Indian Ocean exploration. Geographical location, history of discovery and development
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The first ideas about the nature of the Indian Ocean developed among the ancient peoples who inhabited its shores and beyond (in Southern Europe, North Africa, Southwest and East Asia).
For trade and military purposes, they sailed through various parts of the ocean.
In the V-IV millennium BC. e. The Sumerians sailed through the Persian Gulf and out into the Arabian Sea. Sailors-Phoenicians for six centuries BC. and, having sailed from the Eritrean (Red) Sea, they circled Africa and after 3 years returned home, having passed the Pillars of Hercules ( strait of Gibraltar). The Mediterranean peoples actively used the monsoon winds for their sea voyages in the Indian Ocean.
Greeks and Romans already in the 1st century. n. e. paved the sea route through the Bay of Bengal and established a connection with China.
Obviously, the ocean area was mastered by the sailors of India, Indonesia and other Arabs in the 7th-8th centuries. sailed a lot in the Indian Ocean. They summarized the information received and “go nature in handwritten books. In 1466-1472. Tver merchant Afanasy Nikitin traveled to India and reached the Indian Ocean (crossed the Arabian Sea). In his travel notes "Journey Beyond the Three Seas" a vivid and truthful description is given not only of his life in this country, but also of trade routes there from of Eastern Europe.
In the XV-XVI centuries. the period of intensive development of the ocean by Europeans begins. In 1497-1498. The Portuguese Vasco da Gama opened the sea route to India along the western coast of Africa. Following the Portuguese, Dutch, French, Spanish, and English navigators rush into the Indian Ocean, covering its various parts.
The first oceanographic research along with geographical descriptions and clarification of the coastline of the Indian Ocean, they begin to conduct sea expeditions with late XVIII V.
So, while swimming D.
Cook (1772-1775), the water temperature was measured to a depth of 200 m. Oceanographic work in the Indian Ocean was also carried out by the first Russian round-the-world expedition of I.F. Kruzenshtern and Yu.F. Lisyansky (1803-1806), during expeditions under the leadership of O.
E. Kotzebue (1815-1818 and 1823-1826). A great contribution to the development of science, including the geography of the ocean, was the work of Ch.
Darwin.
In the XIX - early XX century. a broader study of the ocean began. The development of deep-sea research was facilitated by the work on laying underwater telegraph cables in the Arabian Sea and the Bay of Bengal (1857-1869). During the round-the-world expedition aboard the Challenger (1873-1876), complex oceanological research was carried out, including hydrological, geological and biological observations. In 1898-1899. Germany organized a special deep-sea expedition in the Indian Ocean.
She is credited with the beginning of the discovery of the East Indian and Arabian-Indian ridges. In 1906, the soundings of another German vessel led to the discovery of the Yavan (Zonda) deep-water trench.
Since the middle of the XX century. work in the Indian Ocean has become purposeful. Significant results have been brought by oceanographic studies carried out naval detachments diesel-electric ships "Ob" and "Lena" under the program of the International Geophysical Year (1955-1957).
The research vessel "Vityaz" (1959-1962, 1965) made a significant contribution to the study of the Indian Ocean.
A major event was the discovery of the West Indian Ridge and its study by US oceanologists (1959-1960).
Indian Ocean
One of the first civilizations that had the skill of navigation, and lived near the Indian Ocean, were the Sumerians, who settled in Mesopotamia in the Persian Gulf.
Sea routes between India and Arabia existed as early as the 3rd millennium BC. In addition, it is known that in the 7th-6th centuries BC. the coastal waters of the ocean were mastered by the Phoenicians, who managed to go around Africa, having sailed from the Red Sea.
On the border of our era, the ships of the most developed peoples - Indians, Chinese and Arabs gradually moved along the coast of the ocean, opening up new ways for trade and military purposes.
It is known that already in the 8th-10th centuries the sea route from China to India was well known and actively used. But for Europeans, the Eastern Ocean (the early name of the Indian) for many centuries was an unknown part of the planet.
But already in the IV century BC. the famous Alexander the Great reached its shores together with the army after a campaign in India. However, after him, for many hundreds of years, only small ships of the ancient Greeks visited these waters for trade with India and China, and their trade turnover was small.
