Introduction
1.History of the formation and exploration of the Indian Ocean
2.General information about the Indian Ocean
Bottom relief.
.Characteristics of the waters of the Indian Ocean.
.Bottom sediments of the Indian Ocean and its structure
.Minerals
.Climate of the Indian Ocean
.vegetable and animal world
.Fishing and marine industry
Introduction
Indian Ocean - the youngest and warmest among the world's oceans. Most of it is in the southern hemisphere, and in the north it goes far into the mainland, which is why ancient people considered it just a big sea. It was here, in the Indian Ocean, that man began his first sea voyages.
The largest rivers of Asia belong to the Indian Ocean basin: the Salween, the Irrawaddy and the Ganges with the Brahmaputra, which flow into the Bay of Bengal; the Indus, which flows into the Arabian Sea; Tigris and Euphrates, merging a little above the confluence with the Persian Gulf. Of the major rivers of Africa, which also flow into the Indian Ocean, the Zambezi and Limpopo should be mentioned. Because of them, the water off the coast of the ocean is cloudy, with a high content sedimentary rocks- sand, silt and clay. But the open waters of the ocean are amazingly clear. The tropical islands of the Indian Ocean are famous for their cleanliness. A variety of animals have found their place on coral reefs. The Indian Ocean is home to the famous sea devils, rare whale sharks, bigmouths, sea cows, sea snakes, etc.
1. History of formation and research
Indian Oceanformed at the junction of the Jurassic and Cretaceous periods as a result of the collapse of Gondwana (130-150 million years ago). Then there was a separation of Africa and the Deccan from Australia with Antarctica, and later - Australia from Antarctica (in the Paleogene, about 50 million years ago).
The Indian Ocean and its shores remain poorly explored. The name of the Indian Ocean is found already at the beginning of the 16th century. Schöner under the name Oceanus orientalis indicus, in contrast to the Atlantic Ocean, then known as Oceanus occidentalis. Subsequent geographers called the Indian Ocean for the most part by the sea of India, some (Varenius) by the Australian Ocean, and Fleurie recommended (in the 18th century) to call it even the Great Indian Gulf, considering it as part of the Pacific Ocean.
In ancient times (3000-1000 BC), sailors from India, Egypt and Phoenicia traveled across the northern part of the Indian Ocean. The first navigation charts were compiled by the ancient Arabs. At the end of the 15th century, the first European, the famous Portuguese Vasco da Gama, circled Africa from the south and entered the waters of the Indian Ocean. By the 16th-17th centuries, Europeans (the Portuguese, and later the Dutch, French and British) increasingly appeared in the Indian Ocean basin, and by the middle of the 19th century, most of its coasts and islands were already the property of Great Britain.
Discovery historycan be divided into 3 periods: from ancient voyages to 1772; from 1772 to 1873 and from 1873 to the present. The first period is characterized by the study of the distribution of ocean and land waters in this part the globe. It began with the first voyages of Indian, Egyptian and Phoenician navigators, who, in 3000-1000 BC. traveled through the northern part of the Indian Ocean, and ended with the voyage of J. Cook, who in 1772-75 penetrated south to 71 ° S. sh.
The second period was marked by the beginning of deep-sea research, first carried out by Cook in 1772 and continued by Russian and foreign expeditions. The main Russian expeditions were - O. Kotzebue on the "Rurik" (1818) and Pallen on the "Cyclone" (1858-59).
The third period is characterized by complex oceanographic research. Until 1960 they were carried out on separate ships. The largest work was carried out by expeditions on the ships Challenger (English) in 1873-74, Vityaz (Russian) in 1886, Valdivia (German) in 1898-99 and Gauss (German) in 1901-03, "Discovery II" (English) in 1930-51, the Soviet expedition to the "Ob" in 1956-58, etc. In 1960-65, the Intergovernmental Oceanographic Expedition under UNESCO conducted an international Indian Ocean expedition, which collected new valuable data on hydrology, hydrochemistry, meteorology , geology, geophysics and biology of the Indian Ocean.
