Large seas included in the Indian Ocean basin. Largest seas

Ocean area – 76.2 million sq. km;
Maximum depth – Sunda Trench, 7729 m;
Number of seas – 11;
The most big seas– Arabian Sea, Red Sea;
The largest bay is the Bay of Bengal;
The most large islands– Madagascar island, Sri Lanka;
The strongest currents:
- warm - South Passatnoe, Monsoon;
- cold - Western Winds, Somali.

The Indian Ocean ranks third in size. Most of it is in Southern Hemisphere. In the north it washes the shores of Eurasia, in the west – Africa, in the south – Antarctica, and in the east – Australia. Coastline The Indian Ocean is slightly indented. On the northern side, the Indian Ocean is seemingly shrouded in land, making it the only ocean that is not connected to the Arctic Ocean.
The Indian Ocean was formed as a result of the split ancient continent Gondwana in pieces. It lies on the boundary of three lithospheric plates - the Indo-Australian, African and Antarctic. The mid-ocean ridges of the Arabian-Indian, West Indian and Australian-Antarctic are the boundaries between these plates. Underwater ridges and elevations divide the ocean floor into separate basins. The ocean shelf zone is very narrow. Most of the ocean lies within the boundaries of the bed and has considerable depth.

From the north, the Indian Ocean is reliably protected by mountains from the penetration of cold air masses. Therefore, the temperature of surface waters in the northern part of the ocean reaches +29 ˚С, and in the summer in the Persian Gulf it rises to +30...+35 ˚С.
An important feature of the Indian Ocean is monsoon winds and the monsoon current they created, which changes its direction seasonally. Hurricanes are frequent, especially around the island of Madagascar.
The coldest areas of the ocean are in the south, where the influence of Antarctica is felt. In this part Pacific Ocean there are icebergs.
The salinity of surface waters is higher than in the World Ocean. The salinity record was recorded in the Red Sea – 41%.
The organic world of the Indian Ocean is diverse. Tropical water masses are rich in plankton. The most common fish include: sardinella, mackerel, tuna, mackerel, flounder, flying fish and numerous sharks.
Shelf areas and coral reefs are especially rich in life. IN warm waters There are giants in the Pacific Ocean sea ​​turtles, sea snakes, a lot of squid, cuttlefish, starfish. Whales and seals are found closer to Antarctica. Pearls are mined in the Persian Gulf near the island of Sri Lanka.
Important shipping routes pass through the Indian Ocean, mostly in its northern part. The Suez Canal, dug at the end of the 19th century, connects the Indian Ocean with the Mediterranean Sea.
The first information about the Indian Ocean was collected 3 thousand years BC by Indian, Egyptian and Phoenician sailors. The first sailing routes in the Indian Ocean were drawn up by the Arabs.
Vasco da Gama, after the discovery of India in 1499, Europeans began to explore the Indian Ocean. During an expedition, the English navigator James Cook made the first measurements of the depth of the ocean.
A comprehensive study of the nature of the Indian Ocean begins at the end of the nineteenth century.
Nowadays, the warm waters and picturesque coral islands of the Indian Ocean, which attract the attention of tourists from around the world, are carefully studied by numerous scientific expeditions from all over the world.

The Indian Ocean is the third largest ocean. Geologically it is largely a relatively young ocean, although it should be noted, as with other oceans, that many aspects of its earliest geological history and origins are not yet understood. Western border south of Africa: along the meridian of Cape Agulhas (20° E) to Antarctica (Donning Maud Land). Eastern border south of Australia: along the western border of Bass Strait from Cape Otway to King Island, then to Cape Grim (North-West Tasmania) and from the south-eastern tip of the island of Tasmania along 147° E. to Antarctica (Fisher Bay, George V Coast). In a relationship eastern border north of Australia there have been many discussions caused by the fact that some scientists attribute the Arafura Sea, and some even the Timor Sea

sea ​​to the Pacific Ocean, although this is not entirely logical, since the Timor Sea, by the nature of the hydrological regime, is inextricably linked with the Indian Ocean, and the Sahul shelf, geologically, is clearly part of the North-West Australian Shield, connecting the area of ​​​​the once existing Gondwana with the Indian ocean Most geologists draw this boundary along the narrowest (western) part of the Torres Strait; according to the definition of the International Hydrographic Office, the western border of the strait runs from Cape York (11° 05" S, 142° 03" E) to the mouth of the Bensbeck River ( New Guinea) (141° 01" E), which also coincides with the eastern border of the Arafura Sea.

The northeastern border of the Indian Ocean runs (from island to island) through the Lesser Sunda Islands to the islands of Java, Sumatra and then to the islands of Singapore. About the marginal seas of the Indian Ocean, located along its northern border. The area south of the Cape Agulhas-Cape Louin line (Western Australia) is sometimes considered the southern sector of the Indian Ocean.

Indian Ocean area within the boundaries excluding the Arafura Sea 74,917 thousand km2, with the Arafura Sea 75,940 thousand km. Average depth 3897 m; maximum recorded depth 7437 m3. Volume of Indian Ocean waters 291,945 thousand km3.

Bottom relief

Bathymetrically, the Indian Ocean can be divided into five morphological units.

Mainland margins

The Indian Ocean shelves are on average slightly narrower than the Atlantic Ocean shelves; their width ranges from a few hundred meters around some oceanic islands to 200 km or more in the Bombay area. The bend that forms the outer edge of the shelves of Africa, Asia and Australia has an average depth of 140 m. The boundary of the continental platform is formed by the continental slope, steep marginal scarps and the slopes of the trenches.

The continental slope is cut through by numerous underwater canyons. Particularly long underwater canyons lie along the continuation of the mouths of the Ganges and Indus rivers. The continental foot has slopes from 1:40 at the border with the continental slope to 1:1000 at the border with the abyssal plains. The relief of the continental foot is characterized by isolated seamounts, hills and canyons. Submarine canyons at the foot of the continental slope are usually narrow in diameter and difficult to detect, so few of them have been well surveyed. The areas around the mouths of the Ganges and Indus rivers have large accumulations of sediment known as archipelagic fans.

The Java Trench stretches along the Indonesian arc from Burma to Australia. On the Indian Ocean side it is bordered by a gently sloping outer ridge.

ocean bed

The most characteristic elements of the relief of the ocean floor are the abyssal plains. The slopes here range from 1: 1000 to 1: 7000. With the exception of isolated peaks of buried hills and mid-ocean canyons, the height of the relief of the ocean floor does not exceed 1-2 m. The abyssal plains of the northern and southern parts of the Indian Ocean are very clearly expressed, however, near Australia they are less pronounced. The seaward margins of abyssal plains are usually characterized by abyssal hills; Some areas are characterized by low, linearly elongated ridges.

Microcontinents

The most characteristic feature of the bottom topography of the Indian Ocean are microcontinents elongated from north to south. In the northern part of the Indian Ocean, in the direction from west to east, the following aseismic microcontinents can be identified: Mozambique Ridge, Madagascar Ridge, Mascarene Plateau, Chagoss-Laccadive Plateau, Ninetiest Ridge. In the southern part of the Indian Ocean, the Kerguelen Plateau and the asymmetrical Broken Ridge, which extends from east to west, have a noticeable meridional linearity. Morphologically, microcontinents are easily distinguished from a mid-ocean ridge; they usually represent higher areas of massifs with more leveled relief.

