Arctic Ocean

Arctic Ocean

Overview

The Arctic Ocean, located in the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

 and mostly in the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 north polar
North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets its surface...

 region, is the smallest and shallowest of the world's five major ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

ic divisions. The International Hydrographic Organization
International Hydrographic Organization
The International Hydrographic Organization is the inter-governmental organisation representing the hydrographic community. It enjoys observer status at the UN and is the recognised competent authority on hydrographic surveying and nautical charting...

 (IHO) recognizes it as an ocean, although some oceanographers
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...

 call it the Arctic Mediterranean Sea or simply the Arctic Sea, classifying it as one of the mediterranean seas
Mediterranean sea (oceanography)
In oceanography, a mediterranean sea is a mostly enclosed sea that has limited exchange of water with outer oceans and where the water circulation is dominated by salinity and temperature differences rather than winds....

 of the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

. Alternatively, the Arctic Ocean can be seen as the northernmost part of the all-encompassing World Ocean
World Ocean
The World Ocean, world ocean, or global ocean, is the interconnected system of the Earth's oceanic waters, and comprises the bulk of the hydrosphere, covering almost 71% of the Earth's surface, with a total volume of 1.332 billion cubic kilometres.The unity and continuity of the World Ocean, with...

.

Almost completely surrounded by Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

 and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, the Arctic Ocean is partly covered by sea ice
Sea ice
Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

 throughout the year (and almost completely in winter).
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Encyclopedia

The Arctic Ocean, located in the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

 and mostly in the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 north polar
North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets its surface...

 region, is the smallest and shallowest of the world's five major ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

ic divisions. The International Hydrographic Organization
International Hydrographic Organization
The International Hydrographic Organization is the inter-governmental organisation representing the hydrographic community. It enjoys observer status at the UN and is the recognised competent authority on hydrographic surveying and nautical charting...

 (IHO) recognizes it as an ocean, although some oceanographers
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...

 call it the Arctic Mediterranean Sea or simply the Arctic Sea, classifying it as one of the mediterranean seas
Mediterranean sea (oceanography)
In oceanography, a mediterranean sea is a mostly enclosed sea that has limited exchange of water with outer oceans and where the water circulation is dominated by salinity and temperature differences rather than winds....

 of the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

. Alternatively, the Arctic Ocean can be seen as the northernmost part of the all-encompassing World Ocean
World Ocean
The World Ocean, world ocean, or global ocean, is the interconnected system of the Earth's oceanic waters, and comprises the bulk of the hydrosphere, covering almost 71% of the Earth's surface, with a total volume of 1.332 billion cubic kilometres.The unity and continuity of the World Ocean, with...

.

Almost completely surrounded by Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

 and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, the Arctic Ocean is partly covered by sea ice
Sea ice
Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

 throughout the year (and almost completely in winter). The Arctic Ocean's temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

 and salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...

 vary season
Season
A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

ally as the ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

 cover melts and freezes; its salinity is the lowest on average of the five major oceans, due to low evaporation
Evaporation
Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....

, heavy freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 inflow from river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s and stream
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...

s, and limited connection and outflow to surrounding oceanic waters with higher salinities. The summer shrinking of the ice has been quoted at 50%. The US National Snow and Ice Data Center
National Snow and Ice Data Center
The National Snow and Ice Data Center, or NSIDC, is a United States information and referral center in support of polar and cryospheric research...

 (NSIDC) uses satellite data to provide a daily record of Arctic sea ice cover and the rate of melting compared to an average period and specific past years.

History



For much of European history
History of Europe
History of Europe describes the history of humans inhabiting the European continent since it was first populated in prehistoric times to present, with the first human settlement between 45,000 and 25,000 BC.-Overview:...

, the North Polar
North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets its surface...

 regions remained largely unexplored and their geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

 conjectural. Pytheas
Pytheas
Pytheas of Massalia or Massilia , was a Greek geographer and explorer from the Greek colony, Massalia . He made a voyage of exploration to northwestern Europe at about 325 BC. He travelled around and visited a considerable part of Great Britain...

 of Massilia recorded an account of a journey northward in 325 BC, to a land he called "Eschate Thule
Thule
Thule Greek: Θούλη, Thoulē), also spelled Thula, Thila, or Thyïlea, is, in classical European literature and maps, a region in the far north. Though often considered to be an island in antiquity, modern interpretations of what was meant by Thule often identify it as Norway. Other interpretations...