. General information
Indian Ocean- the third largest ocean of the Earth (after the Pacific and Atlantic), covering about 20% of its water surface. Almost all of it is in the southern hemisphere. Its area is 74917 thousand km ² ; average volume of water - 291945 thousand km ³. In the north it is bounded by Asia, in the west by the Arabian Peninsula and Africa, in the east by Indochina, the Sunda Islands and Australia, in the south by the Southern Ocean. border between Indian and Atlantic Ocean runs along the 20° meridian east longitude (Meridian of the Cape of Needles), between the Indian and Pacific Oceans runs along the 147 ° meridian of east longitude (meridian of the southern cape of the island of Tasmania). The northernmost point of the Indian Ocean is located at approximately 30° north latitude in the Persian Gulf. The width of the Indian Ocean is approximately 10,000 km between the southern points of Australia and Africa.
The greatest depth of the Indian Ocean is the Sunda, or Java Trench (7729 m), the average depth is 3700 m.
The Indian Ocean washes three continents at once: Africa from the east, Asia from the south, Australia from the north and northwest.
The Indian Ocean has the fewest seas compared to other oceans. In the northern part are located the most large seas: Mediterranean - the Red Sea and the Persian Gulf, the semi-enclosed Andaman Sea and the marginal Arabian Sea; in the eastern part - the Arafura and Timor seas.
In the Indian Ocean, there are the island states of Madagascar (the fourth largest island in the world), Sri Lanka, the Maldives, Mauritius, the Comoros, and the Seychelles. The ocean washes in the east such states: Australia, Indonesia; in the northeast: Malaysia, Thailand, Myanmar; in the north: Bangladesh, India, Pakistan; in the west: Oman, Somalia, Kenya, Tanzania, Mozambique, South Africa. In the south it borders on Antarctica. There are relatively few islands. In the open part of the ocean, there are volcanic islands - Mascarene, Crozet, Prince Edward, etc. In tropical latitudes, coral islands rise on volcanic cones - Maldives, Laccadive, Chagos, Cocos, most of the Andaman, etc.
. Bottom relief
The ocean floor is a system of mid-ocean ridges and basins. In the region of Rodrigues Island (Mascarene Archipelago) there is a so-called triple junction, where the Central Indian and West Indian ridges converge, as well as the Australo-Antarctic Rise. The ridges consist of steep mountain ranges cut by normal or oblique faults with respect to the axes of the chains and divide the basalt ocean floor into 3 segments, and their tops are, as a rule, extinct volcanoes. The bottom of the Indian Ocean is covered with deposits of the Cretaceous and later periods, the thickness of which varies from several hundred meters to 2-3 km. The deepest of the numerous trenches of the ocean is the Yavan (4,500 km long and 29 km wide). The rivers flowing into the Indian Ocean carry with them huge amounts of sedimentary material, especially from the territory of India, creating high alluvial rapids.
The coast of the Indian Ocean is replete with cliffs, deltas, atolls, coastal coral reefs and salt marshes overgrown with mangroves. Some islands - for example, Madagascar, Socotra, Maldives - are fragments of ancient continents. Numerous islands and archipelagos of volcanic origin are scattered in the open part of the Indian Ocean. In the northern part of the ocean, many of them are crowned with coral structures. Andaman, Nicobar or Christmas Island - are of volcanic origin. The Kerguelen Plateau, located in the southern part of the ocean, also has a volcanic origin.
An underwater earthquake in the Indian Ocean on December 26, 2004 triggered a tsunami, which was recognized as the deadliest natural disaster in modern history. The magnitude of the earthquake was, according to various estimates, from 9.1 to 9.3. This is the second or third strongest earthquake on record.