A clearly defined microcontinent is the island of Madagascar. The presence of granites in the Seychelles also suggests that at least the northern part of the Mascarene Plateau is of continental origin. The Chagos Islands are coral islands rising above the surface of the Indian Ocean in the area of ​​the vast, gently curved Chagos-Laccadive Plateau. The Ninetiest Ridge is perhaps the longest and most linear ridge discovered in the World Ocean during the International Indian Ocean Expedition. This ridge was traced from 10° N. w. up to 32° S

In addition to the microcontinents mentioned above, there is a distinct Diamantina fault zone in the Indian Ocean for 1,500 miles west of the southwestern tip of Australia. Broken Ridge, which forms the northern boundary of this fault zone, at 30° S. w. connects to the Ninetyist Ridge, which runs at right angles to the Diamantina fault zone in a north-south direction.

Mid-ocean ridge

The most pronounced feature of the Indian Ocean floor is the Central Indian Ridge, part of the global mid-ocean ridge, which in the central Indian Ocean is shaped like an inverted V. Along the axis of this mid-ocean ridge runs a seismically active depression, or rift. The entire ridge has a generally mountainous topography with trends parallel to the axis of the ridge.

Fracture zones

The Indian Ocean is dissected by several clearly defined fault zones that displace the axis of the mid-ocean ridge. To the east of the Arabian Peninsula and the Gulf of Aden is the Owen Fracture Zone, which shifts the axis of the mid-ocean ridge approximately 200 miles to the right. The recent formation of this displacement is indicated by the Whatli Trench, a well-defined depression with depths more than 1000 m greater than the depths of the Indian Abyssal Plain.

Several small right-lateral strike-slip faults displace the axis of the Carlsberg Ridge. In the Gulf of Aden, the axis of the mid-ocean ridge is displaced by several sinistral strike-slip faults running almost parallel to the Owen Fracture Zone. In the southwestern Indian Ocean, the axis of the mid-ocean ridge is offset by a series of left-lateral fault zones that have approximately the same orientation as the Owen Fracture Zone. The Malagasy Fracture Zone, which lies east of the Madagascar Ridge, is likely a southern extension of the fault zone Owen. In the area of ​​the islands of Saint-Paul and Amsterdam, the axis of the mid-ocean ridge is displaced by the Amsterdam Fracture Zone. These zones run parallel to the Nintyist Ridge and have approximately the same meridional orientation as the fault zones in the western Indian Ocean. Although the Indian Ocean is most characterized by meridional strikes, the Diamantina and Rodriguez fault zones extend approximately from east to west.

The highly dissected tectonic relief of the mid-ocean ridge generally presents a noticeable contrast with the very leveled relief of the continental foot and the almost completely smoothed relief of the abyssal plains. In the Indian Ocean, there are areas of smooth-wavy or wavy relief, apparently due to a thick cover of pelagic sediments. The slopes of the mid-ocean ridge south of the polar front are flatter than those north of the polar front. This may be a consequence of higher rates of pelagic sediment deposition due to increased organic productivity in the Southern Ocean.

The Crozet Plateau has an extremely smooth topography. In this region, the narrow zone of the mid-ocean ridge typically has a highly dissected topography, while the ocean floor in this area is extremely smooth.

Indian Ocean climate

Air temperature. In January, the thermal equator for the Indian Ocean is slightly shifted south of the geographic one, in the area between 10 s. w. and 20 U. w. air temperature above 27° C. In the northern hemisphere, the 20° C isotherm, which separates the tropical zone from the temperate zone, runs from the south of the Arabian Peninsula and the Gulf of Suez through the Persian Gulf to the northern part of the Bay of Bengal almost parallel to the Tropic of Cancer. In the southern hemisphere, the isotherm is 10 ° C, which separates temperate zone from the subpolar, runs almost along the parallel of 45° S. In the middle latitudes (southern hemisphere (between 10 and 30° S), isotherms of 27-21° C are directed from WSW to ENE, from South Africa across the Indian Ocean to Western Australia, indicating that the temperature of the western sector in the same latitudes is 1-3° C higher than the temperature of the eastern sector. Off the western coast of Australia, the isotherms of 27–21°C drop to the south due to the influence of the highly heated continent.

In May, the highest temperatures (above 30°C) are observed in the interior of the southern Arabian Peninsula, Northeast Africa, Burma and India. In India it reaches more than 35° C. The thermal equator for the Indian Ocean lies about 10° N. w. Isotherms from 20 to 10°C occur in the southern hemisphere between 30 and 45°S. w. from ESE to WNW, indicating that the western sector is warmer than the eastern one. In July the zone is at its maximum high temperatures on land it moves north of the Tropic of Cancer.

Temperatures over the Arabian Sea and the Bay of Bengal have been decreasing slightly since May, and in addition, the air temperature in the Arabian Sea region is lower than over the Bay of Bengal. Near Somalia, the air temperature due to the rise of cold deep waters drops below 25 ° C. The lowest temperatures are observed in August. In the southern hemisphere, the area west of South Africa is slightly warmer than the central part at the same latitudes. Temperatures off the west coast of Australia are also much higher than inland.

In November, the thermal equator with a small zone of temperatures above 27.5° C almost coincides with the geographic equator. In addition, over the Indian Ocean region north of 20° S. w. the temperature is almost uniform (25-27 C) except for a small area over the central Indian Ocean.

Annual air temperature amplitudes for the central part, between 10° N. w. and 12° S. latitude, less than 2.5 C, and for the area between 4 ° N. w. and 7° S. w. - less than 1 C. In the coastal areas of the Bay of Bengal and the Arabian Sea, as well as in the area between 10 and 40 ° S. w. west of 100° W. d. annual amplitude exceeds 5° C.

Pressure field and surface winds. In January, the meteorological equator (minimum Atmosphere pressure 1009-1012 mbar, calm and variable winds), like the thermal one, is located about 10° south. w. it separates the northern and southern hemispheres, which differ in meteorological conditions.

The predominant wind north of the meteorological equator is the northeast trade wind, or more precisely the northeast monsoon, which changes direction to north at the equator and northwest (northwest monsoon) and the southern hemisphere. South of the meteorological equator, due to the heating of continents in the summer of the southern hemisphere, minimum pressure (less than 1009 mbar) is observed over Australia, Africa and the island of Madagascar. The high pressure area of ​​southern subtropical latitudes is located along 35°S. the maximum pressure (above 1020 mbar) is observed over the central part of the Indian Ocean (near the islands of Saint-Paul and Amsterdam). The northern bulge of the 1014 mbar isobar in the central Indian Ocean is caused by the effect of more low temperatures air and surface waters, in contrast to the South Pacific, where a similar bulge is observed in the eastern sector of South America. South of the high pressure area there is a gradual decrease in pressure towards a subpolar depression near 64.5°S. sh., where the pressure is below 990 mbar. This pressure system creates two types of wind systems south of the meteorological equator. In the northern part, the southeast trade winds cover the entire Indian Ocean, with the exception of areas near Australia, where they change direction to the south or southwest. South of the trade wind region (between 50 and 40° S) westerly winds occur from the Cape of Good Hope to Cape Horn, in an area called the "roaring forties". The significant difference between westerly winds and trade winds is not only that the former have higher speeds, but also that the daily variations in direction and speed for the former are also much greater than for the latter. In July, for a wind field from the north of 10° S. w. The opposite picture to January is observed. An equatorial depression with pressure values ​​below 1005 mbar is located over the eastern part of the Asian continent.