Marco Polo became the first European who, in the 13th century, not only sailed across the Indian Ocean from the Malay Peninsula to the Persian Gulf, but also described the voyage in detail in the Book of the Diversity of the World.
Almost two hundred years later, in his book “Journey Beyond Three Seas”, the Russian traveler, merchant Afanasy Nikitin, who arrived in India by sea through the Arabian Sea in 1469, wrote about the ocean.
With the advent of modern documentary sources about those distant shores, the Europeans could not but have an interest in the development of Asian lands by sea.
Although the main reason that drove the researchers was, of course, not simple curiosity, but the desire to earn money by reaching the fabulous riches of Hindustan.
The most famous failed attempt to find a short sea route to India was the voyage of Christopher Columbus. Unlike Columbus, the Portuguese calculated everything correctly ...
And it is the Portuguese who are considered the first Europeans of our era, who "officially" opened the expanses of the Indian Ocean to Europeans. The first was Bartolomeu Dias, who in 1488 rounded Africa from the south on his ship.
To the east, he managed to advance only to the mouth of the river. Great Fish in present-day South Africa. However, he returned to his homeland with invaluable information - there is a sea route to India.
Under the leadership of Dias, after 9 years, the great expedition of Vasco da Gama was equipped.
So, at the end of the 15th - beginning of the 16th centuries, Europeans received information about the east coast of Africa, and were finally able to reach Indian Calicut by sea.
They also encountered and were forced to interact with the Arab navigators, who had mastered the Indian Ocean a long time ago.
From the 19th century to the present, oceanographic studies of the Indian Ocean have been carried out with ever more advanced devices.
Of course, its bottom and shores have long been clarified, but it is still too early to consider the history of the study completed.
The Indian Ocean began to form about 145 million years ago, between parts of the split supercontinent Gondwana (future Hindustan, Madagascar, Australia and Antarctica). The ocean between different parts world, which subsequently began to be populated by people, was doomed to become a crossroads of trade routes for the most ancient peoples who lived on its shores.
One of the first civilizations that had the skill of navigation, and lived near the Indian Ocean, were the Sumerians, who settled in Mesopotamia in the Persian Gulf.
Sea routes between India and Arabia existed as early as the 3rd millennium BC. In addition, it is known that in the 7th-6th centuries BC. the coastal waters of the ocean were mastered by the Phoenicians, who managed to go around Africa, having sailed from the Red Sea.
On the border of our era, the ships of the most developed peoples - Indians, Chinese and Arabs gradually moved along the coast of the ocean, opening up new ways for trade and military purposes.
It is known that already in the 8th-10th centuries the sea route from China to India was well known and actively used.
History of the Indian Ocean
But for Europeans, the Eastern Ocean (the early name of the Indian) for many centuries was an unknown part of the planet.
But already in the IV century BC. the famous Alexander the Great reached its shores together with the army after a campaign in India. However, after him, for many hundreds of years, only small ships of the ancient Greeks visited these waters for trade with India and China, and their trade turnover was small.
Marco Polo became the first European who, in the 13th century, not only sailed across the Indian Ocean from the Malay Peninsula to the Persian Gulf, but also described the voyage in detail in the Book of the Diversity of the World.
Almost two hundred years later, in his book “Journey Beyond Three Seas”, the Russian traveler, merchant Afanasy Nikitin, who arrived in India by sea through the Arabian Sea in 1469, wrote about the ocean.
With the advent of modern documentary sources about those distant shores, the Europeans could not but have an interest in the development of Asian lands by sea.
Although the main reason that drove the researchers was, of course, not simple curiosity, but the desire to earn money by reaching the fabulous riches of Hindustan.
The most famous failed attempt to find a short sea route to India was the voyage of Christopher Columbus. Unlike Columbus, the Portuguese calculated everything correctly ...
And it is the Portuguese who are considered the first Europeans of our era, who "officially" opened the expanses of the Indian Ocean to Europeans.