The epicenter of the earthquake was located in the Indian Ocean, north of the island of Simeulue, located near the northwestern coast of the island of Sumatra (Indonesia). The tsunami reached the shores of Indonesia, Sri Lanka, southern India, Thailand and other countries. The height of the waves exceeded 15 meters. The tsunami caused massive destruction and a huge number of dead people, even in Port Elizabeth, in South Africa, 6900 km from the epicenter. Died, according to various estimates, from 225 thousand to 300 thousand people. true number the dead are unlikely to ever be known, as many people were carried away by the water into the sea.
With regard to the properties of the bottom soil, then, like in other oceans, sediments on the bottom of the Indian Ocean can be divided into three classes: coastal sediments, organic silt (globigerine, radiolar or diatom) and special clay great depths, the so-called red clay. Coastal sediments are sand, located mostly on coastal shallows to a depth of 200 meters, green or blue silt near rocky coasts, brown in volcanic areas, but lighter and sometimes pinkish or yellowish near coral coasts due to the lime prevailing here. Globigerin silt, consisting of microscopic foraminifers, covers the deeper parts of the ocean floor almost to a depth of 4500 m; south of parallel 50°S sh. calcareous foraminiferal deposits disappear and are replaced by microscopic siliceous, from the group of algae, diatoms. With regard to the accumulation of diatom remains on the bottom, the southern part of the Indian Ocean is especially different from other oceans, where diatoms are found only in places. Red clay occurs at depths greater than 4500 m; it has the color red, or brown, or chocolate.
indian ocean climate fossil fishery
4. Characteristics of waters
Surface water circulationin the northern part of the Indian Ocean it has a monsoonal character: in summer - northeast and east currents, in winter - southwest and west currents. AT winter months between 3° and 8° S sh. an inter-trade (equatorial) countercurrent develops. In the southern part of the Indian Ocean, water circulation forms an anticyclonic circulation, which is formed from warm currents- South Tradewind in the North, Madagascar and Needle in the West and cold - currents of the West Winds in the South and West Australian in the East South of 55 ° S. sh. several weak cyclonic water cycles develop, closing off the coast of Antarctica with an easterly current.
Belt of the Indian Oceanbetween 10 ° with. sh. and 10 ° Yu. sh. called the thermal equator, where the surface water temperature is 28-29°C. To the south of this zone, the temperature drops, reaching ?1°C off the coast of Antarctica. In January and February, the ice along the coast of this continent melts, huge blocks of ice break off from the ice sheet of Antarctica and drift towards the open ocean. To the north, the temperature characteristics of the waters are determined by the monsoon air circulation. In summer, temperature anomalies are observed here, when the Somali Current cools surface water up to a temperature of 21-23°C. In the eastern part of the ocean at the same geographical latitude, the water temperature is 28 ° C, and the highest temperature mark - about 30 ° C - was recorded in the Persian Gulf and the Red Sea. The average salinity of ocean waters is 34.8‰. The most saline waters of the Persian Gulf, the Red and Arabian Seas: this is due to intensive evaporation with a small amount of fresh water brought into the seas by rivers.
Tides in the Indian Ocean, as a rule, are small (near the coast of the open ocean and on the islands from 0.5 to 1.6 m), only at the tops of some bays they reach 5-7 m; in the Gulf of Cambay 11.9 m. The tides are predominantly semi-diurnal.
Ice forms at high latitudes and is carried by winds and currents along with icebergs in a northerly direction (up to 55 ° S in August and up to 65-68 S in February).
. Bottom sediments of the Indian Ocean and its structure
Bottom sedimentsthe Indian Ocean have the greatest thickness (up to 3-4 km) at the foot of the continental slopes; in the middle of the ocean - small (about 100 m) thickness and in places where the dissected relief is distributed - discontinuous distribution. The most widely represented are foraminiferal (on the continental slopes, ridges and at the bottom of most basins at a depth of up to 4700 m), diatoms (south of 50 ° S), radiolarian (near the equator) and coral sediments. Polygenic sediments - red deep-sea clays - common south of the equator at a depth of 4.5-6 km or more. Terrigenous sediments - off the coast of the continents. Chemogenic sediments are mainly represented by ferromanganese nodules, while riftogenic sediments are represented by destruction products of deep rocks. Outcrops of bedrocks are most often found on continental slopes (sedimentary and metamorphic rocks), mountains (basalts) and mid-ocean ridges, where, in addition to basalts, serpentinites and peridotites have been found, representing little-altered matter of the Earth's upper mantle.
