BERING SEA

Speciality

The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves.The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves.The Bering Sea is separated from the Gulf of Alaska by the Alaska Peninsula. It covers over 2,000,000 square kilometres (770,000 sq mi) bordered on the east and northeast by Alaska, on the west by Russia's Far East and Kamchatka Peninsula, on the south by the Alaska Peninsula and the Aleutian Islands and on the far north by the Bering Strait, which connects the Bering Sea to the Arctic Ocean's Chukchi Sea. Bristol Bay is the portion of the Bering Sea which separates the Alaska Peninsula from mainland Alaska. The Bering Sea is named for Vitus Bering, a Danish navigator in Russian service, who in 1728 was the first European to systematically explore it, sailing from the Pacific Ocean northward to the Arctic Ocean

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History

Most scientists believe that during the most recent ice age, sea level was low enough to allow humans and other animals to migrate on foot from Asia to North America across what is now the Bering Strait. This is commonly referred to as the "Bering land bridge" and is believed by some—though not all— to be the first point of entry of humans into the Americas.There is a small portion of the Kula Plate in the Bering Sea. The Kula Plate is an ancient tectonic plate that used to subduct under Alaska during the Triassic period.

Geography

On the South. A line running from Kabuch Point (54°48′N 163°21′W) in the Alaskan Peninsula, through the Aleutian Islands to the South extremes of the Komandorski Islands and on to Cape Kamchatka in such a way that all the narrow waters between Alaska and Kamchatka are included in the Bering Sea.The Bering Sea shelf break is the dominant driver of primary productivity in the Bering Sea. This zone, where the shallower continental shelf drops off into the North Aleutians Basin is also known as the “Greenbelt”. Nutrient upwelling from the cold waters of the Aleutian basin flowing up the slope and mixing with shallower waters of the shelf provide for constant production of phytoplankto.

Ecosystem

The second driver of productivity in the Bering Sea is seasonal sea ice that, in part, triggers the spring phytoplankton bloom. Seasonal melting of sea ice causes an influx of lower salinity water into the middle and other shelf areas, causing stratification and hydrographic effects which influence productivity. In addition to the hydrographic and productivity influence of melting sea ice, the ice itself also provides an attachment substrate for the growth of algae as well as interstitial ice algae.

LRISH SEA

Speciality

The Irish Sea separates the islands of Ireland and Great Britain. It is connected to the Celtic Sea in the south by St George's Channel, and to the Atlantic Ocean in the north by the North Channel.The Irish Sea (Irish: Muir Éireann, Manx: Y Keayn Yernagh, Scots: Erse Sea, Scottish Gaelic: Muir Èireann, Ulster-Scots: Airish Sea, Welsh: Môr Iwerddon) separates the islands of Ireland and Great Britain. It is connected to the Celtic Sea in the south by St George's Channel, and to the Atlantic Ocean in the north by the North Channel. Anglesey is the largest island within the Irish Sea, followed by the Isle of Man. The sea is occasionally, but rarely, referred to as the Manx Sea (Irish: Muir Meann Manx: Mooir Vannin, Scottish Gaelic: Muir Mhanainn).The sea is of significant economic importance to regional trade, shipping and transport, fishing, and power generation in the form of wind power and nuclear plants. Annual traffic between Great Britain and Ireland amounts to over 12 million passengers and 17 million tonnes of traded goods.

Geography

The most accessible and possibly the greatest wildlife resource of the Irish Sea lies in its estuaries: particularly the Dee Estuary, the Mersey Estuary, the Ribble Estuary, Morecambe Bay, the Solway Firth, Loch Ryan, the Firth of Clyde, Belfast Lough, Strangford Lough, Carlingford Lough, Dundalk Bay, Dublin Bay and Wexford Harbour. However, a lot of wildlife also depends on the cliffs, salt marshes and sand dunes of the adjoining shores, the seabed and the open sea itself.The information on the invertebrates of the seabed of the Irish Sea is rather patchy because it is difficult to survey such a large area, where underwater visibility is often poor and information often depends upon looking at material brought up from the seabed in mechanical grabs. However, the groupings of animals present depend to a large extent on whether the seabed is composed of rock, boulders, gravel, sand, mud or even peat. In the soft sediments seven types of community have been