South of this depression the pressure gradually increases from the 20s. w. to 30° south sh., i.e. to the area of ​​the southern borders of the “horse” latitudes. The southern trade winds cross the equator and become the southwest monsoons in the northern hemisphere, very intense, characterized by strong storms off the coast of Somalia in the Arabian Sea.

This area is good example a complete shift of winds with an annual cycle in the northern trade wind zone, which is a consequence of the strong heating and cooling effect of the Asian continent. In the middle and high latitudes of the southern hemisphere, the moderating effect of the Indian Ocean reduces the differences in pressure and wind fields in June and January.

However, at high latitudes, westerly winds increase significantly, and fluctuations in their direction and speed also increase. The frequency distribution of storm winds (more than 7 points) showed that in winter northern hemisphere over most of the Indian Ocean north of 15°S. w. storm winds are virtually not observed (their frequency is less than 1%). In the area of ​​10° south. latitude, 85-95° east. (northwest of Australia) from November to April, tropical cyclones sometimes form, moving to the southeast and southwest. South of 40°S w. The frequency of storm winds is more than 10% even in the summer of the southern hemisphere. In the northern hemisphere summer, from June to August, the southwest monsoons in the western Arabian Sea (off the coast of Somalia) are always so strong that approximately 10-20% of the winds are force 7. During this season, calm zones (with a frequency of storm winds of less than 1%) shift to the area between 1° south. w. and 7° N. w. and west of 78° E. d. In the area of ​​35-40° S. w. The frequency of storm winds increases by 15-20% compared to the winter season.
Cloud cover and precipitation. In the northern hemisphere, cloud cover exhibits significant seasonal variations. During the northeast monsoon period (December-March), cloudiness over the Arabian Sea and Bay of Bengal is less than 2 points. However, in summer the southwest monsoons bring rainy weather to the region of the Malay Archipelago and Burma, with average cloudiness already 6-7 points. The area south of the equator, the southeastern monsoon zone, is characterized by high cloudiness throughout the year - 5-6 points in the summer of the northern hemisphere and 6-7 points in the winter. Even in the southeast monsoon zone there is a relatively large cloud cover and there are extremely rare areas of cloudless sky characteristic of the southeast Pacific monsoon zone. Cloudiness in areas west of Australia exceeds 6 points. However, near the coast of Western Australia it is quite cloudless.

In summer, sea fog (20-40%) and very poor visibility are often observed off the coast of Somalia and the southern part of the Arabian Peninsula. The water temperature here is 1-2°C lower than the air temperature, which causes condensation, enhanced by dust brought from deserts on the continents. The area south of 40° S. w. also characterized by frequent sea fog throughout the year.

Total annual precipitation for the Indian Ocean is high - more than 3000 mm at the equator and more than 1000 mm in the western zone of the southern hemisphere. Between 35 and 20° S. w. in the trade wind zone, precipitation is relatively rare; The area off the western coast of Australia is especially dry, with precipitation less than 500 mm. The northern boundary of this dry zone is parallels 12-15° S, that is, it does not reach the equator, as in the South Pacific Ocean. The northwest monsoon zone is generally the boundary region between the northern and southern wind systems. To the north of this area (between the equator and 10° S) is the equatorial rainy zone, which stretches from the Java Sea to Seychelles. In addition, very high rainfall is observed in the eastern part of the Bay of Bengal, especially in the Malay Archipelago region. The western Arabian Sea is very dry, and the rainfall in the Gulf of Aden and the Red Sea is less than 100 mm. Maximum precipitation in rainy zones is in December-February between 10 and 25° S. w. and in March-April between 5 s. w. and 10th south. w. in the western part of the Indian Ocean. Maximum values ​​in the summer of the northern hemisphere are observed in the Bay of Bengal. The highest heavy rains almost throughout the year are observed west of the island of Sumatra.

Temperature, salinity and density of surface waters

In February, the northern Indian Ocean experiences typical winter conditions. In the interior regions of the Persian Gulf and the Red Sea, the surface water temperature is 15 and 17.5 ° C, respectively, while in the Gulf of Aden it reaches 25 ° C. Isotherms of 23-25 ​​° C go from southwest to northeast, and therefore , the surface waters of the western part of the Indian Ocean are warmer than the surface waters of the eastern part for the same latitudes (the same for air temperature).

This difference is caused by water circulation. It is observed in all seasons of the year. In the southern hemisphere, where it is summer at this time, the zone of high surface temperatures (above 28 ° C) runs in the direction ENE from the eastern coast of Africa to the area west of the island of Sumatra and then south of Java and north of Australia, where the water temperature sometimes exceeds 29° C. Isotherms 25-27° C between 15 and 30 degrees south. w. directed from WSW to ENE, from the coast of Africa to approximately 90-100° E. etc., then they turn to the southwest, just like in the western part of the Bay of Bengal, in contrast to the South Pacific, where these isotherms are directed off the coast of South America to the ENE. Between 40 and 50° S. w. there is a transition zone between water masses of mid-latitudes and polar waters, which is characterized by thickening of isotherms; temperature difference is about 12° C.

In May, the surface waters of the northern Indian Ocean heat up to their maximum and have temperatures generally above 29 ° C. At this time, the northeast monsoons give way to the southwest, although rains and sea level rise are not yet observed at this time. In August, only in the Red Sea and the Persian Gulf the water temperature reaches a maximum (above 30 ° C), however, the surface waters of most of the northern sector of the Indian Ocean including the Gulf of Aden, the Arabian Sea and most of the Bay of Bengal, with the exception of its western regions, have lower temperatures than in May. The zone of low temperatures of the surface layer (below 25°C) stretches from the coast of Somalia to the southeastern coast of the Arabian Peninsula. The decrease in temperature is caused by the intense rise of cold deep waters due to the southwest monsoons. In addition, in August there are three characteristic features of temperature distribution south of 30°S. latitude: isotherms of 20-25° C in the eastern and central parts of the Indian Ocean are directed from WSW to ENE, and thickening of isotherms is noted between 40 and 48° S. sh., and isotherms west of Australia are directed south. In November, surface water temperatures are generally close to the annual average. The low temperature zone (below 25°C) between the Arabian Peninsula and Somalia and the high temperature zone in the western Bay of Bengal are almost disappearing. In a huge area of ​​water north of 10° south. w. surface layer temperatures range between 27 and 27.7° C.

