Geographical location of the Indian Ocean: description, features. Indian Ocean on the map
Indian Ocean- third largest. The area of the Indian Ocean is 76.17 million km2, the average depth is 3711 m. The name of the ocean is associated with the name of the Indus River - “irrigator”, “river”.
Characteristic feature geographical location The Indian Ocean is located almost entirely in the Southern Hemisphere and entirely in the Eastern Hemisphere. Its waters wash the shores of Africa, Eurasia, Australia and Antarctica. The Indian Ocean includes 8 seas, the largest being the Arabian. One of the warmest (up to +32 °C) and saltiest (38-42 ‰) seas in the world is the Red. It gets its name from the significant accumulation of algae that gives the water its red color.
Bottom relief The Indian Ocean is diverse. The shelf zone occupies a narrow strip and makes up only 4% total area bottom. The continental slope is very gentle. The ocean floor is crossed by mid-ocean ridges with an average height of approximately 1500 m. They are characterized by rifts and transverse faults, areas of seismic activity. There are individual volcanic mountains and several large basins (Central, Western Australian, etc.). The greatest depth is 7729 m (Sunda Trench).
Climate determined by the location of the main part of the Indian Ocean in the equatorial, subequatorial and tropical climatic zones. The climate of the northern part of the ocean is greatly influenced by land. Seasonal monsoon winds carry from the ocean in summer great amount moisture on land (in the Bay of Bengal region up to 3000 mm per year), in winter they blow from land to the ocean. From the area high pressure The southeast trade wind blows towards the equator. In temperate latitudes, westerly winds prevail great strength accompanied by cyclones. The southern margins of the ocean are cooled by the proximity of Antarctica.
The Indian Ocean is called the "ocean of warm waters" because high temperature water on the surface. Average temperature +17 °C. (Look at climate maps for temperatures and precipitation typical for surface waters.) The Persian Gulf region has highest temperature(+34 °C in August). The least amount of precipitation (100 mm) falls off the coast of Arabia. The average salinity of the waters of the Indian Ocean is 34.7 ‰, the maximum is 42 ‰ (in the north of the Red Sea).
Due to high evaporation from the water surface, low precipitation and lack of river flow, the Red Sea has the highest water salinity in the World Ocean.
The formation of currents is greatly influenced by monsoons. There is a complex system of currents in the Indian Ocean. In the equatorial part of the ocean, the current system is directed clockwise, in the Southern Hemisphere - counterclockwise. (Show currents on a map. Find cold currents.)
Natural resources and environmental problems of the Indian Ocean
The largest oil and gas fields are located in the Persian Gulf. The main areas of modern oil production are the countries of the Persian Gulf: Iran, Iraq, Kuwait, Saudi Arabia, etc. Found at the bottom of ocean basins a large number of ferromanganese nodules, but their quality is lower than in the Pacific Ocean, and they occur at great depths (4000 m).
The fauna of the warm waters of the Indian Ocean is diverse, especially in the northern tropical part: many sharks, sea snakes, and coral polyps. Giant sea turtles are at the stage of extinction. The mangroves of tropical coasts are home to oysters, shrimp, and crabs. Tuna fishing is widespread in the open waters of tropical zones. The Indian Ocean is famous for its pearl fishing. Temperate latitudes are inhabited by toothless and blue whales, seals, elephant seal. The species composition of fish is rich: sardinella, mackerel, anchovy, etc.
On the coast of the Indian Ocean there are dozens of states with total number population of about 2 billion people. These are mainly developing countries. Therefore, the development of the ocean's natural resources is slower than in other oceans. In the development of shipping, the Indian Ocean is inferior to the Atlantic and Pacific. (Explain why.) The Indian Ocean is of great transport importance for the countries of South and South-East Asia, Australia. Intensive transportation of oil and petroleum products from the Persian Gulf has led to a deterioration in water quality and a decrease in stocks of commercial fish and seafood.
Whaling has practically ceased. Warm waters, coral islands, and the beauty of the Indian Ocean attract many tourists here.
