Ocean bounded by Asia, Africa and Australia

The World Factbook[4] (blue area), and as defined by the IHO (black outline – excluding marginal waterbodies). The indian Ocean, according to the CIA ( blue sky area ), and as defined by the IHO ( total darkness outline – excluding borderline waterbodies ). The Indian Ocean is the third-largest of the world ‘s five oceanic divisions, covering 70,560,000 km2 ( 27,240,000 sq nautical mile ) or 19.8 % of the water on Earth ‘s surface. [ 5 ] 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 southerly Ocean or Antarctica, depending on the definition in use. [ 6 ] Along its core, the indian Ocean has some big marginal or regional seas such as the Arabian Sea, the Laccadive Sea, the Somali Sea, Bay of Bengal, and the Andaman Sea.

Reading: Indian Ocean – Wikipedia

etymology [edit ]

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 ( “ amerind Eastern Ocean ” ) is attested, named for India, which projects into it. It was sooner known as the Eastern Ocean, a term that was even in use during the mid-18th hundred ( see map ), as opposed to the Western Ocean ( Atlantic ) before the Pacific was surmised. [ 7 ] conversely, taiwanese explorers in the amerind Ocean during the fifteenth hundred called it the Indian Oceans. [ 8 ] The ocean has besides been known as the Hind Mahasagar and Indic Ocean in respective languages. [ citation needed ] In Ancient Greek geography, the indian Ocean area known to the Greeks was called the Erythraean Sea. [ 9 ] In ancient indian textbook it was called “ Ratnakara ”. [ citation needed ]

geography [edit ]

The ocean-floor of the amerind Ocean is divided by spreading ridges and crisscrossed by aseismic structures A complex satellite trope centred on the indian Ocean

extent and data [edit ]

The borders of the amerind Ocean, as delineated by the International Hydrographic Organization in 1953 included the southern Ocean but not the borderline seas along the northerly rim, but in 2000 the IHO delimited the Southern Ocean individually, which removed waters south of 60°S from the amerind Ocean but included the northern marginal seas. [ 10 ] [ 11 ] Meridionally, the indian Ocean is delimited from the Atlantic Ocean by the 20° east meridian, running south from Cape Agulhas, and from the Pacific Ocean by the acme of 146°49’E, running confederacy from the southernmost point of Tasmania. The northernmost extent of the indian Ocean ( including marginal seas ) is approximately 30° north in the Persian Gulf. [ 11 ] The indian Ocean covers 70,560,000 km2 ( 27,240,000 sq secret intelligence service ), including the Red Sea and the irani Gulf but excluding the southerly Ocean, or 19.5 % of the world ‘s oceans ; its volume is 264,000,000 km3 ( 63,000,000 copper michigan ) or 19.8 % of the earth ‘s oceans ‘ volume ; it has an average depth of 3,741 thousand ( 12,274 foot ) and a maximum astuteness of 7,906 thousand ( 25,938 foot ). [ 5 ] All of the indian Ocean is in the Eastern Hemisphere and the center of the Eastern Hemisphere, the 90th meridian east, passes through the Ninety East Ridge .

Coasts and shelves [edit ]

In contrast to the Atlantic and Pacific, the indian Ocean is enclosed by major landmasses and an archipelago on three sides and does not stretch from pole to pole, and can be likened to an embayed ocean. It is centered on the indian Peninsula. Although this subcontinent has played a significant function in its history, the indian Ocean has foremostly been a cosmopolitan stagecoach, interlinking divers regions by innovations, trade wind, and religion since early in human history. [ 12 ] The active agent margins of the amerind Ocean have an average depth ( land to shelf break [ 13 ] ) of 19 ± 0.61 kilometer ( 11.81 ± 0.38 mi ) with a maximum astuteness of 175 km ( 109 mile ). The passive voice margins have an average depth of 47.6 ± 0.8 kilometer ( 29.58 ± 0.50 michigan ). [ 14 ] The modal width of the slopes of the continental shelves are 50.4–52.4 km ( 31.3–32.6 secret intelligence service ) for active and passive margins respectively, with a maximal depth of 205.3–255.2 km ( 127.6–158.6 myocardial infarction ). [ 15 ] In agreement of the Shelf break, besides known as Hinge zone, the Bouguer gravity ranges from 0 to 30 mGals that is unusual for a continental region of around 16 km blockheaded sediments. It has been hypothesized that the “ Hinge zone may represent the relict of continental and proto-oceanic crustal boundary formed during the rifting of India from Antarctica. ” [ 16 ] Australia, Indonesia, and India are the three countries with the longest shorelines and exclusive economic zones. The continental shelf makes up 15 % of the indian Ocean. More than two billion people live in countries bordering the indian Ocean, compared to 1.7 billion for the Atlantic and 2.7 billion for the Pacific ( some countries border more than one ocean ). [ 2 ]

Rivers [edit ]

The indian Ocean drain basin covers 21,100,000 km2 ( 8,100,000 sq security service ), virtually identical to that of the Pacific Ocean and one-half that of the Atlantic basin, or 30 % of its ocean surface ( compared to 15 % for the Pacific ). The indian Ocean drain washbasin is divided into roughly 800 individual basins, half that of the Pacific, of which 50 % are located in Asia, 30 % in Africa, and 20 % in Australasia. The rivers of the indian Ocean are shorter on average ( 740 kilometer ( 460 secret intelligence service ) ) than those of the other major oceans. The largest rivers are ( club 5 ) the Zambezi, Ganges – Brahmaputra, Indus, Jubba, and Murray rivers and ( ordering 4 ) the Shatt al-Arab, Wadi Ad Dawasir ( a desiccated river system on the Arabian Peninsula ) and Limpopo rivers. [ 17 ] After the dissolution of East Gondwana and the formation of Himalayas, the Ganges-Brahmaputra rivers flowed into the populace ‘s largest Bengal delta. [ 16 ]

Marginal seas [edit ]