The salinity of surface waters of the southern Indian Ocean has the same distribution features that are characteristic of the South Pacific Ocean. To the west of Australia, the maximum salinity value is observed (above 36.0 ppm). Equatorial zone low salinity, corresponding to the transition zone between the southeast trade winds and monsoons, extends to 10° S. sh., but clearly expressed only in the eastern part of the Indian Ocean.
The minimum salinity values ​​in this zone are observed south of the islands of Sumatra and Java. The salinity of surface waters in the northern Indian Ocean varies not only regionally but also seasonally. In the summer of the northern hemisphere, the salinity of surface waters has the following characteristic features: it is extremely low in the Bay of Bengal, quite high in the Arabian Sea and very high (above 40 ppm) in the Persian Gulf and the Red Sea.

The density of surface waters in the southern part of the Indian Ocean in the summer of the southern hemisphere decreases uniformly northward from approximately 27.0 in the region of 53-54° S. w. to 23.0 at 17° S. sh.; in this case, the isopycnals run almost parallel to the isotherms. Between 20° S. w. and 0° there is a huge zone of low-density waters (below 23.0); near the islands of Sumatra and Java there is a zone with a density below 21.5, corresponding to the zone of minimum salinity in this area. In the northern Indian Ocean, density changes are influenced by salinity. In summer, the density decreases from 22.0 in the southern part of the Bay of Bengal to 19.0 in its northwestern part, while for most of the Arabian Sea it is above 24.0, and near the Suez Canal and in the Persian Gulf it reaches 28.0 and respectively. 25.0. In addition, seasonal changes in surface water density are mainly caused by changes in temperature. For example, the northern part of the Indian Ocean is characterized by an increase in density by 1.0–2.0 from summer to winter.

Indian Ocean Currents

Currents in the northern Indian Ocean, which are strongly influenced by the monsoon and vary seasonally, are called the southwest and northeast monsoon drifts for summer and winter respectively. The Southern Trade Wind Current and the Western Wind Current pass through the southern part of the Indian Ocean. In addition to these currents, closely related to wind systems, there are currents of a local nature, caused mainly by the density structure of the Indian Ocean, such as the Mozambique Current, Cape Agulhas Current, Inter-trade (equatorial) countercurrent, Somali Current and West Australian Current.

The southern Indian Ocean experiences a large anticyclonic circulation similar to that in the southern Pacific and Atlantic Oceans, but is subject to greater annual variations. Its extreme southern part is the Western Winds Current (between 38 and 50° S), 200-240 miles wide, increasing in an easterly direction. This current borders the subtropical and Antarctic convergence zones. The speed of the current depends on the strength of the wind and varies seasonally and regionally. Maximum speed(20-30 miles/day) is observed near Kerguelen Island. In the summer of the southern hemisphere, this current, when approaching Australia, turns north and connects with the current coming from the Pacific Ocean south of Australia.

In winter, the wind drift joins the southward current along the western coasts of Australia and continues into the Pacific Ocean along the southern coasts of Australia. The eastern part of the aiticyclonic circulation in the southern hemisphere is the Western Australian Current, which has a steady northerly direction only in the summer of the southern hemisphere and reaches 10-15 miles/day north of 30° S. w. This current becomes weak in winter and changes direction to the south.

The northern part of the anticyclonic gyre is the Southern Trade Wind Current, which originates in the area where the Western Australian Current exits the Tropic of Capricorn under the influence of southeastern trade winds. The maximum speed of the current (more than 1 knot) is observed in its eastern part in the winter of the southern hemisphere, when the westerly flow from the Pacific Ocean increases north of Australia. In the summer of the southern hemisphere, when this flow becomes easterly, the northern boundary of the South Trade Wind Current is between 100 and 80° E. located about 9° south. latitude, shifting slightly to the southeast from 80° east. d.; Its southern border at this time passes about 22° south. w. in the eastern sector. In the winter of the southern hemisphere, the northern boundary of this current shifts northward by 5-6°, following the northern shift of the southeast trade wind. Before the island of Madagascar, the current divides into several branches.

One of them goes north around the island of Madagascar at a speed of up to 50-60 miles/day and then turns west. It splits again into two branches at Cape Delgado. One branch turns north (East African Coastal Current), the other turns south, following through the Mozambique Channel (Mozambique Current). The speed of this current varies from almost zero to 3-4 knots during the northeast monsoon.

The Cape Agulhas Current is formed from the continuation of the Mozambique Current and the southern branch of the South Trade Wind Current south of the island of Mauritius. This current, narrow and clearly defined, extends from the coast for less than 100 km. As is known, a southward flow in the Southern Hemisphere is characterized by a tilt of the water surface to the left. At a distance of 110 km from Port Elizabeth, the slope of the level towards the ocean increases by approximately 29 cm. Between Durban and 25° E. The speed of this current at the edge of the Agulhas Bank reaches 3-4.5 knots. South of Africa, the main part of the current turns sharply to the south and then to the east and thus unites with the current of the Western Winds. However, a small one continues to move into the Atlantic Ocean. Due to the change in directions and razor-sharp currents, numerous eddies and gyres develop along the coast of South Africa, the position of which changes throughout the year.

North of 10° S. w. There is strong variability in Indian Ocean surface currents from winter to summer. During the northeast monsoon, from November to March, the Northern Trade Wind Current (drift of the northeast monsoon) develops. The southern boundary of this current varies from 3-4° N. w. in November up to 2-3° S. w. in February. In March, the current turns north again and disappears with the advent of the southwest monsoon drift. With the onset of the northeastern monsoon (from November), the Intertrade Countercurrent begins to develop. It is formed under the joint influence of the current running southwest of the coast of Somalia and the East African coastal current, going north from the cape. Delgado. The countercurrent is narrow and reaches almost to the island of Sumatra. Northern border in November it passes north of the equator, and in February it shifts to 2-3° S. Later, the current rises again to the north and then disappears. The southern boundary of the current lies between 7 and 8° S. w. Current speed between 60 and 70° E. d. reaches 40 miles/day, but further east it decreases.

During the southwest monsoon, from April to October, the North Trade Wind Current (the drift of the northeast monsoon disappears and is replaced by the drift of the southwest monsoon going east south of India. South of the island of Sri Lanka its speed is 1-2 knots, and sometimes reaches 3 knots. The branches of this current create a clockwise circulation in the Arabian Sea, following the contours of the coastline. The speed of the southeasterly flow off the western coast of India reaches 10-42 miles/day. During this season, the Somali Current along the coast of Somalia in the area of ​​10° S. w. directed north, and the waters of the South Trade Wind Current cross the equator. Off the coast of Somalia, there is an intense rise in waters, causing cooling of surface waters over a large area.

Subsurface currents in the Indian Ocean north of 10°S. w. were measured at horizons of 15, 50, 100, 200, 300, 500 and 700 m during the 31st voyage of the Vityaz (January-April 1960), at approximately 140 deep-sea stations.

