sublatitudinal and latitudinal strike are less common.

The bed of the Indian Ocean is characterized by hundreds of separate underwater mountain peaks. The most significant among them are: a mountain in the Central Basin, Mount Shcherbakov in the Western Australian Basin. In the Arabian Sea in 1967, a seamount was discovered, called the mountain of Moscow State University, with a characteristic flat top, which makes it similar to the guyots of the Atlantic and Pacific Oceans.

Bottom sediments. The bottom sediments of low latitudes are dominated by carbonate foraminiferal silt. It occupies more than half of the ocean floor area. Red clay and radiolarian silt occur at the greatest depths, and coral deposits occur at shallower depths. Along Antarctica, diatom oozes are traced in a wide strip, and iceberg deposits are traced near the continent itself.

Position of the Indian Ocean
Or where is the Indian Ocean

First of all, the Indian Ocean is the youngest on Earth. It is located mainly in southern hemisphere. Four continents surround it. In the north - Asian part Eurasia, Africa in the west, Australia in the east and Antarctica in the south. Along the line from Cape Agulhas, the most southern point Africa, and along the twentieth meridian to Antarctica, its waves merge with the Atlantic. The Indian Ocean borders the Pacific Ocean to the north of West Bank the Malay Peninsula to northern point the islands of Sumatra and further along the islands of Sumatra, Java, Bali, Sumba, Timor and New Guinea. About eastern border there was a lot of controversy among geographers. But now everyone seems to have agreed to count it from Cape York in Australia, through the Torres Strait, New Guinea and further northeast through the Lesser Sunda Islands to the islands of Java, Sumatra and the city of Singapore. Between the islands of New Guinea and Australia, its border runs along the Torres Strait. In the south, the ocean border runs from Australia to west coast the islands of Tasmania and further along the meridian to Antarctica. Thus, when viewed from space, The Indian Ocean is shaped like a triangle…

What is the area of ​​the Indian Ocean?

The Indian Ocean is the third largest after the Pacific and Atlantic (), its area is 74,917 thousand square kilometers.

Seas of the Indian Ocean

The shores of the bordering continents are slightly indented, therefore there are very few seas in it - in the north it is the Red Sea, the Persian Gulf, the Arabian Sea, the Bay of Bengal and the Andaman Sea, and in the east - the Timor and Arafura Seas.

Depth of the Indian Ocean

At the bottom of the Indian Ocean, in its central part, there are several deep-water basins separated by underwater ridges and underwater plateaus, and along the Sunda island arc there is deep water Sunda Trench. In it, oceanologists have found the most deep hole on the ocean floor - 7130 meters from the surface of the water. The average depth of the ocean is 3897 meters. Most major islands in the Indian Ocean - Madagascar, Socotra and Sri Lanka. All of them are fragments of ancient continents. In the central part of the ocean there are groups of small volcanic islands, and in tropical latitudes there are quite a lot of coral islands.

Temperature of the Indian Ocean

The water in the Indian Ocean is warm. In June - August, closer to the equator, its temperature, as in a bath, is 27-28 ° C (and there are places where the thermometer shows 29 ° C). And only off the coast of Africa, where the cold Somali current passes, the water is colder - 22-23 ° С. But from the equator south to the Antarctic, the temperature of the water in the ocean changes to 26 and even 28 ° C. From the north, it is limited by the shores of the Eurasian continent. From South - conditional line connecting the ends South Africa and Australia. West is Africa.

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But why is the Indian Ocean considered the youngest? On the geographical map it is clearly visible how its basin is surrounded by continental land areas. In the not so distant geological past of our planet, these areas were most likely connected into a single continent Gondwana, which split, and its parts blurred into different sides making room for water.

At the bottom of the Indian Ocean, scientists have discovered several underwater mountain ranges. And The Central Indian Range divides the ocean basin into two regions. with absolutely different types earth's crust. Deep cracks adjoin the seamounts. Such proximity inevitably causes frequent earthquakes in these areas, or rather, seaquakes. As a result, tsunamis are born, which bring incalculable troubles to island and coastal mainland residents.

Submarine volcanoes in these restless regions eject so much material from the bowels that new islands appear from time to time. Many coral reefs and atolls are found in the local warm waters. Driving ships in the Indian Ocean is not easy. During stormy periods, in some of its areas, huge waves as high as a five-story building were registered! .. Giant catastrophic waves tsunamis are not such a rare exotic for the inhabitants of the Indian Ocean basin.