The Indian Ocean is characterized by the predominance of stable tectonic structures both on the bed (thalassocratons) and along the periphery (continental platforms); active developing structures - modern geosynclines (Sonda arc) and georiftogenals (mid-ocean ridge) - occupy smaller areas and continue in the corresponding structures of Indochina and rifts of East Africa. These main macrostructures, which differ sharply in morphology, the structure of the earth's crust, seismic activity, and volcanism, are subdivided into smaller structures: plates, usually corresponding to the bottom of oceanic basins, blocky ridges, volcanic ridges, sometimes topped with coral islands and banks (Chagos, Maldives, etc.). .), trench-faults (Chagos, Ob, etc.), often confined to the foot of blocky ridges (East Indian, West Australian, Maldives, etc.), fault zones, tectonic ledges. Among the structures of the bed of the Indian Ocean special place(according to the presence of continental rocks - granites of the Seychelles and the continental type of the earth's crust) occupies the northern part of the Mascarene Range - a structure that, apparently, is part of the ancient mainland of Gondwana.
. Minerals
The most important minerals of the Indian Ocean are oil and natural gas. Their deposits are found on the shelves of the Persian and Suez Gulfs, in the Bass Strait, on the shelf of the Hindustan Peninsula. In terms of reserves and production of these minerals, the Indian Ocean ranks first in the world. On the coasts of Mozambique, the islands of Madagascar and Ceylon, ilmenite, monazite, rutile, titanite and zirconium are exploited. There are deposits of barite and phosphorite off the coast of India and Australia, and deposits of cassiterite and ilmenite are exploited on an industrial scale in the shelf zones of Indonesia, Thailand and Malaysia. On the shelves - oil and gas (especially the Persian Gulf), monazite sands (the coastal region of Southwestern India), etc.; in reef zones - ores of chromium, iron, manganese, copper, etc.; on the bed - huge accumulations of ferromanganese nodules.
. Climateindian ocean
Most of The Indian Ocean is located in warm climatic zones - equatorial, subequatorial and tropical. Only its southern regions, located at high latitudes, are strongly influenced by Antarctica. The equatorial climate zone of the Indian Ocean is characterized by a constant predominance of humid warm equatorial air. Average monthly temperatures range here from 27° to 29°. The water temperature is slightly higher than the air temperature, which creates favorable conditions for convection and precipitation. Their annual amount is large - up to 3000 mm and more.
. Flora and fauna
The most dangerous mollusks in the world live in the Indian Ocean - cone snails. Inside the snail there is a rod-like container with poison, which it injects into its prey (fish, worms), its poison is also dangerous for humans.
The entire water area of the Indian Ocean lies within the tropical and southern temperate zones. The shallow waters of the tropical zone are characterized by numerous 6- and 8-ray corals, hydrocorals, capable of creating islands and atolls together with calcareous red algae. The richest fauna of various invertebrates (sponges, worms, crabs, mollusks, sea urchins, ophiurs and sea stars), small but brightly colored coral fish. Most of the coasts are occupied by mangroves, in which the mudskipper stands out - a fish capable of long time exist in the air. The fauna and flora of the beaches and rocks that dry out at low tide are quantitatively depleted as a result of the depressing effect of the sun's rays. In the temperate zone, life on such stretches of coasts is much richer; dense thickets of red and brown algae (kelp, fucus, reaching the huge size of microcystis) develop here, various invertebrates are abundant. For the open spaces of the Indian Ocean, especially for the surface layer of the water column (up to 100 m), rich flora is also characteristic. Of the unicellular planktonic algae, several species of peredinium and diatom algae predominate, and in the Arabian Sea - blue-green algae, often causing the so-called water bloom during mass development.
