Indian Ocean

Geography

Location: body of water between Africa, Antarctica, Asia, and Australia

Map references: World

Area:
total area: 73.6 million sq km
comparative area: slightly less than eight times the size of the US; third-largest ocean (after the Pacific Ocean and Atlantic Ocean, but larger than the Arctic Ocean)
note: includes Arabian Sea, Bass Straight, Bay of Bengal, Great Australian Bight, Gulf of Oman, Persian Gulf, Red Sea, Strait of Malacca, and other tributary water bodies

Coastline: 66,526 km

International disputes: some maritime disputes (see littoral states)

Climate: northeast monsoon (December to April), southwest monsoon (June to October); tropical cyclones occur during May/June and October/November in the northern Indian Ocean and January/February in the southern Indian Ocean

Terrain: surface dominated by counterclockwise gyre (broad, circular system of currents) in the southern Indian Ocean; unique reversal of surface currents in the northern Indian Ocean, low atmospheric pressure over southwest Asia from hot, rising, summer air results in the southwest monsoon and southwest-to-northeast winds and currents, while high pressure over northern Asia from cold, falling, winter air results in the northeast monsoon and northeast-to-southwest winds and currents; ocean floor is dominated by the Mid-Indian Ocean Ridge and subdivided by the Southeast Indian Ocean Ridge, Southwest Indian Ocean Ridge, and Ninety East Ridge; maximum depth is 7,258 meters in the Java Trench

Natural resources: oil and gas fields, fish, shrimp, sand and gravel aggregates, placer deposits, polymetallic nodules

Environment:
current issues: endangered marine species include the dugong, seals, turtles, and whales; oil pollution in the Arabian Sea, Persian Gulf, and Red Sea
natural hazards: ships subject to superstructure icing in extreme south near Antarctica from May to October
international agreements: NA

Note: major chokepoints include Bab el Mandeb, Strait of Hormuz, Strait of Malacca, southern access to the Suez Canal, and the Lombok Strait

Government

Digraph: XO

Economy

Overview: The Indian Ocean provides major sea routes connecting the Middle East, Africa, and East Asia with Europe and the Americas. It carries a particularly heavy traffic of petroleum and petroleum products from the oilfields of the Persian Gulf and Indonesia. Its fish are of great and growing importance to the bordering countries for domestic consumption and export. Fishing fleets from Russia, Japan, Korea, and Taiwan also exploit the Indian Ocean, mainly for shrimp and tuna. 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. Beach sands rich in heavy minerals and offshore placer deposits are actively exploited by bordering countries, particularly India, South Africa, Indonesia, Sri Lanka, and Thailand.

Industries: based on exploitation of natural resources, particularly fish, minerals, oil and gas, fishing, sand and gravel

Transportation

Ports: Bombay (India), Calcutta (India), Colombo (Sri Lanka), Durban (South Africa), Jakarta (Indonesia), Madras (India), Melbourne (Australia), Richard's Bay (South Africa)

Communications

Telephone system:
international: submarine cables from India to United Arab Emirates and Malaysia, and from Sri Lanka to Djibouti and Indonesia