Terrain: surface dominated by a major gyre (broad, circular system of currents) in the southern Indian Ocean and a unique reversal of surface currents in the northern Indian Ocean; ocean floor is dominated by the Mid-Indian Ocean Ridge and subdivided by the Southeast Indian Ocean Ridge, Southwest Indian Ocean Ridge, and Ninetyeast Ridge
major surface currents: the counterclockwise Indian Ocean Gyre comprised of the warm Agulhas and East Madagascar Currents in the west, the South Indian Current in the south, the cold West Australian Current in the east, and the South Equatorial Current in the north; a distinctive annual reversal of surface currents occurs 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 clockwise currents, while high pressure over northern Asia from cold, falling, winter air results in the northeast monsoon and northeast-to-southwest winds and counterclockwise currents
Definition: This entry contains a brief description of the topography.
Source: CIA World Factbook - This page was last updated on January 20, 2018