The bulk of the ocean's animals are copepods (more than 100 species), followed by pteropods, jellyfish, siphonophores, and other invertebrates. Of the unicellular, radiolarians are characteristic; numerous squids. Of the fish, the most abundant are several species of flying fish, luminous anchovies - myctophids, dolphins, large and small tuna, sailfish and various sharks, poisonous sea snakes. Sea turtles and large marine mammals (dugongs, toothed and toothless whales, pinnipeds) are common. Among the birds, the most characteristic are albatrosses and frigatebirds, as well as several species of penguins that inhabit the coast. South Africa, Antarctica and islands lying in the temperate zone of the ocean.
At night, the surface of the Indian Ocean shimmers with lights. Light is produced by small marine plants called dinoflagellates. Luminous areas sometimes have the shape of a wheel with a diameter of 1.5 m.
. Fishing and marine industry
Fishing is underdeveloped (the catch does not exceed 5% of the world catch) and is limited to the local coastal zone. Near the equator (Japan) is fishing for tuna, and in Antarctic waters - whale fishing. In Sri Lanka, on the Bahrain Islands and on the northwestern coast of Australia, pearls and mother-of-pearl are mined.
The countries of the Indian Ocean also have significant resources of other valuable species mineral raw materials (tin, iron and manganese ores, natural gas, diamonds, phosphorites, etc.).
Bibliography:
1.Encyclopedia "Science" Dorling Kindersley.
.“I know the world. Geography” V.A. Markin
3.slovari.yandex.ru ~ TSB books / Indian Ocean /
4.Big Encyclopedic Dictionary of Brockhaus F.A., Efron I.A.
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Indian Ocean is the warmest ocean on our planet. Occupying a fifth of the Earth's surface, the Indian Ocean is not the largest ocean, but it has rich flora and fauna, as well as a host of other advantages.
Indian Ocean
Indian Ocean occupies 20% of the world. This ocean is characterized by a rich and varied natural life. 
shows vast areas and a large number of interesting islands for explorers and tourists. If you still don't know where Indian Ocean, map will prompt you.
Map of the currents of the Indian Ocean
Underwater world of the Indian Ocean
Rich and varied underwater world of the indian ocean. In it you can meet both very small aquatic inhabitants, and large and dangerous representatives of the aquatic world.
Since ancient times, man has been trying to subjugate the ocean and its inhabitants. Throughout the ages, the inhabitants of the underwater world of the Indian Ocean have been hunted.
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There are even those that can cause trouble to a person. For example, these are anemones that live in almost all the seas and oceans of our planet. Sea anemones can be found not only in the depths, but also in the shallow waters of the Indian Ocean. They almost always feel hungry, so they sit lurking with widely spaced tentacles. Predatory representatives of this species are poisonous. Their shot can hit small organisms, as well as cause burns to people. Sea urchins, seals, the most exotic species of fish live in the waters of the Indian Ocean. Vegetable world diverse, which makes diving truly exciting.
Fish in the Indian Ocean
The message about the Indian Ocean will briefly tell you about the ocean, which is the third largest after the Pacific and Atlantic oceans. You can also use the report on the Indian Ocean to prepare for the lesson.
Message about the Indian Ocean
Indian Ocean: geographical location
The Indian Ocean is located in the Eastern Hemisphere. It is bounded by Eurasia in the northeast and north, Africa in the west, the Antarctic Convergence Zone in the southeast, the east coast of Africa in the south, and the west coast of Oceania and Australia in the east. This ocean is the third largest after the Atlantic and Pacific oceans. Its area is 76.2 million km 2, and the volume of water is 282.6 million km 3.