," where the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

 only set for three hours each day and the water was replaced by a congealed substance "on which one can neither walk nor sail
Sailing
Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...

." He was probably describing loose sea ice known today as "growler
Iceberg
An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...

s", or "bergy bits." His "Thule" may have been Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

, though Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 is more often suggested.

Early cartographer
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...

s were unsure whether to draw the region around the North Pole as land (as in Johannes Ruysch
Johannes Ruysch
Johannes Ruysch , a.k.a. Johann Ruijsch or Giovanni Ruisch was an explorer, cartographer, astronomer, manuscript illustrator and painter from the Low Countries who produced a famous map of the world: the second oldest known printed representation of the New World...

's map of 1507, or Gerardus Mercator
Gerardus Mercator
thumb|right|200px|Gerardus MercatorGerardus Mercator was a cartographer, born in Rupelmonde in the Hapsburg County of Flanders, part of the Holy Roman Empire. He is remembered for the Mercator projection world map, which is named after him...

's map of 1595) or water (as with Martin Waldseemüller
Martin Waldseemüller
Martin Waldseemüller was a German cartographer...

's world map of 1507). The fervent desire of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

an merchants for a northern passage to "Cathay
Cathay
Cathay is the Anglicized version of "Catai" and an alternative name for China in English. It originates from the word Khitan, the name of a nomadic people who founded the Liao Dynasty which ruled much of Northern China from 907 to 1125, and who had a state of their own centered around today's...

" (China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

) caused water to win out, and by 1723 mapmakers such as Johann Homann
Johann Homann
Johann Baptist Homann was a German geographer and cartographer, who made maps of the Americas.Homann was born in Oberkammlach near Kammlach, which is now in Bavaria. Although educated at a Jesuit school, he eventually converted to Protestantism. In 1715 Homann was appointed Imperial Geographer of...

 featured an extensive "Oceanus Septentrionalis" at the northern edge of their charts.

The few expeditions to penetrate much beyond the Arctic Circle
Arctic Circle
The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....

 in this era added only small islands, such as Novaya Zemlya
Novaya Zemlya
Novaya Zemlya , also known in Dutch as Nova Zembla and in Norwegian as , is an archipelago in the Arctic Ocean in the north of Russia and the extreme northeast of Europe, the easternmost point of Europe lying at Cape Flissingsky on the northern island...

 (11th century) and Spitsbergen (1596), though since these were often surrounded by pack-ice
Drift ice
Drift ice is ice that floats on the surface of the water in cold regions, as opposed to fast ice, which is attached to a shore. Usually drift ice is carried along by winds and sea currents, hence its name, "drift ice"....

 their northern limits were not so clear. The makers of navigational chart
Nautical chart
A nautical chart is a graphic representation of a maritime area and adjacent coastal regions. Depending on the scale of the chart, it may show depths of water and heights of land , natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made aids...

s, more conservative than some of the more fanciful cartographers, tended to leave the region blank, with only fragments of known coastline sketched in.

This lack of knowledge of what lay north of the shifting barrier of ice gave rise to a number of conjectures. In England and other European nations, the myth of an "Open Polar Sea" was persistent. John Barrow
Sir John Barrow, 1st Baronet
Sir John Barrow, 1st Baronet, FRS, FRGS was an English statesman.-Career:He was born the son of Roger Barrow in the village of Dragley Beck, in the parish of Ulverston then in Lancashire, now in Cumbria...

, long time Second Secretary of the British Admiralty
Admiralty
The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...

, promoted exploration
Arctic exploration
Arctic exploration is the physical exploration of the Arctic region of the Earth. The region that surrounds the North Pole. It refers to the historical period during which mankind has explored the region north of the Arctic Circle...

 of the region from 1818 to 1845 in search of this.