Intensive oil production is underway on the shelf of the northwestern Indian Ocean. Important transport routes pass through the Indian Ocean. The ocean holds the third place in the world in terms of maritime transport; the largest oil cargo flows from the Persian Gulf.
Geographical position. The Indian Ocean is located entirely in the eastern hemisphere between Africa in the west, Eurasia in the north, the Sunda Islands and Australia in the east, and Antarctica in the south. The Indian Ocean in the southwest is widely connected with Atlantic Ocean, and in the southeast - with the Quiet. Coastline poorly dissected. There are eight seas in the ocean and there are large bays. There are relatively few islands. The largest of them are concentrated near the coasts of continents.
Bottom relief. As in other oceans, the bottom topography in the Indian Ocean is complex and varied. Among the uplifts on the ocean floor, a system of mid-ocean ridges diverging to the northwest and southeast stands out. The ridges are characterized by rifts and transverse faults, seismicity and submarine volcanism. Between the ridges lie numerous deep-sea basins. The shelf generally has a small width. But it is significant off the coast of Asia.
Mineral resources. There are significant oil and gas deposits in the Persian Gulf, off the coast of Western India and off the coast of Australia. Large reserves of ferromanganese nodules have been discovered at the bottom of many basins. Sedimentary deposits on the shelf contain tin ores, phosphorites, and gold.
Climate. The main part of the Indian Ocean lies in the equatorial, subequatorial and tropical zones, only the southern part covers high latitudes, up to the subantarctic. main feature ocean climate - seasonal monsoon winds in its northern part, which is subject to significant influence from land. Therefore, in the northern part of the ocean there are two seasons of the year - warm, quiet sunny winter and hot, cloudy, rainy, stormy summers. South of 10° S The southeast trade wind prevails. To the south, in temperate latitudes, a strong and stable westerly wind blows. The amount of precipitation is significant in the equatorial belt - up to 3000 mm per year. There is very little rainfall off the coast of Arabia, the Red Sea and the Persian Gulf.
Currents. In the northern part of the ocean, the formation of currents is influenced by the change of monsoons, which rearranges the system of currents according to the seasons of the year: the summer monsoon - in the direction from west to east, the winter - from east to west. In the southern part of the ocean, the most significant are the Southern Trade Wind Current and the Western Wind Current.
Properties of water. The average surface water temperature is +17°C. The slightly lower average temperature is explained by the strong cooling effect of Antarctic waters. The northern part of the ocean warms up well, is deprived of the influx of cold water and is therefore the warmest. In summer, the water temperature in the Persian Gulf rises to +34°C. In the southern hemisphere, water temperatures gradually decrease with increasing latitude. The salinity of surface waters in many areas is higher than average, and in the Red Sea it is especially high (up to 42 ppm).
Organic world. Has much in common with the Pacific Ocean. The species composition of fish is rich and diverse. The northern part of the Indian Ocean is inhabited by sardinella, anchovy, mackerel, tuna, coryphaena, sharks, and flying fish. In southern waters - nototheniids and white-blooded fish; Cetaceans and pinnipeds are found. The organic world of the shelf and coral reefs is especially rich. Thickets of algae line the shores of Australia, South Africa, and islands. There are large commercial aggregations of crustaceans (lobsters, shrimp, krill, etc.). In general, the biological resources of the Indian Ocean are still poorly understood and underutilized.
Natural complexes. The northern part of the ocean lies in the tropical zone. Under the influence of the surrounding land and monsoon circulation, several aquatic complexes are formed in this belt, differing in the properties of water masses. Particularly sharp differences are noted in the salinity of the waters.
In the equatorial zone, the temperature of surface waters remains almost unchanged between seasons. Above numerous bottom rises and near the coral islands in this belt, a lot of plankton develops, and bioproductivity increases. Tuna live in such waters.
Zonal complexes of the southern hemisphere are generally similar in natural conditions to similar belts of the Pacific and Atlantic oceans.
