The Indian Ocean is the third largest ocean of the world. It covers about 20% of the water on the Earth’s surface. It is bounded on the north by South Asia; on the west by East Africa; on the east by Indo-China, the Sunda Islands, and Australia; and on the south by the Southern Ocean. It is the only ocean to be named after the name of a country, i.e India. The Indian Ocean is the warmest ocean in the world.
The Indian Ocean is nearly 10,000 kilo- metres wide at the southern tips of Africa and Australia. Its area is 73,556,000 square kilo- metres, including the Red Sea and the Persian Gulf. The ocean’s volume is estimated to be 292,131,000 cubic kilo- metres. Island nations within the ocean are Madagascar, Reunion Island, Comoros, Seychelles, Maldives, Mauritius and Sri Lanka.
The African, Indian, and Antarctic crustal plates converge in the Indian Ocean at the Rodrigues Triple Point. The ocean’s continental shelves are narrow, averaging 200 kilometres in width. An exception is found off Australia’s western coast, where the shelf width exceeds 1,000 kilometres. The average depth of the ocean is 3,890 metres (12,760 ft). Its deepest point, 7258 meters deep, is in the Java Trench. The major choke points include Bab el Mandeb, Strait of Hormuz, the Lombok Strait, the Strait of Malacca and the Palk Strait. Seas include Gulf of Aden, Andaman Sea, Arabian Sea, Bay of Bengal, Great Australian Bight, Laccadive Sea, Gulf of Mannar, Mozambique Channel, Gulf of Oman, Persian Gulf, Red Sea, and other tributary water bodies. It is artificially connected to the Mediterranean Sea via the Suez Canal, accessible via the Red Sea. Among the few large rivers flowing into the Indian Ocean are the Zambezi, Shatt al-Arab, Indus, Ganges, Brahmaputra, Jubba and Ayeyarwady River.
The Indian Ocean provides major sea routes connecting the Middle East, Africa, and East Asia with Europe and America. It carries a particularly heavy traffic of petroleum and petroleum products from the oil fields of the Persian Gulf and Indonesia. Large reserves of hydrocarbons are being tapped in the offshore areas of Saudi Arabia, Iran, India, and Western Australia. An estimated 40% of the world’s offshore oil production comes from the Indian Ocean. Fishing is of great and growing importance to the bordering countries for domestic consumption and export. Fishing fleets from Russia, Japan, South Korea, and Taiwan also exploit the Indian Ocean, mainly for shrimp and tuna. Endangered marine species include the dugong, seals, turtles, and whales.
The Indian Ocean is far calmer and thus opened to trade earlier than the Atlantic or Pacific Oceans. The powerful monsoons also meant ships could easily sail west early in the season, then wait a few months and return eastwards. This allowed Indonesian peoples to cross the Indian Ocean to settle in Madagascar.
In the second or first century BC, Eudoxus of Cyzicus was the first Greek to cross the Indian Ocean. Hippalus is said to have discovered the direct route from Arabia to India around this time. During the first and second centuries intensive trade relations developed between Rome, Egypt and the Tamil kingdoms of the Cheras, Cholas and Pandyas in Southern India. From 1405 to 1433, Admiral Zheng led large fleets of the Ming Dynasty on several voyages to the Indian Ocean and reached the coastal country of East Africa. In 1497, Vasco da Gama rounded the Cape of Good Hope and became the first European to sail to India. The Dutch East India Company (1602–1798) sought control of trade with the East across the Indian Ocean. France and Britain established trade companies for the area. The opening of the Suez Canal in 1869 revived European interest in the East. On December 26, 2004, the countries surrounding the Indian Ocean were hit by a tsunami caused by the earthquake. The waves resulted in more than 2, 26,000 deaths and over 1 million people were left homeless.