In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in the 1850s and '60s, the explorers Elisha Kane
Elisha Kane
Elisha Kent Kane was a medical officer in the United States Navy during the first half of the 19th century. He was a member of two Arctic expeditions to rescue the explorer Sir John Franklin...

 and Isaac Israel Hayes
Isaac Israel Hayes
Isaac Israel Hayes was an Arctic explorer and physician.Hayes was born in Chester County, Pennsylvania. After completing his medical studies at the University of Pennsylvania, Hayes signed on as ship's surgeon for an 1853-5 expedition led by Elisha Kent Kane to search for John Franklin...

 both claimed to have seen part of this elusive body of water. Even quite late in the century, the eminent authority Matthew Fontaine Maury
Matthew Fontaine Maury
Matthew Fontaine Maury , United States Navy was an American astronomer, historian, oceanographer, meteorologist, cartographer, author, geologist, and educator....

 included a description of the Open Polar Sea in his textbook The Physical Geography of the Sea (1883). Nevertheless, as all the explorer
Exploration
Exploration is the act of searching or traveling around a terrain for the purpose of discovery of resources or information. Exploration occurs in all non-sessile animal species, including humans...

s who travelled closer and closer to the pole reported, the polar ice cap
Ice cap
An ice cap is an ice mass that covers less than 50 000 km² of land area . Masses of ice covering more than 50 000 km² are termed an ice sheet....

 is quite thick, and persists year-round.

Fridtjof Nansen
Fridtjof Nansen
Fridtjof Wedel-Jarlsberg Nansen was a Norwegian explorer, scientist, diplomat, humanitarian and Nobel Peace Prize laureate. In his youth a champion skier and ice skater, he led the team that made the first crossing of the Greenland interior in 1888, and won international fame after reaching a...

 was the first to make a nautical
Seamanship
Seamanship is the art of operating a ship or boat.It involves a knowledge of a variety of topics and development of specialised skills including: navigation and international maritime law; weather, meteorology and forecasting; watchstanding; ship-handling and small boat handling; operation of deck...

 crossing of the Arctic Ocean, in 1896. The first surface crossing of the ocean was led by Wally Herbert
Wally Herbert
Sir Walter William "Wally" Herbert was a British polar explorer, writer and artist. In 1969 he became the first man to walk undisputed to the North Pole, on the 60th anniversary of Robert Peary's famous, but disputed, expedition...

 in 1969, in a dog sled
Dog sled
A dog sled is a sled pulled by one or more sled dogs used to travel over ice and through snow. Numerous types of sleds are used, depending on their function. They can be used for dog sled racing.-History:...

 expedition from Alaska to Svalbard
Svalbard
Svalbard is an archipelago in the Arctic, constituting the northernmost part of Norway. It is located north of mainland Europe, midway between mainland Norway and the North Pole. The group of islands range from 74° to 81° north latitude , and from 10° to 35° east longitude. Spitsbergen is the...

, with air support.

Since 1937, Soviet and Russian manned drifting ice stations
Soviet and Russian manned drifting ice stations
Soviet and Russian manned drifting ice stations are important contributors to exploration of the Arctic. The stations are named North Pole Soviet and Russian manned drifting ice stations are important contributors to exploration of the Arctic. The stations are named North Pole Soviet and...

 have extensively monitored the Arctic Ocean. Scientific settlements were established on the drift ice and carried thousands of kilometres by ice floes.

Geography



The Arctic Ocean occupies a roughly circular basin and covers an area of about 14056000 km² (5,427,051.9 sq mi), almost the size of Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. The coastline is 45390 km (28,204.1 mi) long. It is surrounded by the land masses of Eurasia, North America, Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

, and by several island
Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

s.

It is generally taken to include Baffin Bay
Baffin Bay
Baffin Bay , located between Baffin Island and the southwest coast of Greenland, is a marginal sea of the North Atlantic Ocean. It is connected to the Atlantic via Davis Strait and the Labrador Sea...

, Barents Sea
Barents Sea
The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...

