Indian Ocean

Indian Ocean, third largest ocean, c.28,350,000 sq mi (73,427,000 sq km), extending from S Asia to Antarctica and from E Africa to SE Australia; it is c.4,000 mi (6,400 km) wide at the equator. It constitutes about 20% of the world's total ocean area. The Indian Ocean is connected with the Pacific Ocean by passages through the Malay Archipelago and between Australia and Antarctica; and with the Atlantic Ocean by the expanse between Africa and Antarctica and by the Suez Canal. Its chief arms are the Arabian Sea (with the Red Sea, the Gulf of Aden, and the Persian Gulf), the Bay of Bengal, and the Andaman Sea. The continental shelf of the Indian Ocean is narrow. Madagascar and Sri Lanka, the largest islands in the ocean, are structurally parts of the continents as are Socotra, the Andaman Islands, and the Nicobar Islands; the Seychelles and the Kerguelen Islands are exposed tops of submerged ridges. The Laccadives, the Maldives, and the Chagos are low coral islands, and Mauritius and Réunion are high volcanic cones. The floor of the Indian Ocean has an average depth of c.11,000 ft (3,400 m). The Mid-Oceanic Ridge, a broad submarine mountain range extending from Asia to Antarctica, divides the Indian Ocean into three major sections—the African, Antardis, and Australasian. The ridge rises to an average height of c.10,000 ft (3,000 m), and a few peaks emerge as islands. A large rift, an extension of the eastern branch of the Great Rift Valley that runs through the Gulf of Aden, extends along most of its length (see seafloor spreading). The Mid-Oceanic Ridge, along with other submarine ridges, encloses a series of deep-sea basins (abyssal plains). The greatest depth (25,344 ft/7,725 m) is in the Java Trench, S of Java, Indonesia. The Indian Ocean receives the waters of the Zambezi, Tigris-Euphrates, Indus, Ganges-Brahmaputra, and Irrawady rivers. The surface waters of the ocean are generally warm, although close to Antarctica pack ice and icebergs are found. The Indian Ocean has two water circulation systems—a regular counterclockwise southern system (South Equatorial Current, Mozambique Current, West Wind Drift, West Australian Current) and a northern system, the Monsoon Drift, whose currents are directly related to the seasonal shift of monsoon winds. The southwest monsoon draws moisture from the Indian Ocean and drops heavy rainfall on the Indian subcontinent and Southeast Asia.

The Columbia Encyclopedia, 6th ed. Copyright© 2018, The Columbia University Press.

Indian Ocean: Selected full-text books and articles

Imperial Connections: India in the Indian Ocean Arena, 1860-1920 By Thomas R. Metcalf University of California Press, 2007
The Age of Reconnaissance By J. H. Parry World Pub. Co., 1963
Librarian's tip: Chap. 8 "Africa and the Indian Ocean"
The Lost Cities of Africa By Basil Davidson Little, Brown, 1959
Librarian's tip: Chap. 6 "Traders of the Indian Ocean"
Medieval Arab Navigation on the Indian Ocean: Latitude Determinations By Clark, Alfred The Journal of the American Oriental Society, Vol. 113, No. 3, July-September 1993
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
Land and Maritime Zones of Peace in International Law By Surya P. Subedi Clarendon Press, 1996
Librarian's tip: "The Indian Ocean as a Zone of Peace" begins on p. 1
Oceans Governance and Maritime Strategy By David Wilson; Dick Sherwood Allen & Unwin, 2000
Dynamics of Regional Politics: Four Systems on the Indian Ocean Rim By W. Howard Wriggins; F. Gause Gregory III; Terrence P. Lyons; Evelyn Colbert Columbia University Press, 1992
Asia and Western Dominance: A Survey of the Vasco Da Gama Epoch of Asian History, 1498-1945 By K. M. Panikkar George Allen & Unwin, 1953
Librarian's tip: Chap. 1 "India and the Indian Ocean"
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