Marginal seas, gulf, bays and straits of the amerind Ocean include : [ 11 ] Along the east coast of Africa, the Mozambique Channel separates Madagascar from mainland Africa, while the Sea of Zanj is located north of Madagascar. On the northerly coast of the Arabian Sea, Gulf of Aden is connected to the Red Sea by the strait of Bab-el-Mandeb. In the Gulf of Aden, the Gulf of Tadjoura is located in Djibouti and the Guardafui Channel separates Socotra island from the Horn of Africa. The northern end of the Red Sea terminates in the Gulf of Aqaba and Gulf of Suez. The indian Ocean is artificially connected to the Mediterranean Sea without ship lock in through the Suez Canal, which is accessible via the Red Sea. The arabian Sea is connected to the Persian Gulf by the Gulf of Oman and the Strait of Hormuz. In the Persian Gulf, the Gulf of Bahrain separates Qatar from the Arabic Peninsula. Along the west seashore of India, the Gulf of Kutch and Gulf of Khambat are located in Gujarat in the northerly goal while the Laccadive Sea separates the Maldives from the southern tip off of India. The Bay of Bengal is off the east coast of India. The Gulf of Mannar and the Palk Strait separates Sri Lanka from India, while the Adam ‘s Bridge separates the two. The Andaman Sea is located between the Bay of Bengal and the Andaman Islands. In Indonesia, the alleged indonesian Seaway is composed of the Malacca, Sunda and Torres Straits. The Gulf of Carpentaria of located on the australian north slide while the Great Australian Bight constitutes a big contribution of its southern coast. [ 18 ] [ 19 ] [ 20 ]

climate [edit ]

During summer, warm continental masses draw damp air from the indian Ocean hence producing heavy rain. The process is reversed during winter, resulting in dry conditions. several features make the indian Ocean unique. It constitutes the core of the large-scale Tropical Warm Pool which, when interacting with the atmosphere, affects the climate both regionally and globally. Asia blocks heat export and prevents the public discussion of the amerind Ocean thermocline. That continent besides drives the indian Ocean monsoon, the strongest on Earth, which causes large-scale seasonal variations in ocean currents, including the reversal of the Somali Current and amerind Monsoon Current. Because of the amerind Ocean Walker circulation there are no continuous equatorial easterlies. Upwelling occurs near the Horn of Africa and the arabian Peninsula in the Northern Hemisphere and north of the craft winds in the Southern Hemisphere. The indonesian Throughflow is a unique equatorial joining to the Pacific. [ 21 ] The climate north of the equator is affected by a monsoon climate. potent northeast winds blow from October until April ; from May until October south and west winds prevail. In the Arabian Sea, the violent Monsoon brings rain to the indian subcontinent. In the southerly hemisphere, the winds are generally milder, but summer storms near Mauritius can be austere. When the monsoon winds change, cyclones sometimes strike the shores of the Arabian Sea and the Bay of Bengal. [ 22 ] Some 80 % of the total annual rain in India occur during summer and the region is so dependent on this rain that many civilisations perished when the Monsoon failed in the by. The huge unevenness in the amerind Summer Monsoon has besides occurred pre-historically, with a strong, moisture phase 33,500–32,500 BP ; a weak, dry phase 26,000–23,500 BC ; and a very watery phase 17,000–15,000 BP, corresponding to a series of dramatic global events : Bølling-Allerød, Heinrich, and Younger Dryas. [ 23 ]
Air pollution in South Asia spread over the Bay of Bengal and beyond. The indian Ocean is the warmest ocean in the world. [ 24 ] long-run ocean temperature records show a rapid, continuous warming in the indian Ocean, at about 1.2 °C ( 34.2 °F ) ( compared to 0.7 °C ( 33.3 °F ) for the ardent pool region ) during 1901–2012. [ 25 ] Research indicates that human induced greenhouse thaw, and changes in the frequency and order of magnitude of El Niño ( or the indian Ocean Dipole ), events are a trigger to this solid heating in the indian Ocean. [ 25 ] South of the Equator ( 20-5°S ), the amerind Ocean is gaining heat from June to October, during the austral winter, while it is losing heat from November to March, during the austral summer. [ 26 ] In 1999, the indian Ocean Experiment showed that fossil fuel and biomass burn off in South and Southeast Asia caused air contamination ( besides known as the Asian brown cloud ) that reach angstrom far as the Intertropical Convergence Zone at 60°S. This befoulment has implications on both a local and ball-shaped scale. [ 27 ]

oceanography [edit ]