Economic use. Biological resources The Indian Ocean has been used by coastal inhabitants since time immemorial. And to this day, artisanal fisheries and other seafood are preserved important role in the economy of many countries. However, the ocean's natural resources are less exploited than in other oceans. The biological productivity of the ocean is generally low; it increases only on the shelf and continental slope.
The chemical resources of ocean waters are still poorly exploited. Desalination of salt water is being carried out on a large scale in the countries of the Middle East, where there is an acute shortage of fresh water.
Among the mineral resources, oil and gas deposits stand out. In terms of their reserves and production, the Indian Ocean ranks first in the World Ocean. Coastal marine placers contain heavy minerals and metals.
Important transport routes pass through the Indian Ocean. In the development of shipping, this ocean is inferior to the Atlantic and Pacific, but in terms of oil transportation volumes it surpasses them. The Persian Gulf is the main oil export region of the world, and a large cargo flow of oil and petroleum products begins from here. Therefore, systematic monitoring of the condition in this area is necessary. aquatic environment and its protection from oil pollution.
Main questions. What is special about the ocean climate? What role does the Indian Ocean play in economic activity of people?
The Indian Ocean is the third largest. The area of the Indian Ocean is 76.2 million km 2, the average depth is 3711 m. The name of the ocean is associated with the name of the river Indus- “irrigator”, “river”.
Geographical position. The most characteristic feature of the geographical location of the Indian Ocean is that it is located almost entirely in the Southern Hemisphere and entirely in the Eastern Hemisphere. It is surrounded on all sides by Africa and Asia. Australia and Antarctica. There is no connection with the North Arctic Ocean. The ocean includes 8 seas, the largest being Arabian. One of the warmest (up to 32°C) and saltiest seas in the world (38-42 ‰) is Red. It gets its name from the significant accumulation of algae that gives the water a red color. (Fig.)
Relief The bottom of the Indian Ocean is diverse, its formation is associated with the history of the development of the Tethys Ocean. The shelf zone occupies a narrow strip and makes up only 4% of the total bottom area. The continental slope is very gentle. The ocean floor is crossed by mid-ocean ridges with an average height of approximately 1500 m. They are characterized by mid-ocean ridges and transverse faults. Individual volcanic mountains stand out. Greatest depth 7729 m ( Sunda Trench).
Climate determined by its location in the equatorial, subequatorial and tropical climatic zones. Only the southern part covers latitudes up to sub-Antarctic. The climate of the northern part is greatly influenced by land. Seasonal winds monsoons in summer they carry a huge amount of moisture from the ocean to the land (in the Bay of Bengal region up to 3000 mm per year), in winter they blow from the land to the ocean. From the area of high pressure towards the equator a south-easterly blows trade wind. In temperate latitudes they dominate westerly winds of great strength, accompanied by cyclones. The southern margins of the ocean are cooled by the proximity of Antarctica.
The Indian Ocean is called the "ocean of heated waters" due to the high temperature of the water at the surface. Average temperature +17°C. (Look at the climate map for temperatures and precipitation typical for surface waters) The Persian Gulf region has the highest temperature (+34°C in August). The least amount of precipitation (100 mm) falls off the coast of Arabia.
For formation currents Monsoons have a great influence. In the Indian Ocean, unlike the Pacific and Atlantic, in the Northern Hemisphere there is only one ring of currents - clockwise. (Show currents on the map).
The ocean has high salinity due to high evaporation and low precipitation . Average salinity is 34.7 ‰. Maximum salinity in the World Ocean in the Red Sea (41‰ ).
Natural resources and ecological problems. Everyone knows the largest deposits oil And gas in the Persian Gulf: Iran, Iraq, Kuwait, Saudi Arabia, etc. . (Fig.4,5) A large amount of ferromanganese nodules, but their quality is worse than in the Pacific Ocean. They lie deep (4000m).
