Indian Ocean

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Map of the Indian Ocean. Contrary to what is shown here, the Java Sea is normally not counted as part of the Indian Ocean.

The Indian Ocean is 74.9 million sq km area (approximately 14.7% of the Earth) is the third largest ocean of the Earth and with temperatures of 22 ° C to 28 ° C, the warmest ocean in the world. It has a volume of approx. 291.9 million km³, the maximum sea ​​depth is 7,290 meters. Most of the Indian Ocean is in the southern hemisphere . It borders on the continents of Africa , Asia and Australia as well as on the Atlantic Ocean , the Pacific Ocean and along the southern 60 ° latitude on the Antarctic Ocean .

The abbreviation Indic (from Latin Oceanus Indicus ), formed analogously to the Atlantic and Pacific , is rarely used.


Within the Indian Ocean or on its sea ​​floor there are lower thresholds and a high, elongated mid-ocean ridge : the central Indian ridge , which runs roughly in the middle from north to south through the ocean.

Furthermore, there are deep-sea basins as well as deep-sea channels and various sea ​​lows in the Indian Ocean . In 2019, an expedition that wanted to reach the deepest points of all oceans with the submersible Limiting Factor examined the possible areas with a lander and a fan- assisted echo sounder from the Kongsberg group . Since then a 7,290 m deep sea in the Sunda Trench has been assumed to be the deepest point . Previously, the Diamantina Low was partially considered to be the lowest point at over 8000 m, but the measurements identified the Dordrecht Low at only 7100 m as the deepest point of the Diamantina Fracture Zone .

Three continental plates make up a larger proportion of the sea floor of the Indian Ocean: the African plate in the west, the Australian plate in the east and the Antarctic plate in the south. In addition, there are parts of the Arabian plate , the Indian plate and the Eurasian plate in the north (see the map under plate tectonics ).



The marginal seas , gulfs and straits of the Indian Ocean include (clockwise from west to north to east and south-east):

description Area
in km²
Average depth
in m
Mozambique Strait Strait between Mozambique (Africa) and the island of Madagascar
Arabian Sea 3,862,000 Between the Horn of Africa , the Arabian Peninsula and the West Indian coast
Gulf of Aden 530,000 Part of the Arabian Sea
Bab al-Mandab Strait between the Gulf of Aden and the Red Sea
Red Sea 438,000 538 With transition to the Suez Canal in the north
Gulf of Oman 181,000 Part of the Arabian Sea
Strait of Hormuz Strait between the Gulf of Oman and the Persian Gulf
Persian Gulf 235,000 The foothills of the Persian Gulf in Iran form the northernmost point of the Indian Ocean
Lakkadive Lake 786,000 1.929 With Gulf of Mannar and Palk Strait between India and Sri Lanka
Bay of Bengal 2,171,000 2,600 Rand Sea on the east coast of India
Andaman Sea 797,700 870 Between the Andaman Islands and the west coasts of Burma and Thailand
Strait of Malacca Connection from the Andaman Sea to the South China Sea
Timor Sea 61,500 North of Australia
Great Australian Bay 484,000 South of Australia

Bordering states


From south to north these are:

South Africa , Mozambique , Tanzania , Kenya , Somalia , Djibouti , Eritrea , Sudan and Egypt .

(The latter three states are indirectly connected to this ocean via the Red Sea as the marginal sea of ​​the Indian Ocean.)


Clockwise from west to north to east and southeast:

Saudi Arabia , Yemen , Oman , United Arab Emirates , Qatar , Bahrain , Kuwait , Iraq , Iran , Pakistan , India , Bangladesh , Myanmar , Thailand , Malaysia , Indonesia and East Timor .

Israel and Jordan each have a small stretch of coast on the Gulf of Aqaba and are indirectly connected to the Indian Ocean via the Red Sea. They can therefore also be counted among the neighboring countries.



Island states

Topographic-bathymetric map
Ocean currents in the Indian Ocean

The politically independent island states Indonesia , Madagascar and Sri Lanka are located within the Indian Ocean . Independent archipelagos are the Comoros (with the French overseas department Mayotte ), the Seychelles and the Maldives . In addition to the main island, the island of Rodrigues and the two Agalega islands, the island state of Mauritius also includes other uninhabited islands such as the Cargados-Carajos Islands . The Mascarene archipelago includes most of the islands of Mauritius (not the Agalegas) as well as the French overseas department of La Réunion .

Other islands and archipelagos

The Socotra archipelago belongs to the Republic of Yemen . The Zanzibar Archipelago is part of Tanzania . The Indian union territory of the Andaman and Nicobar Islands form the Andaman and Nicobar archipelago of the same name . The archipelago Lakkadiven and Amindiven as well as the island Minicoy together form the Indian union territory Lakshadweep .

The Chagos Archipelago with the main island of Diego Garcia is the last British territory in the Indian Ocean . The island of Ko Phuket is part of Thailand.

To Australia include the Christmas Island , the Cocos Islands , Heard and McDonald Islands and the Ashmore and Cartier Islands .

Other islands belonging to the Indian Ocean are the Kerguelen, part of the French Southern and Antarctic Territories, and the South African Prince Edward Islands in the far west .

Environmental policy in the coastal states of the Indian Ocean influences the ecology of the sea. Environmental policy is not a high priority in many neighboring countries. On this beach in the Tanzanian Dar es Salaam, washed up and left rubbish is not disposed of.

Sea ports and port cities on the Indian Ocean




2004 Indian Ocean earthquake

Epicenter of the quake

An earthquake in the Indian Ocean on December 26, 2004 had devastating effects. It had a magnitude of 9.2 on the Richter scale . The epicenter was in the sea, near the northwest tip of Sumatra . The huge tsunami triggered by the quake caused more than 300,000 deaths. Mainly affected countries were Indonesia , Thailand , India and Sri Lanka . The waves even reached Somalia, 5200 km away .

See also


  • Edward A. Alpers: The Indian Ocean in World History. Oxford University Press, Oxford et al. 2014.
  • Peter Lehr: Indian Ocean Region - Illusion or Reality? (Dissertation at the University of Heidelberg 2004).
  • The Indian Ocean from a historical perspective . In: Stephan Conermann (Ed.): Asia and Africa: Contributions from the Center for Asian and African Studies (ZAAS) at the Christian Albrechts University in Kiel . tape 1 . EB-Verlag, Hamburg 1998, ISBN 3-930826-44-5 (contributions partly in German and partly in English).
  • Manfred Leier: World Atlas of the Oceans . With the depth maps of the world's oceans. Frederking and Thaler, Munich 2001, ISBN 3-89405-441-7 , p. 188-207 .

Web links

Wiktionary: Indic  - explanations of meanings, word origins, synonyms, translations
Commons : Indian Ocean  - Collection of images, videos and audio files

Individual evidence

  1. Warmest ocean. Retrieved on April 13, 2021 (German).
  2. Ben Taub, Paolo Pellegrin: Thirty-six Thousand Feet Under the Sea: The explorers who set one of the last meaningful records on earth . In: The New Yorker . May 10, 2020.
  3. Heather Stewart, Alan Jamieson, Cassie Bongiovanni: Exploring the Deepest Points on Planet Earth: Report on The Five Deeps Expedition ., June 18, 2019.
  4. Heather A. Stewart, Alan J. Jamieson: The five deeps: The location and depth of the deepest place in each of the world's oceans. In: Earth-Science Reviews 197, October 2019, 102896, doi: 10.1016 / j.earscirev.2019.102896 .

Coordinates: 22 °  S , 76 °  E