The first was Bartolomeu Dias, who in 1488 rounded Africa from the south on his ship. To the east, he managed to advance only to the mouth of the river. Great Fish in present-day South Africa. However, he returned to his homeland with invaluable information - there is a sea route to India.
Under the leadership of Dias, after 9 years, the great expedition of Vasco da Gama was equipped.
So, at the end of the 15th - beginning of the 16th centuries, Europeans received information about the east coast of Africa, and were finally able to reach Indian Calicut by sea.
They also encountered and were forced to interact with the Arab navigators, who had mastered the Indian Ocean a long time ago.
The next stage in the history of the Indian Ocean can be considered the 18th-19th centuries, when its waters began to be of interest not only as "roads", but also as sources of valuable resources.
First, the Englishman James Cook, and then other navigators different countries(including Russians) began to study depths, currents, water properties and other parameters.
The Indian Ocean began to form about 145 million years ago, between parts of the split supercontinent Gondwana (future Hindustan, Madagascar, Australia and Antarctica).
Indian Ocean exploration
The ocean, located between different parts of the world, which later began to be inhabited by people, was doomed to become a crossroads of trade routes for the most ancient peoples who lived on its shores.
One of the first civilizations that had the skill of navigation, and lived near the Indian Ocean, were the Sumerians, who settled in Mesopotamia in the Persian Gulf.
Sea routes between India and Arabia existed as early as the 3rd millennium BC. In addition, it is known that in the 7th-6th centuries BC. the coastal waters of the ocean were mastered by the Phoenicians, who managed to go around Africa, having sailed from the Red Sea.
On the border of our era, the ships of the most developed peoples - Indians, Chinese and Arabs gradually moved along the coast of the ocean, opening up new ways for trade and military purposes.
It is known that already in the 8th-10th centuries the sea route from China to India was well known and actively used. But for Europeans, the Eastern Ocean (the early name of the Indian) for many centuries was an unknown part of the planet.
But already in the IV century BC.
the famous Alexander the Great reached its shores together with the army after a campaign in India. However, after him, for many hundreds of years, only small ships of the ancient Greeks visited these waters for trade with India and China, and their trade turnover was small. Marco Polo became the first European who, in the 13th century, not only sailed across the Indian Ocean from the Malay Peninsula to the Persian Gulf, but also described the voyage in detail in the Book of the Diversity of the World.
Almost two hundred years later, in his book “Journey Beyond Three Seas”, the Russian traveler, merchant Afanasy Nikitin, who arrived in India by sea through the Arabian Sea in 1469, wrote about the ocean.
With the advent of modern documentary sources about those distant shores, the Europeans could not but have an interest in the development of Asian lands by sea.
Although the main reason that drove the researchers was, of course, not simple curiosity, but the desire to earn money by reaching the fabulous riches of Hindustan.
The most famous failed attempt to find a short sea route to India was the voyage of Christopher Columbus. Unlike Columbus, the Portuguese calculated everything correctly ...
And it is the Portuguese who are considered the first Europeans of our era, who "officially" opened the expanses of the Indian Ocean to Europeans.
The first was Bartolomeu Dias, who in 1488 rounded Africa from the south on his ship. To the east, he managed to advance only to the mouth of the river. Great Fish in present-day South Africa. However, he returned to his homeland with invaluable information - there is a sea route to India.
Under the leadership of Dias, after 9 years, the great expedition of Vasco da Gama was equipped. So, at the end of the 15th - beginning of the 16th centuries, Europeans received information about the east coast of Africa, and were finally able to reach Indian Calicut by sea.
They also encountered and were forced to interact with the Arab navigators, who had mastered the Indian Ocean a long time ago.
The next stage in the history of the Indian Ocean can be considered the 18th-19th centuries, when its waters began to be of interest not only as "roads", but also as sources of valuable resources.
First, the Englishman James Cook, and then other navigators from different countries (including Russians) began to study depths, currents, water properties and other parameters.
From the 19th century to the present, oceanographic studies of the Indian Ocean have been carried out with ever more advanced devices.
Of course, its bottom and shores have long been clarified, but it is still too early to consider the history of the study completed.