As established, at a depth of 15 m, the distribution of currents turned out to be almost similar to the surface one in the winter of the northern hemisphere, with the exception that, according to observational data, the Intertrade Wind Countercurrent originates at 60° E. and covers the area between 0 and 3° S. those. its width is much smaller than on the surface. On the horizon 200 m of current south of 5° N. w. have a direction reverse currents on a horizon of 15 m: they are directed to the east under the Northern and Southern Trade Wind Currents and to the west under the Interpassat Countercurrent east of 70° east. d. At a depth of 500 m, the current is between 5° N. w. and 10° S. w. in general they have east direction and form a small cyclonic gyre with a center at 5°S. latitude, 60° east. d. In addition, direct current measurements and dynamic calculation data for the period November-December 1960, obtained during the 33rd voyage of the Vityaz, indicate that the observed current system does not yet correspond to the current system characteristic of the winter monsoon , despite the fact that northwest winds are already beginning to prevail here. At a depth of 1500 m south of 18° S. w. An easterly current was detected at a speed of 2.5-45 cm/s. About 80° E. This current combines with the southern flow, which has a speed of 4.5-5.5 cm/s and its speed is rapidly increasing. About 95°E. This current sharply turns north and then west, forming an anticyclonic gyre, the northern and southern parts of which have speeds of 15-18 and 54 cm/s, respectively.

About 20-25° S. latitude, 70-80° east. The southern branch of this current has a speed of less than 3.5 cm/s. At a horizon of 2000 m between 15 and 23° S. w. the same current has an eastern direction and a speed of less than 4 cm/s. About 68°E. d. a branch departs from it, going north at a speed of 5 cm/s. Anticyclonic gyre between 80 and 100° E. at a horizon of 1500 m covers a large area between 70 and 100° east. e. A current coming south from the Bay of Bengal meets another current coming from the east at the equator and turns north and then northwest to the Red Sea.

On the horizon 3000 m between 20 and 23° S. w. the current is directed to the east with speeds in some places up to 9 cm/s. Cyclonic gyre at 25-35° S. latitude, 58-75° E. d. becomes clearly expressed here at speeds of up to 5 cm/s. Anticyclic cycle between 80 and 100 centuries. observed at a horizon of 1500 m, here it breaks up into a number of small vortices.

Water masses

The Indian Ocean, in addition to the subantarctic water mass, is characterized by three main water masses: the central water mass of the Indian Ocean (subtropical subsurface), the equatorial water mass of the Indian Ocean, extending to medium depths, and the deep water of the Indian Ocean, below the horizon of 1000 m. There are also intermediate water masses. These are Antarctic intermediate waters, the waters of the Red Sea and others at medium depths.

India, drowning in ocean waves, attracts tourists from all over the world. Goa is especially attractive to vacationers. Tour operators promise a lot of impressions and completely different beaches. To get the most out of swimming, you need to know what Goa is surrounded by. Then the waves and sand will make you come back more than once.

What Goa washes

When wondering what kind of sea awaits on the coast, be prepared to receive different answers.

Most often called the Arabian Sea. However, its currents are an integral part of the ocean in Goa.

Hindustan, on which India is located, gave its name to the third largest water area on Earth. This is why inexperienced travelers get lost and cannot decide whether the Arabian Sea or the Indian Ocean washes the tourist paradise.

Some features of a sea holiday in Goa

The majestic and diverse Indian Ocean occupies a huge space and is the largest attraction of the state.

Here it has its own characteristics:

1. You can swim all year round.

   Indian Ocean on the map

   The sea warms up to 28 degrees, deviations of a couple of degrees do not play a role in the weather. Despite this, you should not swim after sunset at any time of the year; stingrays and sea snakes become more active;

2. You can enjoy the Indian Ocean completely free of charge. The coast is completely free and is under the care of the municipality. No hotel has the right to block access to the beach. The buildings are located no closer than 200 m;
3. The Arabian Sea is excellent for diving, especially in the bays and bays.

   Although the underwater world is significantly inferior to the diversity of other recognized water areas. The Indian Ocean washing the resort creates a lot of waves. The water is often cloudy due to strong currents. Red or Mediterranean Sea much richer in flora and fauna and more transparent;

4. A coastline that is always washed warm current, leaves much to be desired in terms of cleanliness. But this is a characteristic feature of India. The water here is designed not only to wash the shores, but also to wash away garbage from them.

In fact, India attracts tourists with its authentic culture, tropical nature, the opportunity to touch thousands of years of history and original philosophy, especially in Goa.

The sea or the ocean washes the coast - it doesn’t matter at all. The main thing is the sun and nature in the heart of an oriental fairy tale.

Indian Ocean - area and location

INDIAN OCEAN (Geography)

Location: the body of water between Africa, the Southern Ocean, Asia and Australia.
Geographical coordinates: 20° 00′ S

la., 80° 00′ E. d.
Reference map:
Square: total: 68.556 million sq. km; note: includes the Andaman Sea, Arabian Sea, Bay of Bengal, Great Australian Bight, Gulf of Aden, Gulf of Oman, Mozambique Strait, Persian Gulf, Red Sea, Strait of Malacca and other waters.
Comparative area: approximately 5.5 times the size of the USA.
Land borders:
Coastline: 66,526 km.
Maritime claims:
Climate: northeast monsoons (December to April), southwest monsoons (June to October); tropical cyclones occur during May-June and October-November in the northern Indian Ocean and January-February in the southern Indian Ocean.
Relief: the ocean surface is dominated by wide circular, counterclockwise currents in the southern Indian Ocean; the unique reverse direction of surface currents in the northern Indian Ocean; low air pressure over southwest Asia due to warm rising summer air currents results in southwest monsoons and southwest to northeast currents, while high pressure over northern Asia due to cold winter downdrafts air flows lead to the emergence of northeast monsoons and currents directed from northeast to southwest; the ocean floor is dominated by the Central Indian Ridge and is home to the Southwestern Indian Ridge, the Southeastern Indian Ridge and the 90°E Ridge.
Maximum and minimum heights: lowest point: Java Basin -7,258 m; highest point: sea level 0 m.
Natural resources: oil and gas reserves, fish, shrimp, sand and gravel deposits, gold sand deposits, polymetallic ore deposits on the ocean floor.
Land use:
Irrigated lands:
Natural hazards:
Current environmental issues: endangered marine species including dugongs, seals, turtles and whales; oil pollution in the Arabian Sea, Persian Gulf and Red Sea.
International agreements on environmental protection:
Note to the "Geography" section: The areas with the heaviest shipping traffic are the Strait of Bab el Mandeb, the Strait of Hormuz, the Strait of Malacca, the southern entrance to the Suez Canal and Lombok.

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Economic and geographical assessment of the level of economic development of the Indian Ocean

