The Indian Ocean
The Indian Ocean lies mostly in the southern hemisphere between Africa, southern Asia, Australia and Antarctica. It was formed by seafloor spreading as Gondwanaland broke up over the last 170 million years. The ocean's main feature is a huge ridge, crossed by many long fractures. The ridge divides into two arms east of Madagascar. One arm runs around Africa and links up with the Atlantic Ridge while the other arm extends south of Australia and eventually links up with the East Pacific rise.
Ocean Facts
Fraction of world ocean: 20%Average depth: 12,740 feet (3,872 m)
Deepest point: 25,344 feet (7,725 m) in the Java Trench