പേജുകള്‍‌

Bay of Bengal


The Bay of Bengal, the largest bay in the world,  forms the northeastern part of the Indian Ocean. Roughly triangular in shape, it is bordered mostly by India and Sri Lanka to the west, Bangladesh to the north, and Burma (Myanmar) and the Andaman and Nicobar Islands to the east.
The Bay of Bengal occupies an area of 2,172,000 km². A number of large rivers – the Ganges and its distributaries such as Padma and Hooghly,Brahmaputra and its distributaries such as JamunaMeghnaIrrawaddy RiverGodavariMahanadiKrishna and Kaveri – flow into the Bay of Bengal. Among the important ports are CuddaloreEnnoreChennaiKaraikalPondicherryTuticorinKakinadaMachilipatnamVisakhapatnam,GangavaramKrishnapatnamParadipKolkataMonglaChittagong and Yangon.

Extent
On the East.
 A line running from Cape Negrais (16°03'N) in Burma through the larger islands of the Andaman group, in such a way that all the narrow waters between the islands lie to the Eastward of the line and are excluded from the Bay of Bengal, as far as a point in Little AndamanIsland in latitude 10°48'N, longitude 92°24'E and thence along the Southwest limit of the Burma Sea [A line running from Oedjong Raja in Sumatra to Poeloe Bras (Breuëh) and on through the Western Islands of the Nicobar Group to Sandy Point in Little Andaman Island, in such a way that all the narrow waters appertain to the Burma Sea].

The International Hydrographic Organization defines the limits of the Bay of Bengal as follows: 
 
On the South. Adam's Bridge (between India and Ceylon [Sri Lanka]) and from the Southern extreme of Dondra Head (South point of Ceylon) to the North point of Poeloe Bras 
Rivers                                                                                                                                                                          Many major rivers of the Indian subcontinent flow west to east before draining into Bay of Bengal. The Ganges is the northernmost of them. Its main channel enters and flows through Bangladesh, where it is called Padma River, before joining Meghna River. However, Brahmaputra River flows from east to west in Assam before turning south and entering Bangladesh where it is called Jamuna River. Jamuna joins Padma and then Padma joins Meghna River that finally drains into Bay of Bengal. The Sundarbans mangrove forest is formed at the delta of the Ganges, Brahmaputra and Meghna rivers and lies partly in West Bengal and partly in Bangladesh. Brahmaputra at 2,948 km (1,832 mi) is the 28th longest River in the world. It originates in Tibet.Hooghly River, another channel of the Ganga that flows through Calcutta drains into Bay of Bengal in India itself.                                                                                       Etymology
The Bay of Bengal appears as Sinus Gangeticus or Gangeticus Sinus, meaning "Gulf of the Ganges", in ancient maps. In the 10th century the explosion of Indianized kingdoms, led by the Chola Empire, resulted in the Bay of Bengal being known as the Chola Lake. It later came to be known asBay of Bengal in after the region of Bengal.
Further south of Bengal, Mahanadi RiverGodavari RiverKrishna River and Kaveri River (earlier spelt as Cauvery) are the major rivers that flow from west to east in Indian subcontinent and drain into Bay of Bengal. Many small rivers also drain directly into Bay of Bengal; the shortest of them is Cooum River at 64 km (40 mi).
The Irrawaddy River also spelt as Ayeyarwady of Burma flows into Andaman Sea of Bay of Bengal and once had thick mangrove forest of its own.
Sea portsIslands
The islands in the bay are very numerous, including the Andaman IslandsNicobar and Mergui groups of India. The group of islands, Cheduba and others, in the north-east, off the Burmese coast, are remarkable for a chain of mud volcanoes, which are occasionally active. Great Andaman is the main archipelago or island group of the Andaman Islands, whereas Ritchie's Archipelago consists of smaller islands. Only 37 of the 572 islands and islets of the Andaman and Nicobar Islands are inhabited, or 6.5%.
BeachesOceanography
The Bay of Bengal is a salt water sea and is a part of the Indian Ocean.