, Beaufort Sea
Beaufort Sea
The Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canada's Arctic islands. The sea is named after hydrographer Sir Francis Beaufort...

, Chukchi Sea
Chukchi Sea
Chukchi Sea is a marginal sea of the Arctic Ocean. It is bounded on the west by the De Long Strait, off Wrangel Island, and in the east by Point Barrow, Alaska, beyond which lies the Beaufort Sea. The Bering Strait forms its southernmost limit and connects it to the Bering Sea and the Pacific...

, East Siberian Sea
East Siberian Sea
The East Siberian Sea is a marginal sea in the Arctic Ocean. It is located between the Arctic Cape to the north, the coast of Siberia to the south, the New Siberian Islands to the west and Cape Billings, close to Chukotka, and Wrangel Island to the east...

, Greenland Sea
Greenland Sea
The Greenland Sea is a body of water that borders Greenland to the west, the Svalbard archipelago to the east, Fram Strait and the Arctic Ocean to the north, and the Norwegian Sea and Iceland to the south. The Greenland Sea is often defined as part of the Arctic Ocean, sometimes as part of the...

, Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...

, Hudson Strait
Hudson Strait
Hudson Strait links the Atlantic Ocean to Hudson Bay in Canada. It lies between Baffin Island and the northern coast of Quebec, its eastern entrance marked by Cape Chidley and Resolution Island. It is long...

, Kara Sea
Kara Sea
The Kara Sea is part of the Arctic Ocean north of Siberia. It is separated from the Barents Sea to the west by the Kara Strait and Novaya Zemlya, and the Laptev Sea to the east by the Severnaya Zemlya....

, Laptev Sea
Laptev Sea
The Laptev Sea is a marginal sea of the Arctic Ocean. It is located between the northern coast of Siberia, the Taimyr Peninsula, Severnaya Zemlya and the New Siberian Islands. Its northern boundary passes from the Arctic Cape to a point with co-ordinates of 79°N and 139°E, and ends at the Anisiy...

, White Sea
White Sea
The White Sea is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the northeast. The whole of the White Sea is under Russian sovereignty and considered to be part of...

 and other tributary bodies of water. It is connected to the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 by the Bering Strait
Bering Strait
The Bering Strait , known to natives as Imakpik, is a sea strait between Cape Dezhnev, Chukotka Autonomous Okrug, Russia, the easternmost point of the Asian continent and Cape Prince of Wales, Alaska, USA, the westernmost point of the North American continent, with latitude of about 65°40'N,...

 and to the Atlantic Ocean through the Greenland Sea
Greenland Sea
The Greenland Sea is a body of water that borders Greenland to the west, the Svalbard archipelago to the east, Fram Strait and the Arctic Ocean to the north, and the Norwegian Sea and Iceland to the south. The Greenland Sea is often defined as part of the Arctic Ocean, sometimes as part of the...

 and Labrador Sea
Labrador Sea
The Labrador Sea is an arm of the North Atlantic Ocean between the Labrador Peninsula and Greenland. The sea is flanked by continental shelves to the southwest, northwest, and northeast. It connects to the north with Baffin Bay through the Davis Strait...

.

Extent




Underwater features


An underwater ridge
Mid-ocean ridge
A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges , typically having a valley known as a rift running along its spine, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading...

, the Lomonosov Ridge
Lomonosov Ridge
The Lomonosov Ridge is an unusual underwater ridge of continental crust in the Arctic Ocean. It spans 1800 km from the New Siberian Islands, as it is part of Eurasia, over the central part of the ocean to Ellesmere Island of the Canadian Arctic Archipelago. The width of the Lomonosov Ridge varies...

, divides the deep sea North Polar Basin
North Polar Basin
The North Polar Basin is an oceanic basin in the Arctic Ocean, consisting of two main parts, the Amerasian Basin and the Eurasian Basin , which are separated by the Lomonosov Ridge, a mid-ocean ridge running between north Greenland and the New Siberian Islands...

 into two oceanic basin
Oceanic basin
Hydrologically, an oceanic basin may be anywhere on Earth that is covered by seawater, but geologically ocean basins are large geologic basins that are below sea level...

s: the Eurasian Basin
Eurasian Basin
The Eurasian Basin, is one of the two major basins into which the North Polar Basin of the Arctic Ocean is split by the Lomonosov Ridge . It is an extension of the North Atlantic Basin. It is further split by the Nansen-Gakkel Ridge into the Nansen Basin and the Fram Basin...