Radioactivity

The Irish Sea has been described by Greenpeace as the most radioactively contaminated sea in the world with some "eight million litres of nuclear waste" discharged into it each day from Sellafield reprocessing plants, contaminating seawater, sediments and marine life.Low-level radioactive waste has been discharged into the Irish Sea as part of operations at Sellafield since 1952. The rate of discharge began to accelerate in the mid- to late 1960s, reaching a peak in the 1970s and generally declining significantly since then. As an example of this profile, discharges of plutonium (specifically 241Pu) peaked in 1973 at 2,755TBq falling to 8.1 TBq by 2004. Improvements in the treatment of waste in 1985 and 1994 resulted in further reductions in radioactive waste discharge although the subsequent processing of a backlog resulted in increased discharges of certain types of radioactive waste. Discharges of technetium in particular rose from 6.1 TBq in 1993 to a peak of 192TBq in 1995 before dropping back to 14TBq in 2004. In total 22PBq of 241Pu was discharged over the period 1952 to 1998. Current rates of discharge for many radionuclides are at least 100 times lower than they were in the 1970s.

ADRIATIC SEA

speciality

The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula and the Apennine Mountains from the Dinaric Alps and adjacent ranges.The Adriatic Sea /ˌeɪdriˈætɨk/ (Albanian: Deti Adriatik; Croatian: Jadransko more; Istro-Romanian: marea Adriatică; Italian: mare Adriatico; Slovene: Jadransko morje) is a body of water separating the Italian Peninsula from the Balkan peninsula and the Apennine Mountains from the Dinaric Alps and adjacent ranges. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to the northwest and the Po Valley. The countries with coasts on the Adriatic are Italy, Croatia, Albania, Montenegro, Bosnia-Herzegovina, and Slovenia. The Adriatic contains over 1,300 islands, mostly located along its eastern, Croatian, coast. It is divided into three basins, the northern being the shallowest and the southern being the deepest, with a maximum depth of 1,233 metres (4,045 ft). The Otranto Sill, an underwater ridge, is located at the border between the Adriatic and Ionian Seas. The prevailing currents flow counterclockwise from the Strait of Otranto, along the eastern coast and back to the strait along the western (Italian) coast. Tidal movements in the Adriatic are slight, although larger amplitudes are known to occur occasionally. The Adriatic's salinity is lower than the Mediterranean's because the Adriatic collects a third of the fresh water flowing into the Mediterranean, acting as a dilution basin. The surface water temperatures generally range from 24 °C (75 °F) in summer to 12 °C (54 °F) in winter, significantly moderating the Adriatic Basin's climate.

Geography

The Adriatic Sea is a semi-enclosed sea bordered in the southwest by the Apennine or Italian Peninsula, in the northwest by the Italian regions of Veneto and Friuli-Venezia Giulia, and in the northeast by Slovenia, Croatia, Bosnia-Herzegovina, Montenegro, and Albania—the Balkan peninsula. In the southeast, the Adriatic Sea connects to the Ionian Sea at the 72-kilometre (45 mi) wide Strait of Otranto. The International Hydrographic Organization (IHO) defines the boundary between the Adriatic and the Ionian seas as a line running from the Butrinto River's mouth (latitude 39°44'N) in Albania to the Karagol Cape in Corfu, through this island to the Kephali Cape (these two capes are in latitude 39°45'N), and on to the Santa Maria di Leuca Cape (latitude 39°48'N) It extends 800 kilometres (500 mi) from the northwest to the southeast and is 200 kilometres (120 mi) wide. It covers 138,600 square kilometres (53,500 sq mi) and has a volume of 35,000 cubic kilometres (8,400 cu mi). The Adriatic extends northwest from 40° to 45°47' north, representing the Mediterranean's northernmost portion.

Geology

Geophysical and geological information indicate that the Adriatic Sea and the Po Valley are associated with a tectonic microplate—identified as the Apulian or Adriatic Plate—that separated from the African Plate during the Mesozoic era. This separation began in the Middle and Late Triassic, when limestone began to be deposited in the area. Between the Norian and Late Cretaceous, the Adriatic and Apulia Carbonate Platforms formed as a thick series of carbonate sediments (dolomites and limestones), up to 8,000 metres (26,000 ft) deep. Remnants of the former are found in the Adriatic Sea, as well as in the southern Alps and the Dinaric Alps, and remnants of the latter are seen as the Gargano Promontory and the Maiella mountain. In the Eocene and early Oligocene, the plate moved north and north-east, contributing to the Alpine orogeny (along with the African and Eurasian Plates' movements) via the tectonic uplift of the Dinarides and Alps. In the Late Oligocene, the motion was reversed and the Apennine Mountains' orogeny took place.