Plate tectonics
Marine geology
The lithosphere of the earth is broken up into what are called tectonic plates. Underneath the Bay of Bengal is the Indian Plate which is part of the great Indo-Australian Plate and is slowly moving north east. This plate meets the Burma Microplate at the Sunda Trench. TheNicobar Islands, and the Andaman Islands are part of the Burma Microplate. The India Plate subducts beneath the Burma Plate at the Sunda Trench or Java Trench. Here, the pressure of the two plates on each other increase pressure and temperature resulting in the formation of volcanoes such as thevolcanoes in Myanmar, and a volcanic arc called the Sunda ArcSumatra-Andaman earthquake and Asian Tsunami was a result of the pressure at this zone causing a submarine earthquake which then resulted in a huge Tsunami.

[edit]

A zone 50 m wide extending from the island of Ceylon and the Coromandel coast to the head of the bay, and thence southwards through a strip embracing the Andaman and Nicobar islands, is bounded by the 100 fathom line of sea bottom; some 50 m. beyond this lies the 500-fathom limit. Opposite the mouth of the Ganges, however, the intervals between these depths are very much extended by deltaic influence.
Swatch of No Ground is a 14 km-wide deep sea canyon of the Bay of Bengal. The deepest recorded area of this valley is about 1340 m. The submarine canyon is part of the Bengal Fan, the largest submarine fan in the world.
Marine biology, flora and fauna
Kerilia jerdonii
 is a sea snake of the Bay of Bengal. Glory of Bengal Cone (Conus bengalensis) is just one of the seashells which can be photographed along beaches of the Bay of Bengal.
  An endangered species, the Olive Ridley sea turtle can survive because of the nesting grounds made available at the Gahirmatha Marine Wildlife Sanctuary, Gahirmatha BeachOrissaIndiaMarlinbarracudaskipjack tuna, (Katsuwonus pelamis), yellowfin tuna,Indo-Pacific humpbacked dolphin (Sousa chinensis), and Bryde's whale (Balaenoptera edeni) are a few of the marine animals. Bay of Bengal Hogfish (Bodianus neilli) is a type of Wrass which live in turbid lagoon reefs or shallow coastal reefs. Schools of dolphins can be seen, whether they are thebottle nose dolphin (Tursiops truncatus), Pantropical spotted dolphin (Stenella attenuata) or the spinner dolphin (Stenella longirostris) . Tuna anddolphins are usually residing in the same waters. In shallower and warmer coastal waters the Irrawaddy Dolphins (Orcaella brevirostris) can be found.
The Bay of Bengal is full of biological diversity, diverging amongst coral reefsestuaries, fish spawning and nursery areas, and mangroves. The Bay of Bengal is one of the World's 64 largest marine ecosystems.
The Great Nicobar Biosphere Reserve provides sanctuary to many animals some of which include the saltwater crocodile (Crocodylus porosus), giantLeatherback Sea Turtle (Dermochelys coriacea), and Malayan box turtle (Cuora amboinensis kamaroma) to name a few.
Another endangered species Royal Bengal Tiger is supported by Sundarbans a large estuarine delta that holds a mangrove area in the Ganges River Delta.
Chemical oceanography
Coastal regions bordering the Bay of Bengal are rich in minerals. Sri Lanka, Serendib, or Ratna – Dweepa which means Gem Island. Amethystberylrubysapphiretopaz, and garnet are just some of the gems of Sri Lanka. Garnet and other precious gems are also found in abundance in the Indian states of Orissa and Andhra Pradesh.
Physical oceanography - climate of the Bay of Bengal
From January to October, the current is northward flowing, and the clockwise circulation pattern is called the "East Indian Current." The Bay of Bengal monsoon moves in a northwest direction striking the Nicobar Islands, and the Andaman Islands first end of May, then the North Eastern Coast of India by end of June.
The remainder of the year, the counterclockwise current is southwestward flowing, and the circulation pattern is called the East Indian Winter Jet. September and December see very active weather, season varsha (or monsoon), in the Bay of Bengal producing severe Cyclones which affect Eastern India. Several efforts have been initiated to cope with Storm surge.
Tropical storms and cyclones 2012, Cyclone Nilam