40 % of the sediment of the indian Ocean is found in the Indus and Ganges fans. The oceanic basins adjacent to the continental slopes largely contain terrigenous sediments. The ocean south of the diametric front ( roughly 50° south latitude ) is high in biological productiveness and dominated by non-stratified sediment composed by and large of siliceous oozes. Near the three major mid-ocean ridges the ocean floor is relatively young and consequently plain of sediment, except for the Southwest Indian Ridge due to its ultra-slow circulate rate. [ 28 ] The ocean ‘s currents are chiefly controlled by the monsoon. Two large gyres, one in the northern hemisphere flowing clockwise and one south of the equator moving counterclockwise ( including the Agulhas Current and Agulhas Return Current ), constitute the dominant flow blueprint. During the winter monsoon ( November–February ), however, circulation is reversed north of 30°S and winds are weakened during winter and the transitional periods between the monsoons. [ 29 ] The indian Ocean contains the largest submarine fans of the populace, the Bengal Fan and Indus Fan, and the largest areas of gradient terraces and rift valleys. [ 30 ] The inflow of deep body of water into the indian Ocean is 11 Sv, most of which comes from the Circumpolar Deep Water ( CDW ). The CDW enters the indian Ocean through the Crozet and Madagascar basins and crosses the Southwest indian Ridge at 30°S. In the Mascarene Basin the CDW becomes a deep western boundary current before it is met by a re-circulated arm of itself, the North indian Deep Water. This blend water partially flows north into the Somali Basin whilst most of it flows clockwise in the Mascarene Basin where an oscillatory flow is produced by Rossby waves. [ 31 ] Water circulation in the indian Ocean is dominated by the Subtropical Anticyclonic Gyre, the easterly extension of which is blocked by the Southeast Indian Ridge and the 90°E Ridge. Madagascar and the Southwest Indian Ridge branch three cells south of Madagascar and off South Africa. North Atlantic Deep Water reaches into the amerind Ocean south of Africa at a depth of 2,000–3,000 megabyte ( 6,600–9,800 foot ) and flows north along the easterly continental slope of Africa. Deeper than NADW, Antarctic Bottom Water flows from Enderby Basin to Agulhas Basin across deep channels ( < 4,000 m ( 13,000 foot ) ) in the Southwest Indian Ridge, from where it continues into the Mozambique Channel and Prince Edward Fracture Zone. [ 32 ] North of 20° south latitude the minimum surface temperature is 22 °C ( 72 °F ), exceeding 28 °C ( 82 °F ) to the east. Southward of 40° south latitude, temperatures shed cursorily. [ 22 ] The Bay of Bengal contributes more than half ( 2,950 km3 or 710 cu security service ) of the runoff water to the indian Ocean. chiefly in summer, this runoff flows into the arabian Sea but besides south across the Equator where it mixes with clean seawater from the indonesian Throughflow. This shuffle fresh water joins the South Equatorial Current in the southern tropical indian Ocean. [ 33 ] Sea open salt is highest ( more than 36 PSU ) in the arabian Sea because dehydration exceeds precipitation there. In the Southeast Arabian Sea salt drops to less than 34 PSU. It is the lowest ( c. 33 PSU ) in the Bay of Bengal because of river overflow and haste. The indonesian Throughflow and precipitation results in lower salt ( 34 PSU ) along the Sumatran west seashore. Monsoonal variation results in east transportation of salty water from the Arabian Sea to the Bay of Bengal from June to September and in westerly tape drive by the East India Coastal Current to the arabian Sea from January to April. [ 34 ] An indian Ocean garbage patch was discovered in 2010 covering at least 5 million straight kilometres ( 1.9 million squarely miles ). Riding the southern amerind Ocean Gyre, this whirlpool of fictile drivel constantly circulates the ocean from Australia to Africa, down the Mozambique Channel, and back to Australia in a period of six years, except for debris that gets indefinitely stuck in the center of the coil. [ 35 ] The drivel while in the indian Ocean will, according to a 2012 study, decrease in size after several decades to vanish completely over centuries. Over several millennia, however, the global system of garbage patches will accumulate in the North Pacific. [ 36 ] There are two amphidromes of opposite rotation in the indian Ocean, credibly caused by Rossby roll generation. [ 37 ] Icebergs stray as far union as 55° confederacy latitude, alike to the Pacific but less than in the Atlantic where iceberg reach up to 45°S. The volume of crisphead lettuce passing in the amerind Ocean between 2004 and 2012 was 24 Gt. [ 38 ] Since the 1960s, anthropogenetic heating of the ball-shaped ocean combined with contributions of fresh water from retreating land frosting causes a ball-shaped surface in sea flat. Sea horizontal surface increases in the indian Ocean excessively, except in the south tropical indian Ocean where it decreases, a convention most likely caused by rising levels of greenhouse gases. [ 39 ]

Marine life [edit ]

A dolphin off western Australia and a pour of surgeonfish near Maldives Islands represents the long-familiar, exotic animal of the affectionate parts of the indian Ocean. King Penguins on a beach in the Crozet Archipelago near Antarctica attract fewer tourists. Among the tropical oceans, the western indian Ocean hosts one of the largest concentrations of phytoplankton blooms in summer, due to the potent monsoon winds. The monsoonal wind forcing leads to a potent coastal and exposed ocean upwelling, which introduces nutrients into the upper berth zones where sufficient light up is available for photosynthesis and phytoplankton production. These phytoplankton blooms support the marine ecosystem, as the base of the marine food web, and finally the larger fish species. The indian Ocean accounts for the second-largest share of the most economically valuable tuna catch. [ 40 ] Its pisces are of great and growing importance to the surround countries for domestic consumption and export. Fishing fleets from Russia, Japan, South Korea, and Taiwan besides exploit the indian Ocean, chiefly for shrimp and tuna. [ 3 ] inquiry indicates that increasing ocean temperatures are taking a toll on the marine ecosystem. A study on the phytoplankton changes in the indian Ocean indicates a decline of up to 20 % in the marine plankton in the indian Ocean, during the past six decades. The tuna catch rates have besides declined 50–90 % during the past half-century, by and large ascribable to increased industrial fisheries, with the ocean warming adding promote stress to the pisces species. [ 41 ] Endangered and vulnerable marine mammals and turtles : [ 42 ]
80 % of the indian Ocean is open ocean and includes nine bombastic marine ecosystems : the Agulhas Current, Somali Coastal Current, Red Sea, Arabian Sea, Bay of Bengal, Gulf of Thailand, West Central Australian Shelf, Northwest Australian Shelf, and Southwest Australian Shelf. Coral reefs overlay c. 200,000 km2 ( 77,000 sq nautical mile ). The coasts of the indian Ocean includes beaches and intertidal zones covering 3,000 km2 ( 1,200 sq secret intelligence service ) and 246 larger estuaries. Upwelling areas are modest but crucial. The hypersaline salterns in India covers between 5,000–10,000 km2 ( 1,900–3,900 sq myocardial infarction ) and species adapted for this environment, such as Artemia salina and Dunaliella salina, are crucial to bird life. [ 43 ]
Left : Mangroves ( here in East Nusa Tenggara, Indonesia ) are the only tropical to subtropical forests adapted for a coastal environment. From their origin on the coasts of the Indo-Malaysian region, they have reached a global distribution.
right field : The coelacanth ( here a model from Oxford ), thought extinct for million years, was rediscovered in the twentieth hundred. The indian Ocean species is gloomy whereas the indonesian species is brown. Coral reefs, ocean grass beds, and mangrove forests are the most productive ecosystems of the indian Ocean — coastal areas produce 20 tones per squarely kilometer of pisces. These areas, however, are besides being urbanised with populations often exceeding several thousand people per square kilometer and fishing techniques become more effective and frequently destructive beyond sustainable levels while the increase in sea come on temperature spreads coral bleach. [ 44 ] Mangroves covers 80,984 km2 ( 31,268 sq michigan ) in the indian Ocean area, or about half of the populace ‘s mangrove habitat, of which 42,500 km2 ( 16,400 sq mile ) is located in Indonesia, or 50 % of mangroves in the amerind Ocean. Mangroves originated in the indian Ocean region and have adapted to a wide range of its habitats but it is besides where it suffers its biggest loss of habitat. [ 45 ] In 2016 six new animal species were identified at hydrothermal vents in the Southwest indian Ridge : a “ Hoff ” crab, a “ giant star peltospirid ” snail, a whelk-like snail, a limpet, a scaleworm and a polychaete worm. [ 46 ] The West indian Ocean coelacanth was discovered in the indian Ocean off South Africa in the 1930s and in the late 1990s another species, the indonesian coelacanth, was discovered off Sulawesi Island, Indonesia. Most extant coelacanths have been found in the Comoros. Although both species represent an decree of lobe-finned fishes known from the early Devonian ( 410 mya ) and though extinct 66 mya, they are morphologically distinct from their devonian ancestors. Over millions of years, coelacanths evolved to inhabit different environments — lungs adapted for shallow, brackish waters evolved into gills adapted for bass marine waters. [ 47 ]