CARIBBEAN SEA

speciality

The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by the Yucatán Peninsula of Mexico and Central America to the west and southwest, to the ...The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by the Yucatán Peninsula of Mexico and Central America to the west and southwest, to the north by the Greater Antilles starting with Cuba, to the east by the Lesser Antilles, and to the south by the north coast of South America.The entire area of the Caribbean Sea, the numerous islands of the West Indies, and adjacent coasts, are collectively known as the Caribbean. The Caribbean Sea is one of the largest seas and has an area of about 2,754,000 km² (1,063,000 sq. mi.). The sea's deepest point is the Cayman Trough, between the Cayman Islands and Jamaica, at 7,686 m (25,220 ft) below sea level. The Caribbean coastline has many gulfs and bays: the Gulf of Gonâve, Gulf of Venezuela, Gulf of Darién, Golfo de los Mosquitos, Gulf of Paria and Gulf of Honduras.

History

The name "Caribbean" is derived from the Caribs, one of the dominant Native American groups in the region at the time of European contact during the late 15th century. After the discovery of the West Indies by Christopher Columbus in 1492, the Spanish term Antillas was assigned to the lands; stemming from this, "Sea of the Antilles" is a common alternative name for the Caribbean Sea in various European languages. During the first century of development, the Spanish dominance was The Caribbean Sea was an unknown body of water to the populations of Eurasia until 1492, when Christopher Columbus first sailed into Caribbean waters on a quest to find a sea route to Asia. At that time the Western Hemisphere in general was unknown to Europeans. Following the discovery of the islands by Columbus, the area was quickly colonised by several Western cultures (initially Spain, then later Portugal, England, the Dutch Republic, France and Denmark). Following the colonisation of the Caribbean islands, the Caribbean Sea became a busy area for European-based undisputed.

Geology

The Caribbean Sea is an oceanic sea largely situated on the Caribbean Plate. The Caribbean Sea is separated from the ocean by several island arcs of various ages. The youngest of them stretches from the Lesser Antilles to the Virgin Islands to the north east of Trinidad and Tobago off the coast of Venezuela. This arc was formed by the collision of the South American Plate with the Caribbean Plate and includes active and extinct volcanoes such as Mount Pelee, the Quill (volcano) on Sint Eustatius in the Caribbean Netherlands and Morne Trois Pitons on Dominica. The larger islands in the northern part of the sea Cuba, Haiti, Jamaica and Puerto Rico lie on an older island arc. The geological age of the Caribbean Sea is not known with certainty but is estimated to have an age between 160 and 180 million years and was formed by a horizontal fracture that split the supercontinent called Pangea in the Mesozoic Era. It is assumed that the proto-caribbean basin existed in the Devonian period. In the early Carboniferous movement of Gondwana to the north and its convergence with the Euramerica basin decreased in size. 

NORTH SEA

speciality

The North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia, Germany, the Netherlands, Belgium, and FranceThe North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia Germany, the Netherlands, Belgium, and France. An epeiric (or "shelf") sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than 970 kilometres (600 mi) long and 580 kilometres (360 mi) wide, with an area of around 750,000 square kilometres (290,000 sq mi).Historically, the North Sea has featured prominently in geopolitical and military affairs, particularly in Northern Europe but also globally through the power northern Europeans projected worldwide during much of the Middle Ages and into the modern era. The North Sea was the centre of the Vikings' rise. Subsequently, the Hanseatic League, the Netherlands, and the British each sought to dominate the North Sea and thus the access to the markets and resources of the world. As Germany's only outlet to the ocean, the North Sea continued to be strategically important through both World Wars.

Geography

The North Sea is bounded by the Orkney Islands and east coast of Great Britain to the west and the northern and central European mainland to the east and south, including Norway, Denmark, Germany, the Netherlands, Belgium, and France. In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively.In the north it is bordered by the Shetland Islands, and connects with the Norwegian Sea, which lies in the very north-eastern part of the Atlantic.

Natural history

Copepods and other zooplankton are plentiful in the North Sea. These tiny organisms are crucial elements of the food chain supporting many species of fish. Over 230 species of fish live in the North Sea. Cod, haddock, whiting, saithe, plaice, sole, mackerel, herring, pouting, sprat, and sandeel are all very common and are fished commercially.Due to the various depths of the North Sea trenches and differences in salinity, temperature, and water movement, some fish such as blue-mouth redfish and rabbitfish reside only in small areas of the North Sea.Crustaceans are also commonly found throughout the sea. Norway lobster, deep-water prawns, and brown shrimp are all commercially fished, but other species of lobster, shrimp, oyster, mussels and clams all live in the North Sea. Recently non-indigenous species have become established including the Pacific oyster and Atlantic jackknife clam.