, which is between 4000 and 4500 m (13,123.4 and 14,763.8 ft) deep, and the Amerasian Basin
Amerasian Basin
The Amerasian Basin is one of the two major basins into which the North Polar Basin of the Arctic Ocean is split by the Lomonosov Ridge . It extends from Ellesmere Island to the East Siberian Sea...

 (sometimes called the North American, or Hyperborean Basin), which is about 4000 m (13,123.4 ft) deep. The bathymetry
Bathymetry
Bathymetry is the study of underwater depth of lake or ocean floors. In other words, bathymetry is the underwater equivalent to hypsometry. The name comes from Greek βαθύς , "deep", and μέτρον , "measure"...

 of the ocean bottom is marked by fault-block ridges, abyssal plain
Abyssal plain
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 metres. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest...

s, ocean deeps
Oceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor....

, and basins
Oceanic basin
Hydrologically, an oceanic basin may be anywhere on Earth that is covered by seawater, but geologically ocean basins are large geologic basins that are below sea level...

. The average depth of the Arctic Ocean is 1038 m (3,405.5 ft). The deepest point is in the Eurasian Basin, at 5450 m (17,880.6 ft).

The two major basins are further subdivided by ridges into the Canada Basin (between Alaska/Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 and the Alpha Ridge
Alpha Ridge
The Alpha Ridge is a major volcanic ridge under the Arctic Ocean between the Canada Basin and the Lomonosov Ridge. It was active during the formation of the Amerasian Basin. It was discovered in 1963. The highest elevation is about 2.7 km over the ocean floor. It is 200 to 450 km wide...

), Makarov Basin (between the Alpha and Lomonosov Ridges), Fram Basin
Fram Basin
Fram Basin is the lowest point of the Arctic Ocean at a depth of 4,665 m.The Fram Basin is a part of the Eurasian Basin, and lies between the Nansen Cordillera and the Lomonosov Ridge. The Barents Abyssal Plain is located at the center of the Fram Basin....

 (between Lomonosov and Gakkel
Gakkel Ridge
The Gakkel Ridge is a mid-oceanic ridge, a divergent tectonic plate boundary between the North American Plate and the Eurasian Plate. It is located in the Arctic Ocean between Greenland and Siberia, and has a length of about 1,800 kilometers...

 ridges), and Nansen Basin (Amundsen Basin) (between the Gakkel Ridge and the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

 that includes the Franz Josef Land
Franz Josef Land
Franz Josef Land, Franz Joseph Land, or Francis Joseph's Land is an archipelago located in the far north of Russia. It is found in the Arctic Ocean north of Novaya Zemlya and east of Svalbard, and is administered by Arkhangelsk Oblast. Franz Josef Land consists of 191 ice-covered islands with a...

).

Water flow


The Arctic Ocean contains a major choke point
Choke point
In military strategy, a choke point is a geographical feature on land such as a valley, defile or a bridge, or at sea such as a strait which an armed force is forced to pass, sometimes on a substantially narrower front, and therefore greatly decreasing its combat power, in order to reach its...

 in the southern Chukchi Sea, which provides access to the Pacific Ocean through the Bering Strait between Alaska and Eastern Siberia. Subject to ice conditions, the Arctic Ocean provides the shortest marine link between the extremes of eastern and western Russia. There are several floating research station
Research station
A research station is a station built for the purpose of conducting scientific research. Research station sites might include outer space and oceans. Many nations have research stations in Antarctica; Showa Station, Halley and Troll are examples...

s in the Arctic, operated by the US and Russia.

The greatest inflow
Inflow (hydrology)
In hydrology, the inflow of a body of water is the source of the water in the body of water. It can also refer to the average volume of incoming water in unit time. It is contrasted with outflow....

 of water comes from the Atlantic by way of the Norwegian Current
Norwegian Current
The Norwegian Current is a water current that flows north-easterly along the Atlantic coast of Norway at depths of between 50 and 100 meters...