Features of the Indian Ocean
It was from the Indian Ocean that the study of water expanses began. Of course, the population of the most ancient civilizations did not swim far into open waters and considered the ocean to be a huge sea. The Indian Ocean is quite warm: the water temperature near the coast of Australia is +29 0 С, in the subtropics +20 0 С.
In this ocean, unlike other oceans, a small number of rivers flow. Mostly in the north. The rivers carry a large amount of sedimentary rocks into it, so the northern part of the ocean is quite polluted. The southern part of the Indian Ocean is much cleaner, as there are no freshwater arteries. Therefore, the water is crystal clear with a dark, blue tint. It is the lack of desalination and large evaporation that is the reason that the salinity of the Indian Ocean is much higher than in other oceans. The most salty part of the Indian Ocean is the Red Sea. Its salinity is 42% 0. Also, the salinity of the ocean is affected by icebergs, which swim far inland. Up to 40 0 south latitude, the average salinity of the water is 32% 0.
Also in this ocean there is a huge speed of movement of the trade winds and monsoons. Therefore, large surface currents are formed here, changing every season. The largest of them is the Somali current, which flows from north to south in winter, and with the onset of summer it changes direction.
Relief of the bottom of the Indian Ocean
The bottom relief is varied and complex. A divergent system of mid-ocean ridges stands out in the southeast and northwest. They are characterized by the presence of rifts, transverse faults, seismicity and underwater volcanism. Between the ridges there are numerous deep-sea basins. The shelf at the bottom of the ocean is mostly small, but it is expanding off the coast of Asia.
Natural resources of the Indian Ocean
There are many minerals in the Indian Ocean, emeralds, diamonds, pearls and others. precious stones. The Persian Gulf is home to the largest oil field ever developed by man.
Climate of the Indian Ocean
Since the Indian Ocean borders the continents, then climatic conditions are determined by some measure by the surrounding land. It has the unspoken status of "monsoon". The fact is that a sharp contrast over the sea and land is strong winds, monsoons.
In summer, in the north of the ocean, the land heats up strongly and a low pressure area arises, which causes heavy precipitation over the ocean and the mainland. This phenomenon was called the “southwest equatorial monsoon.” In winter, the weather is harsher: destructive hurricanes are observed in the ocean, floods on land. Asia is dominated by the region high pressure and trade winds.
Organic world of the Indian Ocean
The animal world is quite diverse and rich, especially in coastal areas and the tropical part. Coral reefs stretch along the entire Indian Ocean and continue into the Pacific. There are many thickets of mangroves in coastal waters. In the tropical region, there is a large amount of plankton, which, in turn, serves as food for larger fish (sharks, tuna). Sea turtles and snakes swim in the waters.
Anchovy, sardinella, mackerel, dolphin, flying fish, tuna, shark swim in the northern part. In the south there are white-blooded and notothenic fish, cetaceans and pinnipeds. In the thickets there is a large accumulation of shrimps, lobsters, krill.
It is interesting that against the background of such a vast diversity of the animal world, in the south of the Indian Ocean, an oceanic desert stands out, where life forms are minimal.
Indian Ocean interesting facts
- The surface of the Indian Ocean is covered with luminous circles from time to time. They disappear, then reappear. Scientists have not yet reached a consensus on the nature of these circles, but suggest that they appear due to the huge concentration of plankton floating on the surface of the water.
- In the ocean is the most salty on the planet (after the Dead) - this is the Red Sea. Not a single river flows into it, so it is not only salty, but also transparent.
- The most dangerous poisoner lives in the Indian Ocean - the blue-ringed octopus. Its dimensions are no larger than a golf ball. However, after being hit by it, a person begins to experience suffocation after 5 minutes and dies after 2 hours.
- This is the warmest ocean on the planet.
- Near the island of Mauritius, you can observe an interesting natural phenomenon - an underwater waterfall. From the outside it looks real. Such an illusion arises due to the runoff of sand in the water and the deposition of silt.
We hope that the message about the Indian Ocean helped you prepare for the lesson. And you can add a story about the Indian Ocean through the comment form below.