biodiversity [edit ]

Of Earth ‘s 36 biodiversity hot spot nine ( or 25 % ) are located on the margins of the indian Ocean .

Madagascar and the islands of the western Indian Ocean (Comoros, Réunion, Mauritius, Rodrigues, the Seychelles, and Socotra), includes 13,000 (11,600 endemic) species of plants; 313 (183) birds; reptiles 381 (367); 164 (97) freshwater fishes; 250 (249) amphibians; and 200 (192) mammals.[48]

The origin of this diversity is debated ; the break-up of Gondwana can explain vicariance older than 100 mya, but the diversity on the younger, smaller islands must have required a Cenozoic dispersion from the rims of the indian Ocean to the islands. A “ invert colonization ”, from islands to continents, apparently occurred more recently ; the chameleons, for case, first diversified on Madagascar and then colonised Africa. several species on the islands of the amerind Ocean are casebook cases of evolutionary processes ; the dung beetles, day gecko, and lemurs are all examples of adaptive radiation. [ citation needed ] Many bones ( 250 bones per squarely meter ) of recently extinct vertebrates have been found in the Mare aux Songes swamp in Mauritius, including bones of the Dodo boo ( Raphus cucullatus ) and Cylindraspis giant tortoise. An analysis of these remains suggests a procedure of aridification began in the southwest indian Ocean began around 4,000 years ago. [ 49 ]

Maputaland-Pondoland-Albany (MPA); 8,100 (1,900 endemic) species of plants; 541 (0) birds; 205 (36) reptiles; 73 (20) freshwater fishes; 73 (11) amphibians; and 197 (3) mammals.[48]

mammal megafauna once far-flung in the MPA was driven to near extinction in the early twentieth century. Some species have been successfully recovered since then — the population of white rhinoceros ( Ceratotherium simum simum ) increased from less than 20 individuals in 1895 to more than 17,000 as of 2013. other species are still subject of fence areas and management programs, including black rhinoceros ( Diceros bicornis minor ), african barbarian chase ( Lycaon pictus ), cheetah ( Acynonix jubatus ), elephant ( Loxodonta africana ), and lion ( Panthera leo ). [ 50 ]

Coastal forests of eastern Africa; 4,000 (1,750 endemic) species of plants; 636 (12) birds; 250 (54) reptiles; 219 (32) freshwater fishes; 95 (10) amphibians; and 236 (7) mammals.[48]

This biodiversity hot spot ( and namesake ecoregion and “ Endemic Bird Area ” ) is a patchwork of small forested areas, often with a unique collection of species within each, located within 200 km ( 120 nautical mile ) from the slide and covering a total area of c. 6,200 km2 ( 2,400 sq mi ). It besides encompasses coastal islands, including Zanzibar and Pemba, and Mafia. [ 51 ]
This area, one of the only two hotspots that are entirely arid, includes the ethiopian Highlands, the East African Rift valley, the Socotra islands, angstrom well as some small islands in the Red Sea and areas on the southerly Arabic Peninsula. Endemic and threatened mammals include the dibatag ( Ammodorcas clarkei ) and Speke ‘s gazelle ( Gazella spekei ) ; the Somali wild american samoa ( Equus africanus somaliensis ) and hamadryas baboon ( Papio hamadryas ). It besides contains many reptiles. [ 52 ] In Somalia, the center of the 1,500,000 km2 ( 580,000 sq nautical mile ) hot spot, the landscape is dominated by Acacia – Commiphora deciduous bushland, but besides includes the Yeheb nut ( Cordeauxia edulus ) and species discovered more recently such as the Somali cyclamen ( Cyclamen somalense ), the only cyclamen outside the Mediterranean. Warsangli house finch ( Carduelis johannis ) is an endemic bird found merely in northern Somalia. An precarious political regimen has resulted in overgrazing which has produced one of the most take down hotspots where alone c. 5 % of the master habitat remains. [ 53 ]

The Western Ghats–Sri Lanka; 5,916 (3,049 endemic) species of plants; 457 (35) birds; 265 (176) reptiles; 191 (139) freshwater fishes; 204 (156) amphibians; and 143 (27) mammals.[48]

Encompassing the west coast of India and Sri Lanka, until c. 10,000 years ago a landbridge connected Sri Lanka to the amerind Subcontinent, hence this region shares a common residential district of species. [ 54 ]

geology [edit ]