A tropical storm with rotating winds blowing at speeds of 74 miles (119 kilometres) per hour are called cyclones when they originate over the Bay of Bengal; they are hurricanes in the Atlantic. Between 100,000 and 500,000 residents of Bangladesh were killed because of the 1970 Bhola cyclone.
  • 2011, Very Severe Cyclonic Storm Thane
  • 2010, Very Severe Cyclonic Storm Giri
  • 2008, Very Severe Cyclonic Storm Nargis
  • 2007, Very Severe Cyclonic Storm Sidr
  • 2006, Very Severe Cyclonic Storm Mala
  • 1999, Super Cyclonic Storm 05B
  • 1991, Super Cyclonic Storm 02B
  • 1989, November Typhoon Gay
  • 1985, May Tropical Storm One (1B)
  • 1982, April Cyclone One (1B)
  • 1982, May Tropical Storm Two (2B)
  • 1982, October Tropical Storm Three (3B)
  • 1981, December Cyclone Three (3B)
  • 1980, October Tropical Storm One (1B)
  • 1980, December Unknown Storm Four (4B)
  • 1980, December Tropical Storm Five (5B)
  • 1977, Andhra Pradesh Cyclone (6B)
  • 1971, Cyclone Orissa
  • 1970, November Bhola cyclone
  • The Calcutta cyclone of 1864: caused a storm surge of 40 feet. Barometer 28.025 inches of mercury. 50,000 direct deaths and 30,000 from disease. 
  • The Backergunge cyclone of 1876: 10 to 30 or 40 feet storm surge. 100,000 direct deaths and 100,000 indirect from disease. 
  • The False Point cyclone of 1885: 22 feet of storm surge. Barometer 27.135 inches of mercury. 
Historic sites
  • The remains of Sri Vaisakheswara Swamy temple lies under the Bay of Bengal. Spokespersons from Andhra University Centre for Marine Archaeology say the temple may be located opposite the Coastal Battery.
  • Seven Pagodas of Mahabalipuram is the name for Mahabalipuram. Mahabalipuram's Shore Temple was constructed in the 8th century AD and myth has it that six other temples were also built here.
  • Another historic site which has been preserved is Vivekanandar Illam. It was constructed in 1842 by the Ice King Frederic Tudor to store and market ice year round. In 1897, Swami Vivekananda famous lectures were recorded here at Castle Kernan. The site is an exhibition devoted to Swami Vivekananda and his legacy.
  • Konark is the home of the Sun Temple or Black Pagoda. This Brahman sanctuary was built of black granite mid 1200 AD and has been declared a World Heritage Site.
  • Ramanathaswami Temple located at Dhanushkodi, where the Bay of Bengal and the Indian Ocean come together.
  • German Rosat spacecraft re-entered over Bay of Bengal, the tumbling German satellite Rosat re-entered the Earth's atmosphere over the Bay of Bengal, the German space agency (DLR) has confirmed. ROSAT
Economy
BIMSTEC
 Bay of Bengal Initiative for MultiSectoral Technical and Economic Cooperation (BIMSTEC) supports free trade internationally around the Bay of Bengal between BangladeshBhutanIndiaMyanmarNepalSri Lanka, and Thailand.
One of the first trading ventures along the Bay of Bengal was The Company of Merchants of London Trading into the East Indies more commonly referred to as British East India CompanyGopalpur was one of their main trading centers. Other trading companies along the Bay of Bengal shorelines were English East India Company and French East India Company.
The Sethusamudram Shipping Canal Project is a new venture proposed which would create a channel for a shipping route to link the Gulf of Mannar with the Bay of Bengal. This would connect India east to west without the necessity of going around Sri Lanka.
Thoni and catamaran fishing boats of fishing villages thrive along the Bay of Bengal shorelines. Fishermen can catch between 26 and 44 species of marine fish. In one year, the average catch is 2 million tons of fish from the Bay of Bengal alone.
Strategic importance of Bay of Bengal
The Bay of Bengal is centrally located in the region from the Middle East to the Philippine Sea. Even from aviations strategic aerial position it lies at the centre. It lies at dead center of two huge economic blocks, the SAARC and ASEAN. China's southern landlocked region in the north, and major sea ports of Bangladesh and India. Both rising economically, though with chaotic democracies. Bangladesh, China and India has forged naval cooperation agreements with Malaysia, Thailand and Indonesia to increase its cooperation in checking terrorism in the high seas.