History

Through history various names have been used for the North Sea. One of the earliest recorded names was Septentrionalis Oceanus, or "Northern Ocean," which was cited by Pliny. The name "North Sea" probably came into English, however, via the Dutch "Noordzee", who named it thus either in contrast with the Zuiderzee ("South Sea"), located south of Frisia, or simply because the sea is generally to the north of the Netherlands. Before the adoption of "North Sea," the names used in English were "German Sea" or "German Ocean", the latter referred to the Latin name "Oceanus Germanicus" and they persisted even into the 1830s

BLACK SEA

speciality

The Black Sea is a sea in Southeastern Europe. It is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean Seas and various straits.The Black Sea is a sea in Southeastern Europe. It is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean Seas and various straits. The Bosphorus Strait connects it to the Sea of Marmara, and the Strait of the Dardanelles connects that sea to the Aegean Sea region of the Mediterranean. These waters separate eastern Europe and western Asia. The Black Sea is also connected to the Sea of Azov by the Strait of Kerch.The Black Sea has an area of 436,400 km2 (168,500 sq mi) (not including the Sea of Azov)a maximum depth of 2,212 m (7,257 ft),[2] and a volume of 547,000 km3 (131,000 cu mi).The Black Sea forms in an east-west trending elliptical depression which lies between Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine.It is constrained by the Pontic Mountains to the south and by the Caucasus Mountains to the east, and features a wide shelf to the northwest. The longest east-west extent is about 1,175 km (730 mi).

Geology and bathymetry

The geological origins of the basin can be traced back to two distinct relict back-arc basins which were initiated by the splitting of an Albian volcanic arc and the subduction of both the Paleo- and Neo-Tethys Oceans, but the timings of these events remain controversial. Since its initiation, compressional tectonic environments led to subsidence in the basin, interspersed with extensional phases resulting in large-scale volcanism and numerous orogenies, causing the uplift of the Greater Caucasus, Pontides, Southern Crimean Peninsula and Balkanides mountain ranges.

Hydrology

The Black Sea is a marginal sea and is the world’s largest body of water with a meromictic basin. The deep waters do not mix with the upper layers of water that receive oxygen from the atmosphere. As a result, over 90% of the deeper Black Sea volume is anoxic water. The Black Sea’s circulation patterns are primarily controlled by basin topography and fluvial inputs, which result in a strongly stratified vertical structure. Because of the extreme stratification, it is classified as a salt wedge estuary.

ARABIAN SEA

Speciality

The Arabian Sea is a region of the northern Indian Ocean bounded on the north by Pakistan and Iran, on the southwest by northeastern Somalia, on the east by India, and on the west by the Arabian PeninsulThe Arabian Sea is a region of the northern Indian Ocean bounded on the north by Pakistan and Iran, on the southwest by northeastern Somalia, on the east by India, and on the west by the Arabian Peninsula. Some of the ancient names of this body of water include Sindhu Sagar meaning "Sea of Sindh" in Sanskrit and Erythraean Sea.

Description

The Arabian Sea's surface area is about 3,862,000 km2 (1,491,130 sq mi).The maximum width of the Sea is approximately 2,400 km (1,490 mi), and its maximum depth is 4,652 metres (15,262 ft). The biggest river flowing into the Sea is the Indus River.The Arabian Sea has two important branches — the Gulf of Aden in the southwest, connecting with the Red Sea through the strait of Bab-el-Mandeb; and the Gulf of Oman to the northwest, connecting with the Persian Gulf. There are also the gulfs of Cambay and Kutch on the Indian coast.The countries with coastlines on the Arabian Sea are Somalia, Djibouti, Yemen, Oman, Iran, Pakistan, India and the Maldives. There are several large cities on the sea's coast including Karachi, Gwadar, Pasni, Ormara, Aden, Muscat, Mumbai, Keti Bandar, Salalah, Duqm and Kochi.

Trade routes

The Arabian Sea has been an important marine trade route since the era of the coastal sailing vessels from possibly as early as the 3rd millennium BCE, certainly the late 2nd millennium BCE through the later days known as the Age of Sail. By the time of Julius Caesar, several well-established combined land-sea trade routes depended upon water transport through the Sea around the rough inland terrain features to its north.These routes usually began in the Far East or down river from Madhya Pradesh with transshipment via historic Bharuch (Bharakuccha), traversed past the inhospitable coast of today's Iran then split around Hadhramaut into two streams north into the Gulf of Aden and thence into the Levant, or south into Alexandria via Red Sea ports such as Axum. Each major route involved transhipping to pack animal caravan, travel through desert country and risk of bandits and extortionate tolls by local potentiates.