Animal world The warm waters of the Indian Ocean are diverse, especially northern tropical part: many sharks, sea snakes. This is a desirable habitat for coral polyps and the development of reef structures. (Fig. 1) Unfortunately, giant sea turtles are disappearing. In the mangroves of tropical coasts there are oysters, shrimp, crabs. Fishing is widespread in the open waters of tropical zones tuna. The Indian Ocean is famous for its pearl fishing. IN temperate latitudes live toothless and blue whales, seals, elephant seals. Rich species composition of fish: sardinella, mackerel, anchovy etc. But living organisms in the Indian Ocean are used less than in the Pacific and Atlantic. (rice) The richest organic world is in the Red and Arabian Seas, the Persian and Bengal Bays. Temperate and polar latitudes of the ocean are habitats of large mammals: whales, dolphins. Decorates the ocean kingdom red and brown algae, fucus, kelp.
On the coast of the Indian Ocean there are dozens of states with a total population of about 2 billion people. These are mainly developing countries. Therefore, the development of the ocean's natural resources is slower than in other oceans. In the development of shipping, the Indian Ocean is inferior to the Atlantic and Pacific. Intensive oil transportation has led to a deterioration in water quality and a decrease in stocks of commercial fish and seafood. Whaling has practically ceased. Warm waters, coral islands, and the beauty of the Indian Ocean attract many tourists here.
The northwest Indian Ocean shelf contains the world's richest oil reserves. The Indian Ocean ranks third in the world for maritime transport in general and first for oil transportation (from the Persian Gulf).
1. Describe the geographic location of the ocean. *2. Practical work. Determine the extent of the Indian Ocean at 10° S. w. Draw a conclusion about its size. **3. Create a tourist route along the Indian Ocean coast with a brief description of nature.
Geographical location INDIAN OCEAN, the third largest on Earth (after the Pacific and Atlantic). Located for the most part in the Southern Hemisphere, between Asia in the north, Africa in the west, Australia in the east and Antarctica in the south. Area with seas 76.17 million km 2, water volume 282.7 million km 3, average depth 3711 m
History of ocean exploration. Information about the Indian Ocean began to accumulate since the voyage of Vasco da Gama (). At the end of the 18th century. The first examples of the depths of this ocean were carried out by the English navigator J. Cook.
The bottom topography of the Underwater Central Indian Ridge is divided into a western, shallower part (where the islands of Madagascar, Seychelles, Amirante, Mascarene, etc. are located) and an eastern, deeper part, where south of the island. Java, in the Sunda Trench, maximum depth (7729 m). The bed is divided into basins (West Australian, African-Antarctic, etc.) by ridges, mountains and ramparts.
Features of the nature of the ocean. The climate of the northern part is monsoonal, in the tropical and subtropical latitudes of the southern part trade winds dominate, and in moderate ones there are extratropical cyclones that reach great strength. The prevailing water temperature on the surface is above 20 °C, in the extreme south below 0 °C. Ice forms in Antarctic latitudes and is carried in summer by winds and currents to about south. w.
Salinity is from 32 to 36.5 (in Krasny up to 42). The organic world of the Indian Ocean is diverse. Tropical water masses rich in plankton. There are various types of fish: sardinella, mackerel, sharks. IN warm waters The Indian Ocean is home to giant sea turtles, sea snakes, a lot of cuttlefish and squid, and near Antarctica - whales and seals.
Types of economic activities in the ocean. The natural resources of the Indian Ocean as a whole have not yet been sufficiently studied and developed. The ocean shelf is rich in minerals. In the sedimentary rocks at the bottom of the Persian Gulf there are huge deposits of oil and natural gas. Fishing is developed. Numerous shipping routes pass through the Indian Ocean.
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 the conventional border 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 Passatnoye- 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- a narrow and fast current passing along east coast 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 the globe 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 coastline 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. There are many 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 coastal zones Indian Ocean, exploring the waters near the eastern coast of Africa, India, the islands of Java, Ceylon, Timor, and the Maldives.
1405-1433 - Zheng He's seven sea voyages and exploration 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.
The ancient name of the ocean is 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.