Indian Ocean Third-largest ocean in the world, bounded by Asia (n), Antarctica (s), Africa (w) and Southeast Asia and Australia (e). Known in ancient times as the Erythraean Sea, the Indian Ocean was the first to be extensively navigated. Branches of the ocean include the Arabian Sea, the Bay of Bengal and the Andaman Sea. Its largest islands are Madagascar and Sri Lanka. The average depth is 4000m (13,000ft) although there is a Mid-Oceanic Ridge, extending from Asia to Antarctica; several of its peaks emerge as islands. The deepest part is the Java Trench, reaching 7725m (25,344ft). The climate of the nearby land masses is strongly influenced by the ocean's winds and currents. There are three wind belts: the monsoons, which pick up moisture from the ocean, bringing heavy rainfall to w India and Southeast Asia; the se trade winds; and the prevailing westerly winds, bringing tropical storms. The currents are governed by these winds, the seasonal shift of the monsoon dictating the flow of water n of the Equator. Area: c.73,600,000sq km (28,400,000sq mi).

Indian Ocean One of the world's major oceans, lying between Africa, India, and Australia. It has a surface area of 77 million km² and an average depth of 3872 m. The ocean receives a great deal of sediment from three of the world's major rivers (the Ganges, the Indus, and the Brahmaputra).

Indian Ocean One of the world's major oceans, lying between Africa, India, and Australia. It has a surface area of 77 million km² and an average depth of 3872 m. The ocean receives a great deal of sediment from three of the world's major rivers (the Ganges, the Indus, and the Brahmaputra).