Introduction
I chose this topic for several reasons. In my opinion, the Indian Ocean and its margins are of great scientific interest. From the point of view of geology, a lot of interesting objects can be distinguished here. Such as: the Sunda Island Arc, the triple junction point of Rodrigues Island, the Bengal alluvial fan, the Karoo deposits on the east coast of Africa, and much more.
From a Research Perspective this region I must say that the Indian Ocean and its shores remain poorly understood. Despite numerous studies, many controversial issues remain. One of them is the question of the origin of the ocean. Personally, I found several points of view on this matter, and this interested me. It's about about the age of the ocean, disputes arising on this issue are related to the finds of remains related to different period, in layers with assumed equal ages.
In order to fully understand the reasons for choosing this particular topic, its relevance and prospects, it is necessary to raise the question of what goals were set for the research, the result of which is presented here. In my opinion, any scientific activity should be of some public benefit. In the case of coastal exploration, the benefits are clear. Since ancient times, when expeditions were devoted to mapping hitherto unexplored territories, the study of the outskirts of both the Indian and any other ocean has been a source of progress, as a result, the development of trade and diplomatic relations. IN modern world research is even more important. Having received data on food and mineral resources, humanity can begin to rationalize their use. Whether it's oil production, natural gas or simply fishing, all this is directly related to the geology of the outskirts.
My goal was to write a term paper on the chosen topic.
My task was to study the continent-ocean transition zones, using the example of the Indian Ocean, by reading the literature on this topic. The task was also to process, comprehend the acquired knowledge and convey it in their own words.
Historical overview
Indian Ocean exploration
The Indian Ocean is the third largest ocean on earth. The Indian Ocean washes three continents at once: Africa from the east, Asia from the south, Australia from the north and northwest.
The name Indian Ocean is found already at the beginning of the sixteenth century by Schöner under the name Oceanus orientalis indicus, in contrast to the Atlantic Ocean, then known as Oceanus occidentalis (http://www.vehi.net/brokgauz/).
The history of the study of the Indian Ocean can be divided into three periods: from merchant shipping and military campaigns of ancient times to the beginning of deep-sea research in the last quarter of the 18th century. early XIX century.; from research expeditions of the last quarter of the 17th - 19th centuries to the first complex oceanographic expeditions of the last quarter of the 19th century; from these expeditions to complex international studies of our time, inclusive.
In the first period, the peoples who lived on the shores of the Indian Ocean traveled for trading purposes, creating maps along the way and gaining knowledge about currents, winds and other navigation conditions.
One of the brightest events is the journey of the Tver merchant Athanasius Nikitin to India in 1466-1472. A great contribution was also made by D. Cook, who sailed along the coast on the ships "Resolution" and "Adventure" in 1772-1775, during his journey he obtained data on the temperature of the water to a depth of 180 m. Oceanographic research was also carried out by I.F. . Kruzenshtern and Yu.F. Lisyansky (1803-1806). The next important contribution was the research of Charles Darwin, who received geological, ecological and biological data. At the same time, Darwin formed the theory of the origin of atolls, which is still valid. The first deep-sea soundings of the Indian Ocean (up to 5000 m) were probably made by D. Ross in 1840-1843. The development of deep-sea research was also facilitated by the work on laying underwater telegraph cables (http://ru.wikipedia.org/wiki/).
The beginning of the second period of the study of the Indian Ocean was marked in 1873-1876 by the first round-the-world oceanographic expedition of the Challenger, led by Professor Wyville Thomson, a member of the British Royal Society. This expedition carried out comprehensive research, including physical, chemical, biological and geological observations.
This was followed by a series of studies, already of a narrower focus, it is significant that a large number of countries that are leaders in science participated in the study of the Indian Ocean. Subsequent studies were of a narrower nature (for example, gravimetric studies on submarines in 1923 by Vening-Mason).
Expedition activities within the framework of the International Geophysical Year (IGY) 1957-1959. opened a new stage in the study of the oceans. Although this expedition paid the most attention to the Atlantic and Pacific Oceans, the Indian also did not stand aside. The largest expedition at that time was the program of the International Indian Ocean Expedition (IIOE), which covered almost the entire Indian Ocean (1960-1965) with observation. It is very pleasant that 10 Soviet ships took part in this program (http://geoman.ru/books/item/f00/s00/z0000051/st005.shtml).