Left : The oldest ocean floor of the amerind Ocean formed c. 150 Ma when the indian Subcontinent and Madagascar broke-up from Africa. veracious : The India–Asia collision c. 40 Ma completed the closure of the Tethys Ocean ( grey areas union of India ). Geologically, the indian Ocean is the ocean floor that opened up confederacy of India. As the youngest of the major oceans, [ 59 ] the indian Ocean has active dissemination ridges that are part of the global system of mid-ocean ridges. In the indian Ocean these spreading ridges meet at the Rodrigues Triple Point with the Central Indian Ridge, including the Carlsberg Ridge, separating the african Plate from the amerind Plate ; the Southwest Indian Ridge separating the african Plate from the Antarctic Plate ; and the Southeast Indian Ridge separating the australian plate from the Antarctic Plate. The Central Indian Ridge is intercepted by the Owen Fracture Zone. [ 60 ] Since the late 1990s, however, it has become clear that this traditional definition of the Indo-Australian Plate can not be compensate ; it consists of three plates — the indian Plate, the Capricorn Plate, and australian Plate — separated by diffuse boundary zones. [ 61 ] Since 20 Ma the African Plate is being divided by the East African Rift System into the nubian and Somalia plates. [ 62 ] There are merely two trenches in the amerind Ocean : the 6,000 kilometer ( 3,700 michigan ) -long Java Trench between Java and the Sunda Trench and the 900 kilometer ( 560 nautical mile ) -long Makran Trench south of Iran and Pakistan. [ 60 ] A series of ridges and seamount chains produced by hotspots passing over the indian Ocean. The Réunion hot spot ( active 70–40 million years ago ) connects Réunion and the Mascarene Plateau to the Chagos-Laccadive Ridge and the Deccan Traps in north-western India ; the Kerguelen hot spot ( 100–35 million years ago ) connects the Kerguelen Islands and Kerguelen Plateau to the Ninety East Ridge and the Rajmahal Traps in north-eastern India ; the Marion hot spot ( 100–70 million years ago ) possibly connects Prince Edward Islands to the Eighty Five East Ridge. [ 63 ] These hot spot tracks have been broken by the calm active spread ridges mentioned above. [ 60 ] There are fewer seamounts in the indian Ocean than in the Atlantic and Pacific. These are typically deeper than 3,000 molarity ( 9,800 foot ) and locate north of 55°S and west of 80°E. Most originated at spreading ridges but some are now located in basins far away from these ridges. The ridges of the amerind Ocean form ranges of seamounts, sometimes very long, including the Carlsberg Ridge, Madagascar Ridge, Central Indian Ridge, Southwest Indian Ridge, Chagos-Laccadive Ridge, 85°E Ridge, 90°E Ridge, Southeast Indian Ridge, Broken Ridge, and East Indiaman Ridge. The Agulhas Plateau and Mascarene Plateau are the two major shallow areas. [ 32 ] The open of the indian Ocean began c. 156 Ma when Africa separated from East Gondwana. The indian Subcontinent began to separate from Australia-Antarctica 135–125 Ma and as the Tethys Ocean north of India began to close 118–84 Ma the indian Ocean opened behind it. [ 60 ]

history [edit ]

The indian Ocean, together with the Mediterranean, has connected people since ancient times, whereas the Atlantic and Pacific have had the roles of barriers or mare incognitum. The written history of the amerind Ocean, however, has been Eurocentric and largely subject on the handiness of written sources from the colonial era. This history is much divided into an ancient period followed by an Islamic period ; the subsequent periods are often subdivided into Portuguese, Dutch, and british periods. [ 64 ] A concept of an “ indian Ocean World ” ( IOW ), exchangeable to that of the “ Atlantic World “, exists but emerged a lot more recently and is not well established. The IOW is, however, sometimes referred to as the “ first base ball-shaped economy ” and was based on the monsoon which linked Asia, China, India, and Mesopotamia. It developed independently from the European ball-shaped trade in the Mediterranean and Atlantic and remained largely independent from them until european 19th-century colonial dominance. [ 65 ] The divers history of the indian Ocean is a singular mix of cultures, heathen groups, natural resources, and shipping routes. It grew in importance begin in the 1960s and 1970s and, after the Cold War, it has undergo periods of political instability, most recently with the egress of India and China as regional powers. [ 66 ]

beginning settlements [edit ]

Coastal hypothesis, modern humans spread from Africa along the northern rim of the Indian Ocean. According to the, modern humans spread from Africa along the northern flange of the indian Ocean. Pleistocene fossils of Homo erectus and other pre- H. sapiens hominid fossils, like to H. heidelbergensis in Europe, have been found in India. According to the Toba catastrophe theory, a supereruption c. 74,000 years ago at Lake Toba, Sumatra, covered India with volcanic ashes and wiped out one or more lineages of such antediluvian humans in India and Southeast Asia. [ 67 ] The Out of Africa theory states that Homo sapiens spread from Africa into mainland Eurasia. The more late Southern Dispersal or Coastal hypothesis rather advocates that modern humans spread along the coasts of the Arabic Peninsula and southerly Asia. This hypothesis is supported by mtDNA inquiry which reveals a rapid dispersion event during the Late Pleistocene ( 11,000 years ago ). This coastal dispersion, however, began in East Africa 75,000 years ago and occurred intermittently from estuary to estuary along the northern circumference of the indian Ocean at a pace of 0.7–4.0 km ( 0.43–2.49 mi ) per year. It finally resulted in modern humans migrating from Sunda over Wallacea to Sahul ( Southeast Asia to Australia ). [ 68 ] Since then, waves of migration have resettled people and, distinctly, the indian Ocean littoral had been inhabited hanker before the first civilisations emerged. 5000–6000 years ago six distinct cultural centres had evolved around the amerind Ocean : East Africa, the Middle East, the amerind Subcontinent, South East Asia, the Malay World, and Australia ; each interlinked to its neighbours. [ 69 ] Food globalization began on the amerind Ocean littoral c. 4.000 years ago. Five african crops — sorghum, bone millet, finger millet, black-eyed pea, and hyacinth bean — somehow found their means to Gujarat in India during the Late Harappan ( 2000–1700 BCE ). Gujarati merchants evolved into the beginning explorers of the amerind Ocean as they traded african goods such as ivory, tortoise shells, and slaves. Broomcorn millet found its way from Central Asia to Africa, together with wimp and zebu cattle, although the demand time is disputed. Around 2000 BCE black pepper and sesame, both native to Asia, appear in Egypt, albeit in minor quantities. Around the same clock the black rat and the house mouse emigrate from Asia to Egypt. Banana reached Africa around 3000 years ago. [ 70 ] At least eleven prehistoric tsunamis have struck the amerind Ocean seashore of Indonesia between 7400 and 2900 years ago. Analysing sandpaper beds in caves in the Aceh region, scientists concluded that the intervals between these tsunamis have varied from series of minor tsunami over a hundred to dormant periods of more than 2000 years preceding megathrusts in the Sunda Trench. Although the risk for future tsunami is high, a major megathrust such as the one in 2004 is likely to be followed by a long abeyant period. [ 71 ] A group of scientists have argued that two large-scale impact events have occurred in the amerind Ocean : the Burckle Crater in the southerly indian Ocean in 2800 BCE and the Kanmare and Tabban craters in the Gulf of Carpentaria in northern Australia in 536 CE. Evidences for these impacts, the team argue, are micro-ejecta and Chevron dunes in southerly Madagascar and in the australian gulf. geological evidences suggest the tsunami caused by these impacts reached 205 megabyte ( 673 foot ) above sea level and 45 kilometer ( 28 secret intelligence service ) inland. The affect events must have disrupted homo settlements and possibly even contributed to major climate changes. [ 72 ]