Factors of economic development	Indian Ocean Provinces
Northwestern	grade	North-Eastern	grade	Eastern	grade	Western	grade
Economic-geographical and political situation Mineral resources And largest deposits: - coastal-marine placers - ferromanganese and phosphorite nodules - oil and gas	The water area between the island. Sri Lanka, Maldives and Seychelles, Af. mainland and ber. South-West Asia Somalia, Egypt Oman, Yemen, India Persian Gulf and Red Sea	+ ↕	Bay of Bengal, Andaman Sea	— ↕	Maldives and Chagos Archipelago and Central Indian Ridge to the Indonesian and Australian coasts, coastal areas of Australia	+ ↕	The water area between the Central Basin and the African continent of Mozambique	+ ↕
Chemical resources	Uranus	+ ↕	Uranus	+ ↕		+ ↕		+ ↕
Energetic resources	Oil Gas	+ ↕	Hard coal, oil and brown coal deposits	+ ↕	Oil Gas, coal(coastal Australia)	+ ↕	Oil and gas fields	+ ↕
Biological resources (fish productivity, production volume, leading countries in catches of fish, crustaceans and mollusks, aquaculture)	The fish productivity of the ocean zone is low. In coastal areas of India and Saudi Arabia increases over 100 kg/km2.	+ ↕	An area of ​​intensive marine fishing, fish productivity on the shelf exceeds 200 kg/km2. India is the leader in catches.	+ ↕	The fish productivity of the open part is low (10 kg/km2); on the Sunda Islands shelf it exceeds 200 kg/km2.	+ ↕	The fish productivity of the open part is low (10 kg/km2); on the African coast it exceeds 200 kg/km2.	+ ↕
Maritime transport (the largest ports, port zones and port points, their geographical types, cargo turnover, volume of container transshipment, specialization, transoceanic and interregional sea routes)	The Persian Gulf is a major economic region. Oil production and export of fuel resources. The main ports are Damam, Ras Tanura, Ras Haji, Jeddah and Yanbu. It specializes in the petrochemical industry.	+ ↕	Large mineral resources (coal, metal ore raw materials) have been identified. Largest ports: Calcutta, Madras. The eastern economic region of India is the main coal and metallurgical base.	+ ↕	The province plays a great role in maritime transport on the most important routes. Linking the Gulf and South Asian countries with Japan and East Asia. Heavy-duty lines carry: 300-400 million tons of oil, iron ore 80 million tons, bauxite, aluminum, coal, grain. Largest ports: Port Hedland, Dampier.	+ ↕	Favorable transport position on the route of transportation between the European and American continents. The North-Eastern region produces 955 mining products and over 60% of the manufacturing industry. Main transportation: oil (Persian Gulf), iron ore, agricultural products. products. Largest port: Durban, Richards Bay.	+ ↕
Branches of the coastal economy	Shipbuilding, port activities.	+ ↕	Fishing, Cultivation of rice, sugar cane, rubber.	+ ↕	Fishing, agriculture	+ ↕	Mining industry, industrial production	+ ↕
Provincial assessment		Not all factors with an average value and a neutral influence on economic development are conducive to economic development. Indian Ocean	Factors promoting economic development, with an average value, with a neutral impact on economic development.	Factors promoting economic development, with an average value, with a neutral impact on economic development.
Ocean assessment with comments	The area of ​​the Indian Ocean is 74.17 million. km2. The world's largest oil and gas reserves are located here - estimated at 67 billion tons, of which 45% of marine resources are concentrated in the countries of the Near and Middle East. Mining is also carried out in the northwestern and western coasts of Australia, the Gulf of Cambay. Large deposits of coastal-marine placers are common in Australia, ilmenite-zircon and ilmenite monazite are found in southwestern India and the eastern coast of Sri Lanka; cassiterite - Myanmar, Thailand, Indonesia. Low fish productivity is observed - 35-40 kg/km2. Total catches - 8.7 million tons (India, Indonesia, Myanmar, Thailand, Pakistan). In maritime transport, specialized ports play an important role on the ocean. Low level economic development Most countries in the coastal zone are determined by the low level of port facilities. Concentrates about 1/5 of the world's port cargo turnover and 1/3 of liquid cargo turnover (mainly oil).

Topic No. 8 “Economic and geographical provinces of the Arctic and Southern Oceans”

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Geographical position. The Pacific (or Great) Ocean, in terms of its size and natural features, is a unique natural object on our planet. The ocean is located in all hemispheres of the Earth, between the continents of Eurasia and Australia in the west, North and South America in the east and Antarctica in the south.

The Pacific Ocean occupies more than 1/3 of the planet's surface and almost half of the World Ocean.

It has an oval outline, is somewhat elongated from northwest to southeast and is widest between the tropics. The coastline is relatively straight off the coasts of North and South America and highly dissected off the coast of Eurasia.

Where is the Indian Sea on the map

The Pacific Ocean includes a number of marginal seas Eastern and South-East Asia. There are a large number of archipelagos and individual islands in the ocean (for example, as part of Oceania).

Bottom relief. The Pacific Ocean is the deepest. The topography of its bottom is complex. The shelf (continental shelf) occupies a relatively small area. Off the coast of North and South America its width does not exceed tens of kilometers, and off the coast of Eurasia the shelf measures hundreds of kilometers.

In the marginal parts of the ocean there are deep-sea trenches, and the Pacific Ocean contains the bulk of the deep-sea trenches of the entire World Ocean: 25 out of 35 have a depth of more than 5 km; and all trenches with a depth of over 10 km - there are 4 of these. Large uplifts of the bottom, individual mountains and ridges divide the ocean floor into basins.

In the southeast of the ocean is the East Pacific Rise, which is part of the global system of mid-ocean ridges.

Associated with the system of deep-sea trenches and mountain structures on continents and islands adjacent to the ocean is an almost continuous chain of active volcanoes that form the Pacific “Ring of Fire.” In this zone, land and underwater earthquakes are also frequent, causing giant waves - tsunamis.

The Pacific Ocean stretches from subarctic to subantarctic latitudes, that is, it is located in almost all climatic zones Earth. Its main part is located in the equatorial, subequatorial and tropical zones of both hemispheres.

The air temperature over the waters of these latitudes is from +16 to +24°C all year round. However, in the north of the ocean in winter it drops below 0°C. Along the coasts of Antarctica, this temperature also persists in the summer months.

The circulation of the atmosphere over the ocean is characterized by zonal features: in temperate latitudes Western winds predominate, trade winds dominate in tropical latitudes, and monsoons are pronounced in subequatorial latitudes off the coast of Eurasia. Strong winds of storm force and tropical cyclones - typhoons - are frequent over the Pacific Ocean.

The maximum amount of precipitation falls in the western parts of the equatorial belt (about 3000 mm), the minimum in the eastern regions of the ocean between the equator and the southern tropic (about 100 mm).

Currents. The Pacific Ocean is quite elongated from west to east and therefore latitudinal water flows predominate in it.

Two huge rings of water movement are formed in the ocean: northern and southern. The Northern Ring includes the Northern Trade Wind Current, Kuroshio Current, North Pacific Current and California Current. The southern ring consists of the South Trade Wind, East Australian Current, West Wind Current and Peruvian Current.

Currents have a significant impact on the redistribution of heat in the ocean and on the nature of the adjacent continents - geoglobus.ru. Thus, trade wind currents drive warm waters from the western tropical coasts of continents to the eastern ones, therefore, in low latitudes, the western part of the ocean is significantly warmer than the eastern. In mid-high latitudes, on the contrary, the eastern parts of the ocean are warmer than the western ones.

Properties of water.

All types of surface sediments are formed in the Pacific Ocean water masses, except for the Arctic ones. Because of large area The ocean between the tropics has surface waters that are warmer than those of other oceans. Average annual temperature waters between the tropics are +19°C, in equatorial latitudes - from +25 to +29°C, off the coast of Antarctica - drops to -1°C. Precipitation over the ocean generally dominates evaporation.

The salinity of the surface waters of the Pacific Ocean is slightly lower than in the Atlantic, since the western part of the ocean receives a lot of fresh river water (Amur, Yellow River, Yangtze, Mekong and others). Ice phenomena in the northern part of the ocean and in the subantarctic zone are seasonal. Off the coast of Antarctica, sea ice lasts all year. Antarctic icebergs with surface currents rise to 40° S.