It has the fewest seas. It has a peculiar bottom topography, and in the northern part - a special system of winds and sea currents.
Mostly located in the Southern Hemisphere between, and. Its coastline is slightly indented, with the exception of the northern and northeastern parts, where almost all the seas and large bays are located.
Unlike other oceans, the mid-ocean ridges of the Indian Ocean consist of three branches radiating from its central part. The ridges are dissected by deep and narrow longitudinal depressions - grabens. One of these huge grabens is the Red Sea depression, which is a continuation of the faults in the axial part of the Arabian-Indian mid-ocean ridge.
Mid-ocean ridges divide the bed into 3 large sections that are part of three different ones. The transition from the ocean floor to the continents is gradual everywhere, only in the northeastern part of the ocean is the arc of the Sunda Islands, under which the Indo-Australian lithospheric plate. Therefore, a deep-sea trench about 4000 km long stretches along these islands. There are more than a hundred active volcanoes, among which the famous one is Krakatau, earthquakes often occur.
At the surface of the Indian Ocean depends on the geographical latitude. The northern part of the Indian Ocean is much warmer than the southern part.
Monsoons form in the northern part of the Indian Ocean (to the north of 10 S). In summer, the southwest summer monsoon blows here, carrying moist equatorial air from the sea to land, in winter - the northeast winter monsoon, carrying dry tropical air from the continent.
The system of surface currents in the southern half of the Indian Ocean is similar to the system of currents in the corresponding latitudes of the Pacific and Atlantic oceans. However, north of 10°N. a special regime of water movement arises: monsoonal seasonal currents appear, changing direction to the opposite twice a year.
The organic world of the Indian Ocean has much in common with the organic world of the Pacific and Atlantic Oceans in the corresponding latitudes. In the shallow waters of the hot zones, coral polyps are common, creating numerous reef structures, including islands. Among the fish, the most numerous are anchovies, tuna, flying fish, sailfish, and sharks. The tropical coasts of the mainland are often occupied by mangroves. They are characterized by peculiar plants with terrestrial respiratory roots and special animal communities (oysters, crabs, shrimps, mudskipper fish). The bulk of the ocean animals are invertebrate planktonic organisms. In tropical coastal areas, sea turtles, poisonous sea snakes, endangered mammals - dugongs are common. Whales, sperm whales, dolphins, and seals live in the cold waters of the southern part of the ocean. Among the birds, the most interesting are the penguins that inhabit the coasts of South Africa, Antarctica and the islands of the temperate zone of the ocean.
Natural resources and economic development
The Indian Ocean has great biological wealth, but fishing is mostly limited coastal areas, where, in addition to fish, lobsters, shrimps, mollusks are caught. In the open waters of hot zones, tuna is fished, and in cold waters - whales and krill.
Of the most important oil fields and natural gas. The Persian Gulf with the land adjacent to it stands out especially, where 1/3 of the oil of the foreign world is extracted.
In the last decades of the coast warm seas and the islands of the northern part of the ocean are becoming more and more attractive for people to relax, and the tourism business is booming here. Through the Indian Ocean, the volume of traffic is much less than through the Atlantic and Pacific Oceans. However, it plays an important role in the development of the countries of South and Southeast Asia.
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 the scale and quantity of water reserves, the Indian Ocean is comfortably located in third place, behind 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 indicate the exact geographical position of the 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 the Eastern Hemisphere. On the southwest side, it borders the Atlantic Ocean. In order to see this place on the map, you need to find 20 ° along the meridian in. e. The border with the Pacific Ocean is 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 largest continent - Eurasia.
The structure of the coastline has a weak dismemberment. 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. Most high temperatures 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 located in a hot climate zone, due 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. During the summer period, areas with low pressure are established over land, and areas with high pressure over the ocean. 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 a very important issue that deserves special attention. Due to its large size, this area has many features. Along the coastline there are a huge number of 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.
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