antiquity [edit ]

The history of the amerind Ocean is marked by maritime deal ; cultural and commercial rally probably date back at least seven thousand years. [ 73 ] Human culture spread early on the shores of the indian Ocean and was constantly linked to the cultures of the Mediterranean and the Persian Gulf. Before c. 2000 BCE, however, cultures on its shores were lone loosely tied to each other ; bronze, for case, was developed in Mesopotamia c. 3000 BCE but remained uncommon in Egypt before 1800 BCE. [ 74 ] During this period, mugwump, short-distance oversea communications along its littoral margins evolved into an across-the-board network. The début of this network was not the accomplishment of a centralized or promote culture but of local and regional switch over in the Persian Gulf, the Red Sea, and the Arabian Sea. Sherds of Ubaid ( 2500–500 BCE ) pottery have been found in the western Gulf at Dilmun, contemporary Bahrain ; traces of exchange between this trade center and Mesopotamia. The Sumerians traded grain, pottery, and bitumen ( used for reed boats ) for copper, stone, forest, tin, dates, onions, and pearls. [ 75 ] Coast-bound vessels transported goods between the Indus Valley Civilisation ( 2600–1900 BCE ) in the indian subcontinent ( contemporary Pakistan and Northwest India ) and the Persian Gulf and Egypt. [ 73 ]
The Red Sea, one of the chief deal routes in Antiquity, was explored by Egyptians and Phoenicians during the last two millennium BCE. In the sixth hundred, BCE Greek internet explorer Scylax of Caryanda made a journey to India, working for the Persian king Darius, and his now-lost report put the indian Ocean on the maps of greek geographers. The Greeks began to explore the indian Ocean following the conquests of Alexander the Great, who ordered a circumnavigation of the arabian Peninsula in 323 BCE. During the two centuries that followed the reports of the explorers of Ptolemaic Egypt resulted in the best maps of the region until the Portuguese earned run average many centuries later. The main interest in the area for the Ptolemies was not commercial but military ; they explored Africa to hunt for war elephants. [ 76 ] The Rub ‘ alabama Khali defect isolates the southerly parts of the Arabic Peninsula and the indian Ocean from the Arabic earth. This encouraged the development of nautical trade in the region linking the Red Sea and the Persian Gulf to East Africa and India. The monsoon ( from mawsim, the Arabic word for temper ), however, was used by sailors long before being “ discovered ” by Hippalus in the first hundred. indian wood have been found in sumerian cities, there is evidence of Akkad coastal trade in the region, and contacts between India and the Red Sea dates back to 2300 B.C. The archipelagoes of the central indian Ocean, the Laccadive and Maldive islands, were credibly populated during the second hundred B.C. from the indian mainland. They appear in written history in the account of merchant Sulaiman al-Tajir in the ninth century but the punic reefs of the islands were most probably cursed by the sailors of Aden long before the islands were even settled. [ 77 ]
Periplus of the Erythraean Sea, an alexandrian guide to the worldly concern beyond the Red Sea — including Africa and India — from the first century CE, not entirely gives insights into trade in the region but besides shows that Roman and Greek sailors had already gained cognition about the monsoon winds. [ 73 ] The contemporaneous settlement of Madagascar by austronesian sailors shows that the littoral margins of the indian Ocean were being both well-populated and regularly traversed at least by this time. Albeit the monsoon must have been common cognition in the indian Ocean for centuries. [ 73 ] The indian Ocean ‘s relatively calm waters opened the areas bordering it to trade earlier than the Atlantic or Pacific oceans. The powerful monsoons besides meant ships could easily sail west early in the season, then wait a few months and reelect eastwards. This allow ancient indonesian peoples to cross the indian Ocean to settle in Madagascar around 1 CE. [ 78 ] In the 2nd or first hundred BCE, Eudoxus of Cyzicus was the inaugural Greek to cross the indian Ocean. The credibly fabricated bluejacket Hippalus is said to have learnt the directly road from Arabia to India around this time. [ 79 ] During the 1st and 2nd centuries AD intensifier trade wind relations developed between Roman Egypt and the Tamil kingdoms of the Cheras, Cholas and Pandyas in Southern India. Like the indonesian people above, the western sailors used the monsoon to cross the ocean. The nameless generator of the Periplus of the Erythraean Sea describes this route, a well as the commodities that were traded along versatile commercial ports on the coasts of the Horn of Africa and India circa 1 CE. Among these trade settlements were Mosylon and Opone on the Red Sea littoral. [ 9 ]

Age of Discovery [edit ]