Organic world.

In terms of biomass and number of species, the organic world of the Pacific Ocean is richer than in other oceans. This is explained by its long geological history, huge size, and diversity of environmental conditions.

Organic life is especially rich in equatorial-tropical latitudes, in areas where coral reefs develop. There are many different species of salmon fish in the northern part of the ocean.

Fishing in the Pacific Ocean accounts for more than 45% of global production. The main fishing areas are areas of interaction between warm and cold waters; shelf areas in the western ocean and areas of rising deep waters off the coast of North, and especially South, America.

Natural complexes. The Pacific Ocean has all natural zones except the North Polar. Northern polar belt occupies a small part of the Bering and Okhotsk seas.

In this zone there is intense water circulation, so they are rich in fish. The northern temperate zone occupies vast areas of water. It is characterized by the interaction of warm and cold water masses. This contributes to the development of the organic world. In the west of the belt, a unique aquatic complex of the Sea of ​​Japan is formed, characterized by great species diversity.

The northern subtropical zone in the Pacific Ocean is not as clearly defined as the temperate zone. The western part of the belt is warm, the eastern part is relatively cold.

The waters are slightly mixed, blue, transparent. The number of plankton and fish species is small.

The northern tropical belt is formed under the influence of the powerful North Trade Wind Current. There are many individual islands and archipelagos in this belt.

The productivity of the waters of the belt is low. However, near underwater hills and islands, where the vertical movement of water increases, accumulations of fish and other marine organisms appear.

IN equatorial belt There is a complex interaction of winds and various currents.

At the boundaries of streams, eddies and gyres contribute to the rise of water, and therefore their biological productivity increases. The aquatic complexes off the Sunda Islands and the coast of North-Eastern Australia, as well as coral reef complexes, are richest in life.

In the southern hemisphere, similar natural belts are formed in the Pacific Ocean as in the northern hemisphere, but they differ in some properties of water masses and the composition of organisms.

For example, in the waters of the subantarctic and Antarctic belts inhabited by nototheniids and white-blooded fish. In the south tropical zone between 4 and 23° S. A special aquatic complex is being formed off the coast of South America.

It is characterized by a stable and intense rise of deep waters (upwelling) and the active development of organic life. This is one of the most productive areas of the entire World Ocean.

Economic use.

The Pacific Ocean and its seas wash the coasts of continents on which more than 30 coastal states are located with a total population of about 2 billion people. To the main types natural resources ocean include it biological resources. Ocean waters are characterized high productivity(about 200 kg/km2). In recent years, the Pacific Ocean has ranked first in the world in the production of fish and seafood - geoglobus.ru. Mining began on the ocean shelf: deposits of oil and gas, tin ores and other non-ferrous metals; from sea ​​water receive cooking and potassium salt, magnesium, bromine.

World and regional shipping routes pass through the Pacific Ocean, and a large number of ports are located on the ocean’s shores.

The most important lines run from the banks North America to the Far Eastern shores of Asia. The energy resources of the Pacific waters are large and varied, but are not yet used enough.

Human economic activity has led to severe pollution of some areas of the Pacific Ocean. This was especially evident off the coast of Japan and North America.

The stocks of whales, a number of valuable species of fish and other animals have been depleted. Some of them have lost their former commercial significance.

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 the Southern Hemisphere. Four continents surround it. In the north is the Asian part of Eurasia, in the west is Africa, in the east is Australia 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 on the north from the western coast of the Malacca Peninsula to the northern point of the island of Sumatra and further along the islands of Sumatra, Java, Bali, Sumba, Timor and New Guinea.

There was a lot of controversy among geographers about the eastern border. But now everyone seems to have agreed to count it from Cape York in Australia, through the Torres Strait, New Guinea and further to the 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 boundary runs from Australia to the western coast of the island of Tasmania and further along the meridian to Antarctica.

Semi-enclosed part of the Indian Basin - Arabian Sea on the map

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 (the area of ​​the Atlantic Ocean), its area is 74,917 thousand square kilometers.

Seas of the Indian Ocean

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

Indian Ocean Depth

At the bottom of the Indian Ocean, in its central part, there are several deep-sea basins, separated by underwater ridges and underwater plateaus, and along the Sunda island arc there is deep sea Sunda Trench.

In it, oceanologists 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. The largest islands in the Indian Ocean are 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.

Indian Ocean temperature

The water in the Indian Ocean is warm. In June - August, closer to the equator, its temperature, like 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 ° C.

But from the equator south to Antarctica, the ocean water temperature changes to 26 and even 28 °C. From the north it is limited by the shores of the Eurasian continent. From the south - a conditional line connecting the extremities of South Africa and Australia.

In the west is Africa.

Which ocean is the warmest?

But why is the Indian Ocean considered the youngest? On geographical map You can clearly see how its basin is surrounded by continental land masses. In the not-so-distant geological past of our planet, these areas were most likely united into a single continent, Gondwana, which split apart and its parts spread out into different sides, making room for water.

At the bottom of the Indian Ocean, scientists have discovered several underwater mountain ranges.

Moreover The Central Indian Ridge divides the ocean basin into two regions with absolutely different types earth's crust. Deep cracks are adjacent to seamounts. Such proximity inevitably causes frequent earthquakes in these areas, or rather, seaquakes. As a result, tsunamis are born, which bring untold misfortune to island and coastal mainland residents.

Underwater volcanoes in these troubled areas emit so much material from the depths that from time to time new islands appear in seismic belts.

Many coral reefs and atolls are found in the local warm waters. Navigating 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 have been recorded!.. Giant catastrophic tsunami waves are not such a rare exotic for the inhabitants of the Indian Ocean basin.

The Indian Ocean makes up 20% of the World Ocean by volume. It is bounded by Asia to the north, Africa to the west and Australia to the east.

In the zone 35° S. passes conditional boundary with the Southern Ocean.

Description and characteristics

The waters of the Indian Ocean are famous for their transparency and azure color. The fact is that few freshwater rivers, these “troublemakers,” flow into this ocean. Therefore, by the way, the water here is much saltier than in others. It is in the Indian Ocean that the saltiest sea in the world, the Red Sea, is located.

The ocean is also rich in minerals. The area near Sri Lanka has been famous for its pearls, diamonds and emeralds since ancient times. And the Persian Gulf is rich in oil and gas.
Area: 76.170 thousand sq. km

Volume: 282.650 thousand cubic km

Average depth: 3711 m, greatest depth - Sunda Trench (7729 m).

average temperature: 17°C, but in the north the waters warm up to 28°C.

Currents: two cycles are conventionally distinguished - northern and southern. Both move clockwise and are separated by the Equatorial Countercurrent.

Main currents of the Indian Ocean

Warm:

Northern Passatnoe- originates in Oceania, crosses the ocean from east to west. Beyond the peninsula, Hindustan is divided into two branches. Part flows to the north and gives rise to the Somali Current. And the second part of the flow heads south, where it merges with the equatorial countercurrent.

South Passatnoye- begins at the islands of Oceania and moves from east to west all the way to the island of Madagascar.

