Indian Ocean

Indian Ocean
Blue Marble Eastern Hemisphere.jpg
A composite satellite image centred on the Indian Ocean
Indian Ocean surface.jpg
The ocean-floor of the Indian Ocean is divided by spreading ridges and crisscrossed by aseismic structures
LocationIndian subcontinent, Southeast Asia, Western Asia, Northeast Africa, East Africa, Southern Africa and Australia
Coordinates20°S 80°E / 20°S 80°E / -20; 80
Max. length9,600 km (6,000 mi) (Antarctica to Bay of Bengal)[1]
Max. width7,600 km (4,700 mi) (Africa to Australia)[1]
Surface area70,560,000 km2 (27,240,000 sq mi)
Average depth3,741 m (12,274 ft)
Max. depth7,258 m (23,812 ft)
Shore length166,526 km (41,337 mi)[2]
SettlementsDurban, Mumbai, Perth, Colombo, Padang, Maputo
1 Shore length is not a well-defined measure.

The Indian Ocean is the third-largest of the world's oceanic divisions, covering 70,560,000 km2 (27,240,000 sq mi) or 19.8% of the water on the Earth's surface.[4] It is bounded by Asia to the north, Africa to the west, and Australia to the east. To the south it is bounded by the Southern Ocean or Antarctica, depending on the definition in use.[5]


A 1747 map of Africa with the Indian Ocean referred to as the Eastern Ocean
A 1658 naval map by Janssonius depicting the Indian Ocean, India and Arabia.

The Indian Ocean has been known by its present name since at least 1515, when the Latin form Oceanus Orientalis Indicus ("Indian Eastern Ocean") is attested. The root name, India, originated as the Ancient Greek and Roman name for the region around the Indus River.[6]

It was usually called Sindhu Mahasagara "great sea of the Sindhu" by people in Ancient Indian cultures.

The Indian Ocean was also known as the Eastern Ocean, a term was that was still in use during the mid-18th century (see map).[6] Conversely, Chinese explorers in the Indian Ocean, during the 15th century, called it the Western Oceans.[7] The ocean has also been known as the Hindu Ocean and Indic Ocean in various languages.

In Ancient Greek geography the region of the Indian Ocean known to the Greeks was called the Erythraean Sea.[8]

A relatively new concept of an "Indian Ocean World" and attempts to rewrite its history has resulted in new proposed names, such as 'Asian Sea' and 'Afrasian Sea'.[9]