Preferred sailing routes across the amerind Ocean Unlike the Pacific Ocean where the civilization of the Polynesians reached most of the far-flung islands and atolls and populated them, about all the islands, archipelagos and atolls of the indian Ocean were uninhabited until colonial times. Although there were numerous ancient civilizations in the coastal states of Asia and parts of Africa, the Maldives were the merely island group in the Central Indian Ocean region where an ancient culture flourished. [ 80 ] Maldivians, on their annual trade slip, took their oceangoing trade ships to Sri Lanka quite than mainland India, which is much closer, because their ships were dependant of the indian Monsoon Current. [ 81 ] Arabic missionaries and merchants began to spread Islam along the western shores of the indian Ocean from the eighth century, if not earlier. A Swahili stone mosque dating to the 8th–15th centuries has been found in Shanga, Kenya. Trade across the indian Ocean gradually introduced Arabic script and rice as a staple in Eastern Africa. [ 82 ] Muslim merchants traded an calculate 1000 african slaves per annum between 800 and 1700, a number that grew to c. 4000 during the eighteenth century, and 3700 during the time period 1800–1870. Slave deal besides occurred in the eastern indian Ocean before the dutch settled there around 1600 but the book of this deal is nameless. [ 83 ] From 1405 to 1433 admiral Zheng He said to have led large fleets of the Ming Dynasty on several treasure voyages through the indian Ocean, ultimately reaching the coastal countries of East Africa. [ 84 ]
The Portuguese navigator Vasco district attorney Gama rounded the Cape of Good Hope during his first voyage in 1497 and became the first base european to sail to India. The swahili people he encountered along the African east slide lived in a series of cities and had established trade routes to India and to China. Among them, the Portuguese kidnapped most of their pilots in coastal raids and onboard ships. A few of the pilots, however, were gifts by local Swahili rulers, including the bluejacket from Gujarat, a giving by a Malindi rule in Kenya, who helped the Portuguese to reach India. In expeditions after 1500, the Portuguese attacked and colonize cities along the African slide. [ 85 ] european slave deal in the amerind Ocean began when Portugal established Estado district attorney Índia in the early sixteenth century. From then until the 1830s, c. 200 slaves were exported from Mozambique annually and like figures has been estimated for slaves brought from Asia to the Philippines during the Iberian Union ( 1580–1640 ). [ 83 ] The Ottoman Empire began its expansion into the indian Ocean in 1517 with the conquest of Egypt under Sultan Selim I. Although the Ottomans shared the lapp religion as the trade communities in the indian Ocean the region was unexplored by them. Maps that included the indian Ocean had been produced by Muslim geographers centuries before the Ottoman conquests ; Muslim scholars, such as Ibn Battuta in the fourteenth Century, had visited most parts of the known universe ; contemporarily with Vasco district attorney Gama, Arab sailing master Ahmad ibn Mājid had compiled a usher to navigation in the indian Ocean ; the Ottomans, however, began their own parallel era of discovery which rivalled the european expansion. [ 86 ] The establishment of the Dutch East India Company in the early seventeenth hundred moderate to a immediate increase in the volume of the slave deal in the area ; there were possibly up to 500,000 slaves in assorted Dutch colonies during the 17th and 18th centuries in the indian Ocean. For model, some 4000 african slaves were used to build the Colombo fortress in Dutch Ceylon. Bali and neighbouring islands supplied regional networks with c. 100,000–150,000 slaves 1620–1830. indian and chinese slave traders supplied Dutch Indonesia with possibly 250,000 slaves during the 17th and 18th centuries. [ 83 ] The East India Company ( EIC ) was established during the lapp period and in 1622 one of its ships carried slaves from the Coromandel Coast to Dutch East Indies. The EIC by and large traded in african slaves but besides some asian slaves purchased from indian, indonesian and chinese slave traders. The french established colonies on the islands of Réunion and Mauritius in 1721 ; by 1735 some 7,200 slaves populated the Mascarene Islands, a act which had reached 133,000 in 1807. The british captured the islands in 1810, however, and because the british had prohibited the slave deal in 1807 a arrangement of clandestine slave trade developed to bring slaves to french planters on the islands ; in all 336,000–388,000 slaves were exported to the Mascarene Islands from 1670 until 1848. [ 83 ] In all, european traders exported 567,900–733,200 slaves within the indian Ocean between 1500 and 1850 and about that same come were exported from the indian Ocean to the Americas during the like period. Slave deal in the indian Ocean was, however, identical limited compared to c. 12,000,000 slaves exported across the Atlantic. [ 83 ]

Modern era [edit ]