, which then flows along the Eurasian coast. Water also enters from the Pacific via the Bering Strait. The East Greenland Current
East Greenland Current
The East Greenland Current is a cold, low salinity current that extends from Fram Strait to Cape Farewell . The current is located off the eastern coast of Greenland along the Greenland continental margin. The current cuts through the Nordic Seas and through the Denmark Strait...

 carries the major outflow
Discharge (hydrology)
In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...

.

Ice covers most of the ocean surface year-round, causing subfreezing air temperatures much of the time. The Arctic is a major source of very cold air
Cold front
A cold front is defined as the leading edge of a cooler mass of air, replacing a warmer mass of air.-Development of cold front:The cooler and denser air wedges under the less-dense warmer air, lifting it...

 that moves toward the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

, meeting with warmer air
Warm front
A warm front is a density discontinuity located at the leading edge of a homogeneous warm air mass, and is typically located on the equator-facing edge of an isotherm gradient...

 at latitude 60°N and causing rain
Rain
Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...

 and snow
Snow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...

. This flow is the lower portion of the polar cell, the highest (by latitude) of the three principal circulation cells of the Earth's atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

 each spanning thirty degrees of latitude. Marine life
Marine biology
Marine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather...

 abounds in open areas, especially the more southerly waters. The ocean's major port
Port
A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land....

s are the cities of Murmansk
Murmansk
Murmansk is a city and the administrative center of Murmansk Oblast, Russia. It serves as a seaport and is located in the extreme northwest part of Russia, on the Kola Bay, from the Barents Sea on the northern shore of the Kola Peninsula, not far from Russia's borders with Norway and Finland...

, Arkhangelsk
Arkhangelsk
Arkhangelsk , formerly known as Archangel in English, is a city and the administrative center of Arkhangelsk Oblast, Russia. It lies on both banks of the Northern Dvina River near its exit into the White Sea in the north of European Russia. The city spreads for over along the banks of the river...

 and Prudhoe Bay
Prudhoe Bay, Alaska
Prudhoe Bay or Sagavanirktok is a census-designated place located in North Slope Borough in the U.S. state of Alaska. As of the 2010 census, the population of the CDP was 2,174 people; however, at any given time several thousand transient workers support the Prudhoe Bay oil field...

.

Salinity and temperature


In large parts of the Arctic Ocean, the top layer (about 50 m) is of lower salinity and lower temperature than the rest. It remains relatively stable, because the salinity effect on density is bigger than the temperature effect. It is fed by the freshwater input of the big Siberian and Canadian streams (Ob, Yenissey, Lena, MacKenzie), the water of which quasi floats on the saltier, denser, deeper ocean water. Between this lower salinity layer and the bulk of the ocean lies the so called halocline
Halocline
In oceanography, a halocline is a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water. Because salinity affects the density of seawater, it can play a role in its vertical stratification...

, in which both salinity and temperature are rising with increasing depth. Any convection
Convection
Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....

 eddies caused by the temperature difference between the cold ocean surface and the warmer depth stop at this thermocline, leaving only heat conduction
Heat conduction
In heat transfer, conduction is a mode of transfer of energy within and between bodies of matter, due to a temperature gradient. Conduction means collisional and diffusive transfer of kinetic energy of particles of ponderable matter . Conduction takes place in all forms of ponderable matter, viz....

 as upward heat transport mechanism, which is orders of magnitude smaller. Without this insulation effect, there would be much less Arctic sea ice. The salinity and temperature pattern of the Arctic Ocean can be quite complex, being dependent on the different flows into and out of the Arctic region.

Ice cap



Much of the Arctic Ocean is covered by an ice "cap" which varies in extent and thickness seasonally. The mean extent of the cap, which is composed of mostly contiguous sea ice, is decreasing since 1980 from the average winter value of 15600000 square kilometre at a rate of 3% per decade. The seasonal variations are about 7000000 square kilometre with the maximum in April and minimum in September. The sea ice is affected by wind and ocean currents which can move and rotate very large areas of ice. Zones of compression also arise, where the ice piles up to form pack ice.