Madagascar- branches off from the South Passat and flows parallel to the Mozambique from north to south, but slightly east of the Madagascar coast. Average temperature: 26°C.

Mozambican- another branch of the South Trade Wind Current. It washes the coast of Africa and in the south merges with the Agulhas Current. Average temperature - 25°C, speed - 2.8 km/h.

Agulhas, or Cape Agulhas Current- narrow and fast current, running along the east coast of Africa from north to south.

Cold:

Somali- a current off the coast of the Somali Peninsula, which changes its direction depending on the monsoon season.

Current of the West Winds encircles Earth in southern latitudes. In the Indian Ocean from it is the South Indian Ocean, which, near the coast of Australia, turns into the Western Australian Ocean.

Western Australian- moves from south to north along the western coast of Australia. As you approach the equator, the water temperature rises from 15°C to 26°C. Speed: 0.9-0.7 km/h.

The underwater world of the Indian Ocean

Most of the ocean is located in the subtropical and tropical zones, and is therefore rich and diverse in species.

The tropical coast is represented by vast thickets of mangroves, home to numerous colonies of crabs and amazing fish- mudskippers. Shallow waters provide excellent habitat for corals. And in temperate waters brown, calcareous and red algae grow (kelp, macrocysts, fucus).

Invertebrate animals: numerous mollusks, a huge number of species of crustaceans, jellyfish. A lot of sea ​​snakes, especially poisonous ones.

Sharks of the Indian Ocean are the special pride of the water area. The largest number of shark species live here: blue, gray, tiger, great white, mako, etc.

Of the mammals, the most common are dolphins and killer whales. And the southern part of the ocean is the natural habitat of many species of whales and pinnipeds: dugongs, fur seals, seals. The most common birds are penguins and albatrosses.

Despite the richness of the Indian Ocean, seafood fishing here is poorly developed. The catch is only 5% of the world's. Tuna, sardines, stingrays, lobsters, lobsters and shrimp are caught.

Indian Ocean exploration

Coastal countries of the Indian Ocean - hotspots ancient civilizations. That is why the development of the water area began much earlier than, for example, the Atlantic or Pacific Ocean. Approximately 6 thousand years BC. The waters of the ocean were already plied by the shuttles and boats of ancient people. The inhabitants of Mesopotamia sailed to the shores of India and Arabia, the Egyptians conducted a lively maritime trade with the countries of East Africa and the Arabian Peninsula.

Key dates in the history of ocean exploration:

7th century AD - Arab sailors compiled detailed navigation maps of the coastal zones of the Indian Ocean, explored the waters near the eastern coast of Africa, India, the islands of Java, Ceylon, Timor, and the Maldives.

1405-1433 - seven sea voyages of Zheng He and exploration of trade routes in the northern and eastern parts of the ocean.

1497 - Vasco de Gama's voyage and exploration of the eastern coast of Africa.

(Expedition of Vasco de Gama in 1497)

1642 - two raids by A. Tasman, exploration of the central part of the ocean and discovery of Australia.

1872-1876 - the first scientific expedition of the English corvette Challenger, studying the biology of the ocean, relief, and currents.

1886-1889 - expedition of Russian explorers led by S. Makarov.

1960-1965 - international Indian Ocean expedition established under the auspices of UNESCO. Study of hydrology, hydrochemistry, geology and ocean biology.

1990s - present day: studying the ocean using satellites, compiling a detailed bathymetric atlas.

2014 - after the crash of a Malaysian Boeing, detailed mapping of the southern part of the ocean was carried out, new underwater ridges and volcanoes were discovered.

Ancient name ocean - Eastern.

Many species of wildlife in the Indian Ocean have an unusual property - they glow. In particular, this explains the appearance of luminous circles in the ocean.

In the Indian Ocean, ships are periodically found in good condition, however, where the entire crew disappears remains a mystery. Over the last century, this happened to three ships at once: the Cabin Cruiser, the tankers Houston Market and Tarbon.

The Indian Ocean is component world ocean. Its maximum depth is 7729 m (Sunda Trench), and its average depth is just over 3700 m, which is second only to the depths of the Pacific Ocean. The size of the Indian Ocean is 76.174 million km2. This is 20% of the world's oceans. The volume of water is about 290 million km3 (together with all the seas).

The waters of the Indian Ocean are light blue in color and have good transparency. This is due to the fact that very few freshwater rivers flow into it, which are the main “troublemakers.” By the way, due to this, the water in the Indian Ocean is much saltier compared to the salinity levels of other oceans.

Location of the Indian Ocean

Most of the Indian Ocean is in the Southern Hemisphere. It is bordered to the north by Asia, to the south by Antarctica, to the east by Australia and to the west by the African continent. In addition, in the southeast its waters connect with the waters of the Pacific Ocean, and in the southwest with the Atlantic Ocean.

Seas and bays of the Indian Ocean

The Indian Ocean does not have as many seas as other oceans. For example, in comparison with the Atlantic Ocean there are 3 times less of them. Most of the seas are located in its northern part. IN tropical zone are: the Red Sea (the saltiest sea on Earth), the Laccadive Sea, the Arabian Sea, the Arafura Sea, the Timor Sea and the Andaman Sea. The Antarctic zone contains the D'Urville Sea, the Commonwealth Sea, the Davis Sea, the Riiser-Larsen Sea, and the Cosmonaut Sea.

The largest bays of the Indian Ocean are the Persian, Bengal, Oman, Aden, Prydz and Great Australian.

Indian Ocean Islands

The Indian Ocean is not distinguished by an abundance of islands. The largest islands of mainland origin are Madagascar, Sumatra, Sri Lanka, Java, Tasmania, Timor. Also, there are volcanic islands such as Mauritius, Regyon, Kerguelen, and coral islands - Chagos, Maldives, Andaman, etc.

The underwater world of the Indian Ocean

Since more than half of the Indian Ocean is located in the tropical and subtropical zones, its underwater world is very rich and diverse in species. The coastal zone in the tropics abounds with numerous colonies of crabs and unique fish- mudskippers. Corals live in shallow waters, and in temperate waters a variety of algae grow - calcareous, brown, red.

The Indian Ocean is home to dozens of species of crustaceans, mollusks and jellyfish. A fairly large number of sea snakes also live in ocean waters, among which there are poisonous species.

The special pride of the Indian Ocean is sharks. Its waters are plied by many species of these predators, namely tiger, mako, gray, blue, large White shark and etc.

Mammals are represented by killer whales and dolphins. The southern part of the ocean is home to several species of pinnipeds (seals, dugongs, seals) and whales.

Despite all the richness of the underwater world, seafood fishing in the Indian Ocean is rather poorly developed - only 5% of the world catch. Sardines, tuna, shrimp, lobsters, rays and lobsters are caught in the ocean.

1. The ancient name of the Indian Ocean is Eastern.

2. In the Indian Ocean, ships are regularly found in good condition, but without a crew. Where he disappears is a mystery. Over the past 100 years, there have been 3 such ships - the Tarbon, the Houston Market (tankers) and the Cabin Cruiser.

3. Many species of the underwater world of the Indian Ocean have a unique property - they can glow. This is what explains the appearance of luminous circles in the ocean.

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