Read this paragraph on Indian Ocean: Paragraph on Indian Ocean !
With an estimated area of about 73,442,700 sq km the Indian Ocean is the third largest ocean in the world after the Pacific Ocean and the Atlantic Ocean.
Although the Indian Ocean is much smaller in size than the Pacific and the Atlantic Oceans, yet it is of immense importance for us because it is located in the south of India.
This is the only ocean in the world to be named after the name of a country, i.e., Indian Ocean after India. In a way, it is just half an ocean because it does not open out northwards in the Arctic Ocean. It is bounded by South Asia in the north, Indonesian islands and Australia in the east and by Africa in the west.
The meridian of Cape of Tasmania (147°E) forms the boundary line between the Indian and the Pacific Oceans while the meridian of Cape Town (18° 22’E) forms the dividing line between the Atlantic Ocean and the Indian Ocean.
In the south, it extends to the Antarctic continent from where it merges with the Atlantic and the Pacific. The International Hydrographic Organisation has recognised the coast of Antarctica as the southern extreme of the Indian Ocean. Tropic of Cancer forms its northernmost limit.
The Indian Ocean has great strategic importance for India. The “landlocked” nature of the Indian Ocean has given India a commanding position. From the eastern coast of Africa and the shores of the Persian Gulf to the Strait of Malacca, no other country rivals India’s dominant location in the Indian Ocean.
The strategic import of this ocean is further enhanced by the fact that it is accessible from the west and the east through narrow straits only. The Red Sea and the Persian Gulf are the narrow outlets in the west while in the east; there are the Strait of Malacca and the Timore and Arafura Sea.
The Indian Ocean has limited outlets. Before the opening of the Suez Canal in 1869, the only contact of littoral states of the Indian Ocean with the western countries was via Cape of Good Hope by circumnavigating the whole continent of Africa.
On the eastern side there are two outlets—one through the islands of Indonesia and the second is the south of Australia. The Indian Ocean can be choked any time by controlling these outlets. Since the Indian Ocean and the countries surrounding it are very rich in natural resources, such a possibility has considerably enhanced the geopolitical strategy of this ocean.
In spite of above mentioned geopolitical limitations, the Indian Ocean has never been a barrier between the countries. On the contrary it has served as a great linkage between the countries lying on its coasts and even further beyond. We can reach West Asia, Africa and Europe from the west coast and South East Asia, Far East and Oceania from the eastern coast.
The Indian Ocean, thus, bridges a gap between east and west. This ocean is encircled by 46 countries (27 littoral including Australia, 7 islands countries and 12 landlocked countries as recognised by the U.N.), with great diversity in almost every respect; shape, size, people, resources, economy, polity, culture, etc. (Fig. 1.10)
The Indian Ocean is endowed with rich variety of natural resources of which mineral and power resources as well as food resources are very important. Some of the resources are briefly described as under:
Marine aggregates comprise sand, gravel or shell deposits and are used primarily in construction industry. They are, at present the most important commodities mined offshore, both quantitatively and by value.
They are mainly found on the continental shelves. Offshore calcareous deposits are formed by fragmentation of shells by waves and currents. These are used for manufacturing cement.
Placer deposits are concentrations of heavy, resilient, and chemically resistant minerals eroded from existing ore bodies by mechanical weathering. Such deposits include native gold, native platinum, tin, titanium, magnetite (iron), zirconium, monozite (thorium) and gemstones. In the Indian Ocean, such placers are found along the coasts of Sri Lanka, India, Australia, Malaysia and Indonesia.
Sri Lanka, India and Australia have titanium sands, whereas Malaysia and Indonesia have tin deposits. Indonesia is one of the main areas in the world where offshore placers are mined. Primary tin deposits occur in granitic rocks onshore and heavy minerals extend offshore.
Polymetallic nodules are those which contain several metals, the important metals being manganese, copper, nickel, cobah, etc. They occur in many shapes, sizes and forms and are generally friable.
Manganese nodules were first discovered on the 1872-76 scientific voyage of Challenger, but systematic exploration and detailed studies only started in late 1950s when it was realised that nodules might be a source of nickel, copper and cobalt.
Several investigations in the mid 1960s reported finding enrichment of manganese and iron in the sediments of wide areas of the ocean floor on the East Pacific Rise axis, and since then similar enrichments have been found in Indian Ocean also, especially along the mid-Indian rise.
India has obtained the technology of exploiting these mineral nodules from the ocean beds. The United Nations has granted permission to India to exploit the polymetallic nodules over an area of 1, 50,000 sq km in the Indian Ocean. India is the first country to obtain such a right. The National Institute of Oceanography, Goa has played a leading role in the research and development of this mining technique.
Metalliferous nodules containing zinc, copper and silver have been discovered in Red Sea. Seafloor phosphorite contains phosphate mineral which is used for the manufacture of phosphate fertilizers and certain phosphate based chemicals.
Seafloor phosphorite was first discovered as nodules in dredge samples obtained from the Agulhas Bank off South Africa during the Chellenger Expedition of 1872-76 and have since been found elsewhere. They occur mostly on the continental margins and upper parts of the continental slopes at depths of less than 500 metres. They are normally confined to the zone between 40°N and 40°S latitudes.
In the Indian Ocean phosphorite deposits occur along the coast of Arabian Peninsula, east coast of India in the Bay of Bengal, near Andaman and Nicobar Islands and in the south of Sri Lanka. Phosphorites occur widely on Agulhas Bank off South Africa. It has become one of the most intensely studied areas of the world. The total reserves are estimated at 450 million tonnes.
Estimates of reserves suggest that recoverable nickel and copper are of the same order as known land economic resources. But the current level of technology is not competent enough to exploit these resources.
Specialised mining systems have to be developed to recover the nodules without lifting the underlying sediment from depths in excess of 4000 metres. The environmental conditions of potential mine sites and possibilities of mineral extraction have been ascertained.