Shelves


The Arctic Ocean is encompassed by the Continental shelf of Russia
Continental shelf of Russia
The continental shelf of Russia is a continental shelf adjacent to Russia. Geologically, the extent of the shelf is defined as the entirety of the continental shelves adjacent to Russia's coast...

, which consists of three separate, smaller shelves, the Barents, Chukchi
Chukchi Sea Shelf
The Chukchi Sea Shelf or Chukchi Shelf is the easternmost part of the Continental shelf of Russia and the westernmost part of the Continental shelf of the United States...

 and Siberian
Siberian Shelf
The Siberian Shelf, one of the Arctic Ocean coastal shelves , is the largest continental shelf of the Earth, a part of the continental shelf of Russia. It extends from the continent of Eurasia in the general area of North Siberia into the Arctic Ocean. It stretches to offshore. It is relatively...

. Of these three, the Siberian shelf is the largest shelf in the world. The Siberian shelf holds large oil and gas reserves, and the Chukchi shelf forms the border between Russian and the United States as stated in the USSR–USA Maritime Boundary Agreement.

Natural hazards


Iceberg
Iceberg
An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...

s occasionally break away from northern Ellesmere Island, and icebergs are formed from glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s in western Greenland and extreme northeastern Canada. These icebergs pose a hazard to ships, most famously the Titanic. Permafrost
Permafrost
In geology, permafrost, cryotic soil or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of...

 is found on most islands. The ocean is virtually icelocked from October to June, and ship
Ship
Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

s are subject to superstructure
Superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships...

 icing
Icing (nautical)
Icing on ships is a serious hazard where cold temperatures combined with high wind speed result in spray blown off the sea freezing immediately on contact with the ship...

 from October to May. Before the advent of modern icebreaker
Icebreaker
An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters. Although the term usually refers to ice-breaking ships, it may also refer to smaller vessels .For a ship to be considered an icebreaker, it requires three traits most...

s, ships sailing the Arctic Ocean risked being trapped or crushed by sea ice (although the Baychimo
Baychimo
The Baychimo was a steel 1,322 ton cargo steamer built in 1914 in Sweden and owned by the Hudson's Bay Company, used to trade pelts for provisions in Inuit settlements along the Victoria Island coast of the Northwest Territories of Canada...

drifted through the Arctic Ocean untended for decade
Decade
A decade is a period of 10 years. The word is derived from the Ancient Greek dekas which means ten. This etymology is sometime confused with the Latin decas and dies , which is not correct....

s despite these hazards).

Major ports and harbors


Some notable ports and harbours from west to east include:
  • United States
    • Barrow, Alaska
      Barrow, Alaska
      Barrow is the largest city of the North Slope Borough in the U.S. state of Alaska. It is one of the northernmost cities in the world and is the northernmost city in the United States of America, with nearby Point Barrow being the nation's northernmost point. Barrow's population was 4,212 at the...

    • Prudhoe Bay, Alaska
      Prudhoe Bay, Alaska
      Prudhoe Bay or Sagavanirktok is a census-designated place located in North Slope Borough in the U.S. state of Alaska. As of the 2010 census, the population of the CDP was 2,174 people; however, at any given time several thousand transient workers support the Prudhoe Bay oil field...

  • Canada
    • Churchill, Manitoba
      Churchill, Manitoba
      Churchill is a town on the shore of Hudson Bay in Manitoba, Canada. It is most famous for the many polar bears that move toward the shore from inland in the autumn, leading to the nickname "Polar Bear Capital of the World" that has helped its growing tourism industry.-History:A variety of nomadic...

    • Inuvik, Northwest Territories
      Inuvik, Northwest Territories
      Inuvik is a town in the Northwest Territories of Canada and is the administrative centre for the Inuvik Region.The population as of the 2006 Census was 3,484, but the two previous census counts show wide fluctuations due to economic conditions: 2,894 in 2001 and 3,296 in 1996...