Exploration of the continental margins of the Indian Ocean
A detailed study of the continental margins has a relatively short history (about 50 years), even despite the many efforts made, many aspects remain unclear and contradictory. Submarine continental margins are among the areas in which it is most difficult to work, since they are characterized by significant fluctuations in the depths of the bottom and the configuration of the layers of the sedimentary cover and crust, large differences physical properties and significant changes in the composition of rocks within the same region.
Ancient underwater margins are even more difficult to identify and study, because they are characterized by severe deformations. Therefore, there is a wide range of possible, acceptable interpretations and concepts of origin and evolution. It is much easier to explore deep ocean basins, where the water column reaches 4-5 km, which serve as a filter to eliminate the influence of problematic areas on geophysical curves, the structure of such areas is much simpler than those that are closer to the coast.
Presentation on the theme "Indian Ocean" in geography for schoolchildren. Consists of nine slides. In the presentation, the Indian Ocean is considered according to the lesson plan: geographical location, history of ocean exploration, features of the nature of the ocean, types economic activity in the ocean. The project was completed by Evgenia Yagodorova and Daria Malyutkina.
Fragments from the presentation:
Lesson plan:
- Geographical position.
- From the history of ocean exploration.
- Features of the nature of the ocean.
- Types of economic activity in the ocean.
Map of the Indian Ocean
The Indian Ocean has a peculiar position on the planet: most of it lies in the southern hemisphere. In the north, it is bounded by Eurasia and has no connection with the Arctic Ocean.
Who discovered and explored the Indian Ocean?
The description of sailing routes on the ocean was the first to be made by the Arabs. Information about the Indian Ocean began to accumulate from the time of the voyages of Vasco da Gama (1497-1499). At the end of the 18th century The first measurements of the depth of this ocean were made by the English navigator J. Cook.
Features of the nature of the ocean
The structure of the bottom topography is complex. Mid-ocean ridges divide the ocean floor into three parts. In the western part, a ridge stretches, connecting south of Africa with the Mid-Atlantic Ridge. The center of the ridge is characterized by deep faults, areas of earthquakes and volcanism at the bottom of the ocean. faults earth's crust continue in the Red Sea and come ashore. A feature of the climate is the seasonal monsoon winds in the northern part of the ocean, which is located in the subequatorial belt and is significantly influenced by land. Monsoons have a huge impact on weather conditions in the northern part of the ocean.
In the south, the ocean experiences the cooling influence of Antarctica; here lie the most severe regions of the ocean. The properties of water masses are associated with the characteristics of the climate. The northern part of the ocean warms up well, is deprived of the influx of cold waters and is therefore the warmest. The water temperature here is higher (up to +30) than at the same latitudes in other oceans. To the south, the water temperature drops. The salinity of ocean waters at the surface is generally higher than the salinity oceans, and in the Red Sea it is especially high (up to 42%). In the northern part of the ocean, the formation of currents is influenced by the seasonal change of winds. Monsoons change the direction of water movement, causing their vertical mixing. Rebuild the flow system. In the south the currents are integral part general scheme currents of the oceans.
Organic world of the Indian Ocean
Tropical water masses are rich in plankton, which is especially rich in single-celled algae. Lots of plankton glowing at night organisms. Diversity of fish species: sardinella, mackerel, sharks. Shelf areas and shallow waters near coral reefs are especially rich in life. Turtles and sea snakes live in warm waters. Of the mollusks, there are many cuttlefish and squid, and near Antarctica - whales and seals.
Types of economic activity
The ocean shelf is rich in minerals. In the strata of sedimentary rocks at the bottom of the Persian Gulf, huge deposits of oil create the danger of water pollution. Fishing is also developed. Numerous shipping routes pass through the Indian Ocean. There are especially many sea roads in the northern part of the ocean, where small sailing ships are still used. The direction of their movement is associated with the monsoons.
The project was completed by Evgenia Yagodorova and Daria Malyutkina.