Malé ‘s population has increased from 20,000 people in 1987 to more than 220,000 people in 2020. scientifically, the indian Ocean remained ailing explored before the International indian Ocean Expedition in the early 1960s. however, the Challenger expedition 1872–1876 only reported from south of the arctic presence. The Valdivia dispatch 1898–1899 made abstruse samples in the indian Ocean. In the 1930s, the John Murray Expedition chiefly studied shallow-water habitats. The swedish Deep Sea Expedition 1947–1948 besides sampled the indian Ocean on its ball-shaped go and the Danish Galathea sampled deep-water animal from Sri Lanka to South Africa on its second base excursion 1950–1952. The soviet inquiry vessel Vityaz besides did research in the indian Ocean. [ 1 ] The Suez Canal opened in 1869 when the Industrial Revolution dramatically changed global transportation – the sailing ship declined in importance as did the importance of european barter in privilege of trade in East Asia and Australia. [ 87 ] The construction of the canal introduced many non-indigenous species into the Mediterranean. For case, the goldband goatfish ( Upeneus moluccensis ) has replaced the red mullet ( Mullus barbatus ) ; since the 1980s huge swarms of scyphozoan jellyfish ( Rhopilema nomadica ) have affected tourism and fisheries along the Levantian seashore and clogged power and desalination plants. Plans announced in 2014 to build a fresh, much larger Suez Canal latitude to the 19th-century duct will most likely boost the economy in the region but besides cause ecological damage in a much wider sphere. [ 88 ]
An nameless Chagossian on Diego Garcia in 1971 shortly before the british expelled the islanders when the island became a U.S. military base. The man spoke a French-based creole linguistic process and his ancestors were most probably bring to the uninhabited island as slaves in the nineteenth century. Throughout the colonial era, islands such as Mauritius were crucial ship nodes for the Dutch, French, and British. Mauritius, an dwell island, became populated by slaves from Africa and indenture labor from India. The end of World War II marked the end of the colonial earned run average. The british left Mauritius in 1974 and with 70 % of the population of indian lineage, Mauritius became a close ally of India. In the 1980s, during the Cold War, the confederacy african government acted to destabilise several island nations in the indian Ocean, including the Seychelles, Comoros, and Madagascar. India intervened in Mauritius to prevent a coup d’etat d’état, backed up by the United States who feared the Soviet Union could gain access to Port Louis and threaten the U.S. base on Diego Garcia. [ 89 ] Iranrud is an unfulfilled plan by Iran and the Soviet Union to build a duct between the Caspian Sea and the Persian Gulf. Testimonies from the colonial earned run average are stories of african slaves, indian apprenticed labourers, and white settlers. But, while there was a clear up racial line between free men and slaves in the Atlantic World, this depiction is less clear-cut in the indian Ocean — there were indian slaves and settlers american samoa well as black indenture labourers. There were besides a string of prison camps across the indian Ocean, such as cellular Jail in the Andamans, in which prisoners, exiles, POWs, forced labourers, merchants, and people of different faiths were forcefully unite. On the islands of the amerind Ocean, therefore, a drift of creolisation emerged. [ 90 ] On 26 December 2004 fourteen countries around the indian Ocean were hit by a wave of tsunami caused by the 2004 indian Ocean earthquake. The waves radiated across the ocean at speeds exceeding 500 kilometers per hour ( 310 miles per hour ), reached up to 20 thousand ( 66 foot ) in height, and resulted in an calculate 236,000 deaths. [ 91 ] In the late 2000s, the ocean evolved into a hub of pirate activeness. By 2013, attacks off the Horn region ‘s coast had steadily declined due to active private security and international united states navy patrols, particularly by the amerind Navy. [ 92 ] malaysian Airlines Flight 370, a Boeing 777 airliner with 239 persons on board, disappeared on 8 March 2014 and is alleged to have crashed into the southern indian Ocean about 2,500 km ( 1,600 nautical mile ) from the slide of southwest western Australia. Despite an extensive search, the whereabouts of the remains of the aircraft is stranger. [ 93 ] The Sentinelese people of North Sentinel Island, which lies near South Andaman Island in the Bay of Bengal, have been called by experts the most detached people in the worldly concern. [ 94 ] The sovereignty of the Chagos Archipelago in the indian Ocean is disputed between the United Kingdom and Mauritius. [ 95 ] In February 2019, the International Court of Justice in The Hague issued an advisory opinion stating that the UK must transfer the Chagos Archipelago to Mauritius. [ 96 ]

Trade [edit ]

The sea lanes in the amerind Ocean are considered among the most strategically important in the global with more than 80 percentage of the world ‘s seaborne barter in oil transits through the indian Ocean and its vital chokepoints, with 40 percentage fall through the Strait of Hormuz, 35 percentage through the Strait of Malacca and 8 percentage through the Bab el-Mandab Strait. [ 97 ] The indian Ocean provides major ocean routes connecting the Middle East, Africa, and East Asia with Europe and the Americas. It carries a particularly heavy traffic of petroleum and petroleum products from the petroleum fields of the Persian Gulf and Indonesia. Large reserves of hydrocarbons are being tapped in the offshore areas of Saudi Arabia, Iran, India, and Western Australia. An calculate 40 % of the universe ‘s offshore oil production comes from the indian Ocean. [ 3 ] Beach sands rich in heavy minerals, and offshore placer deposits are actively exploited by bordering countries, particularly India, Pakistan, South Africa, Indonesia, Sri Lanka, and Thailand .
Mombasa Port on Kenya’s Indian Ocean coast In particular, the maritime depart of the Silk Road leads through the indian Ocean on which a big part of the global container trade is carried out. The Silk Road runs with its connections from the chinese coast and its large container ports to the south via Hanoi to Jakarta, Singapore and Kuala Lumpur through the Strait of Malacca via the Sri Lankan Colombo opposite the southerly lean of India via Malé, the das kapital of the Maldives, to the East African Mombasa, from there to Djibouti, then through the Red Sea over the Suez Canal into the Mediterranean, there via Haifa, Istanbul and Athens to the Upper Adriatic to the northerly italian junction of Trieste with its international detached port and its rail connections to Central and Eastern Europe. [ 98 ] [ 99 ] [ 100 ] [ 101 ] The Silk Road has become internationally important again on the one hired hand through european consolidation, the end of the Cold War and release world trade wind and on the other hand through chinese initiatives. chinese companies have made investments in respective indian Ocean ports, including Gwadar, Hambantota, Colombo and Sonadia. This has sparked a debate about the strategic implications of these investments. [ 102 ] There are besides taiwanese investments and associate efforts to intensify trade in East Africa and in european ports such as Piraeus and Trieste. [ 103 ] [ 104 ] [ 105 ]

See besides [edit ]

References [edit ]

Notes [edit ]

Sources [edit ]

farther reading [edit ]

Bahl, Christopher D. “Transoceanic Arabic historiography: sharing the past of the sixteenth-century western Indian Ocean.” Journal of Global History 15.2 (2020): 203–223.
Palat, Ravi. The Making of an Indian Ocean World-Economy, 1250–1650: Princes, Paddy fields, and Bazaars (2015)
Pearson, Michael. Trade, Circulation, and Flow in the Indian Ocean World (2015_0(Palgrave Series in Indian Ocean World Studies)
Schnepel, Burkhard and Edward A. Alpers, eds. Connectivity in Motion: Island Hubs in the Indian Ocean World (2017).
Schottenhammer, Angela, ed. Early Global Interconnectivity across the Indian Ocean World, Volume I: Commercial Structures and Exchanges (2019)
Schottenhammer, Angela, ed. Early Global Interconnectivity across the Indian Ocean World, Volume II: Exchange of Ideas, Religions, and Technologies (2019)
Serels, Steven, ed. The Impoverishment of the African Red Sea Littoral, 1640–1945 (2018)

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Indian Ocean – Wikipedia