The Bay of Bengal is strategically crucial for India since it is a natural extension of its sphere of influence. Secondly because of the presence of outlying islands, namely Andaman islands and Nicobar islands and most importantly several major ports such as KolkataChennaiVizag, andTuticorin along its coast with the Bay of Bengal.
China has recently made some efforts to project influence into the region through tie-ups with Myanmar and Bangladesh. The United States held several major exercises with BangladeshIndiaMalaysiaSingapore and Thailand. The largest ever wargame in Bay of Bengal, known as Malabar 2007, was held in 2007 and naval warships from US, Singapore, Japan and Australia took part in it. India, was also a participant. Large deposits of natural gas also incited a serious up for grabs urgency by India. Disputes over rights of some oil and gas blocks have caused brief diplomatic spats between Myanmar and India with Bangladesh.
The disputed maritime boundary between Bangladesh and Myanmar has twice resulted in military tensions, in 2008 and 2009. Bangladesh is currently pursuing a settlement with Myanmar and India to the boundary dispute through the International Tribunal on the Law of the Sea.
Environmental hazards


Pollution
The Asian brown cloud, a layer of air pollution that covers much of South Asia and the Indian Ocean every year between January and March, and possibly also during earlier and later months, hangs over the Bay of Bengal. It is considered to be a combination of vehicle exhaust, smoke from cooking fires, and industrial discharges.
History
Northern Circars
 occupied the western coast of the Bay of Bengal and is now considered to be India's Madras state. Chola dynasty (9th century to 12th century) when ruled by Rajaraja Chola I occupied the western coastline of the Bay of Bengal circa AD 1014, The Bay of Bengal was also called as the Chola Lake.The Kakatiya dynasty reached the western coastline of the Bay of Bengal between the Godavari and the Krishna rivers. Kushanas about the middle of the 1st century AD invaded northern India perhaps extending as far as the Bay of Bengal. Chandragupta Maurya extended the Maurya Dynasty across Northern India to the Bay of Bengal. Hajipur was a stronghold of Portuguese Pirates. In the 16th century the Portuguese built trading posts in the North of the Bay of Bengal at Chittagong (Porto Grande) and Satgaon (Porto Pequeno).


British penal colony
Cellular Jail or "Black Waters" built in 1896 on Ross Island, a part of the Andaman Island Chain. As early as 1858 this island was used as a British penal colony for political prisoners facing life imprisonment.

Marine archaeology
Maritime archaeology or marine archaeology is the study of material remains of ancient peoples. A specialized branch, Archaeology of shipwrecksstudies the salvaged artifacts of ancient ships. Stone anchors, amphorae shards, elephant tusks, hippopotamus teeth, ceramic pottery, a rare wood mast and lead ingots are examples which may survive the test of time for archaeologists to study and place the salvaged findings into a time line of history. Coral reefs, tsunamis, cyclones, mangrove swamps, battles and a criss cross of sea routes in a high trading area combined with pirating have all contributed to shipwrecks in the Bay of Bengal.