The first ideas about the nature of the Indian Ocean were formed by the old peoples who inhabited its shores and beyond. For trading and combat purposes, they bathed in different parts of the ocean.
In the V-IV millennia BC. e. the Sumerians sailed in accordance with the Persian Gulf and went into the Arabian Sea. Phoenician sailors from 6 centuries BC e., having sailed from the Reddish Sea, rounded Africa and after 3 years returned home, having passed the Strait of Gibraltar. The Mediterranean peoples actively used the monsoon winds for their own sea voyages in the Indian Ocean.
Greeks and Romans more closely in the 1st century AD. e. laid a sea route through the Bay of Bengal and established an association with China. Of course, the sailors of India, Indonesia and other Arabs mastered the ocean in the 7-8 centuries. many sailed in accordance with the Indian Ocean. They summarized the acquired information about its nature in handwritten books. In 1466-1472. Tver merchant Bessmertny Nikitin traveled to India and conquered the Indian Ocean.
In his travel notes "Journey from Beyond the 3rd Sea" a colorful and honest reflection is given not only of his life in this country, but also of the merchant's way there from Eastern Europe. In the 15-16 centuries. a period of active development of the ocean by Europeans begins. In 1497-1498. The Portuguese Vasco po Gama opened the sea route to India through the western coast of Africa. Due to the Portuguese, Dutch, French, Spanish, English sailors, including its various shares, are striving for the Indian Ocean.
The first oceanographic studies, along with geographical descriptions and clarification of the coastal strip of the Indian Ocean, began to live on sea expeditions from the end of the 18th century.
So, during the bathing of D. Cook (1772-1775), the water temperature was measured at a depth of 200 meters. Oceanographic work in the Indian Ocean was carried out by another Russian round-the-world expedition of I.F. Kruzenshtern and Yu.F. Lisyansky (1803-1806), during the expedition led by O.E. years), there were many discoveries. A huge contribution to the formation of science in the quantity and geography of the ocean, the works of Charles Darwin appeared.
In the 19th - early 20th century, the most extensive study of the ocean unfolded. The development of deep-sea studies was promoted by the work of laying underwater telegraph cables in the Arabian Sea and the Bay of Bengal (1857-1869). During the round-the-world expedition on the Challenger (1873-1876), group oceanological studies were carried out, including hydrological, geological and biological supervision.
In 1898-1899. Germany organized a special deep-sea expedition in the Indian Ocean. She owns the award of the source of the disclosure of the East Indian and Arabian-Indian ridges. In 1906, the measurements of another German ship led to the invention of the Yavan (Zonda) deep-water trench.
Since the middle of the 20th century, work in the Indian Ocean has become purposeful. Significant results were brought by oceanographic research carried out by marine teams of diesel-electric ships "Ob" and "Lena" under the program of the International Geophysical Year (1955-1957). The research vessel "Vityaz" (1959-1962, 1965) made a significant contribution to the study of the Indian Ocean.
A major event was the discovery of the West Indian Ridge and its study by oceanologists C
SHA. Thanks to the identification of the missing southwestern branch of the Mid-Indian Ridge, the existence of a single global system mid-ocean ridges.
INTRODUCTION
Indian Ocean
Above the blackness of your depths
Wonderful lights burned
And your swell went heavily,
Exploding the fire of silent mines.
She blinded our eyes
And we turned pale in the fast light
And blue fiery nets
Flowing on slow waves.
And again, noisy and deep,
You rebelled and caught fire -
And staggered from star to star
Great cane unsteady fore.
Behind the shaft, the oncoming shaft ran
With a fiery monsoon breath,
And the tail of a diamond scorpion
I trembled over your blackness.
Ivan Bunin
Geographical location, history of discovery and development
The nature of the Indian Ocean, to a greater extent than other oceans, has features of tropical exoticism. Most salient feature The geographical position of the Indian Ocean lies in the fact that 84% of its area is located in the Southern Hemisphere. It has no direct connection with the Arctic Ocean.
The Indian Ocean is located between Africa, Asia, Australia and Antarctica, i.e. It is largely limited by land, but at the same time it has water borders for a large extent. The western boundary of the Indian Ocean is the meridian 20? o.d. on the segment between Antarctica (Princess Ranghil Coast) and Cape Agulhas at the southern tip of Africa. In the northeast, the ocean is limited by the northern entrance to the Strait of Malacca, the southwestern and southern shores of the Greater and Lesser Sunda Islands, the southwestern coast of New Guinea to the mouth of the Benebec River, from here along the water to Cape York (the northern tip of Australia). In the east, the boundary of the ocean runs along the coast of Australia to Cape Southeast, then crosses the Bass Strait to the northwestern tip of Tasmania, then along its western coast to Cape South, from which it follows meridian 147? o.d. When identifying the Southern Ocean, the southern boundary of the Indian Ocean is drawn along the line of the Antarctic convergence, which lies between latitudes 48? (at 20? East) and 54? (at 150? East).
If we take the coast of Antarctica as the southern border of the Indian Ocean, then the ocean has an area of 76.2 million km 2, a volume of 282.6 million km 3, an average depth of 3711 m, and a maximum depth of 7729 m (Zonda Trench). The Indian Ocean has approximately the same length in latitude (11450 km along the latitude 10° S) and in longitude (10180 km along the meridian 60° E). The southern tropic passes approximately at an equal distance from the northern and southern boundaries of the ocean. The Indian Ocean in the northern part is significantly separated by continents and archipelagos. Only in the southern part does it communicate widely with the Atlantic and Pacific Oceans, which generally ensures its good water exchange.
There are many islands in the Indian Ocean. The largest of them - Madagascar, Sri Lanka, Greater Sunda - are of continental origin and are located near the continents. Volcanic islands lie in the open part of the ocean: Comoros (the largest of them is Ngazidzha with an active Kargala volcano), Mascarene (the largest island is Reunion), Andaman, Nicobar, Seychelles. Coral islands are especially numerous in the Indian Ocean, most of which are typical atolls. A typical example is the atoll of Diego Garcia. It is an almost continuous ring of land, open only at a slight attraction in the northern part.
In addition to atolls, many coral islands in their formation are associated with the development of barrier and coastal coral reefs. Such islands form archipelagos, such as Bahrain and Tanzanian, which includes the islands of Zanzibar, Pemba and smaller ones. Many islands in the Indian Ocean, especially coral ones, are characterized by modern coastal erosion, which changes their outlines.
Six seas belong to the Indian Ocean: the Red, Arabian, Andaman and Laccadive wash the coast of Southwest and South Asia, while the Timor and Arafura are off the northern coast of Australia.
The Indian Ocean seas have many common features. With the exception of the Red Sea, they occupy a marginal position. All seas warm up well, they have rather small seasonal changes in surface water temperature. The most significant feature of these seas is the pronounced monsoons, which determine the main features of the nature of the seas. At the same time, each of them noticeably expresses its own individuality, which creates its own “portrait” of the sea.
The history of Indian Ocean exploration can 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 traveled in the northern part of the Indian Ocean in 3000-1000 BC, and ended with the voyage of James Cook, who in 1772-75 penetrated south to 71 ° south latitude. The second period was marked by the beginning of deep-sea research, first conducted by Cook in 1772 and continued by Russian and foreign expeditions. The main Russian expeditions were - O. Kotzebue on the "Rurik" (1818) and Pallena on the "Cyclone" (1858-59). The third period is characterized by complex oceanographic research.
The penetration of Europeans (Portuguese, then the Dutch, French and British) into the Indian Ocean basin dates back to the 16-17 centuries, and by the middle of the 19 century, Great Britain secured most of its coasts and islands, which exported from here the most important raw materials and food products for its economy. . Naval (and later air) bases were established at all entrances to the Indian Ocean: in Atlantic Ocean- Simonstown, in Pacific Ocean- Singapore, to the Red Sea - Aden, on the approaches to India - Trincomalee. In the northeastern part of the Indian Ocean there were colonies of France, the Netherlands (Netherlands India), Portugal.
After the end of World War II (1939-1945), the collapse of the colonial system of imperialism introduced fundamental amendments to the political map of the Indian Ocean basin.