    • Nanisivik, Nunavut
      Nanisivik, Nunavut
      Nanisivik was a company town which was built in 1975 to support the lead-zinc mining and mineral processing operations for the Nanisivik Mine, in production between 1976 and 2002...

    • Tuktoyaktuk
  • Norway
    • Longyearbyen
      Longyearbyen
      Longyearbyen is the largest settlement and the administrative centre of Svalbard, Norway. It is located on the western coast of Spitsbergen, the largest island of the Svalbard archipelago, on the southern side on Adventfjorden , which continues inland with Adventdalen...

    • Kirkenes
      Kirkenes
      is a town in the municipality of Sør-Varanger in the county of Finnmark in the far northeast of Norway...

    • Vardø
      Vardø
      is a town and a municipality in Finnmark county in the extreme northeast part of Norway.Vardø was established as a municipality on 1 January 1838 . The law required that all cities should be separated from their rural districts, but because of a low population and very few voters, this was...

  • Russia
    • Murmansk
      Murmansk
      Murmansk is a city and the administrative center of Murmansk Oblast, Russia. It serves as a seaport and is located in the extreme northwest part of Russia, on the Kola Bay, from the Barents Sea on the northern shore of the Kola Peninsula, not far from Russia's borders with Norway and Finland...

    • Arkhangelsk
      Arkhangelsk
      Arkhangelsk , formerly known as Archangel in English, is a city and the administrative center of Arkhangelsk Oblast, Russia. It lies on both banks of the Northern Dvina River near its exit into the White Sea in the north of European Russia. The city spreads for over along the banks of the river...

    • Labytnangi
      Labytnangi
      Labytnangi is a town in Yamalo-Nenets Autonomous Okrug, Russia, located on the left bank of the Ob River, northwest of Salekhard. Population:...

      /Salekhard
      Salekhard
      -International relations:-Twin towns/sister cities:Salekhard is twinned with:*Azov, Rostov Oblast, Russia-External links:*...

    • Dudinka
      Dudinka
      Dudinka is a town and the administrative center of Taymyrsky Dolgano-Nenetsky District of Krasnoyarsk Krai, Russia. It was the administrative center of Taymyr Autonomous Okrug, which was merged into Krasnoyarsk Krai on January 1, 2007. It is a port in the lower reaches of the Yenisei River,...

    • Igarka
      Igarka
      Igarka is an town in Turukhansky District of Krasnoyarsk Krai, Russia, located north of the Arctic Circle. It is also a port on the Yenisei River, located away from the river's mouth...

    • Dikson
      Dikson (urban-type settlement)
      Dikson is an urban locality in Taymyrsky Dolgano-Nenetsky District of Krasnoyarsk Krai, Russia. Population: Dikson is the northernmost port in Russia and one of the northernmost settlements in the world. It is located so far north that one may experience complete darkness with no civil twilight...

    • Tiksi
      Tiksi
      Tiksi is an urban locality and the administrative center of Bulunsky District of the Sakha Republic, Russia, situated on the Arctic Ocean coast. Population: It is one of the principal ports for accessing the Laptev Sea...

    • Pevek
      Pevek
      Pevek is a town and Arctic port in Chaunsky District, part of the Chukotka Autonomous Okrug, Russia. After Anadyr and Bilibino it is the third largest town in Chukotka. Population: Municipally, the town is subordinated to Chaunsky Municipal district and together with Apapelgino and Yanranay, is...


Climate



Under the influence of the present ice age
Quaternary glaciation
Quaternary glaciation, also known as the Pleistocene glaciation, the current ice age or simply the ice age, refers to the period of the last few million years in which permanent ice sheets were established in Antarctica and perhaps Greenland, and fluctuating ice sheets have occurred elsewhere...

, the Arctic Ocean is contained in a polar climate
Polar climate
Regions with a polar climate are characterized by a lack of warm summers . Regions with polar climate cover over 20% of the Earth. The sun shines 24 hours in the summer, and barely ever shines at all in the winter...

 characterized by persistent cold and relatively narrow annual temperature range
Temperature range
Atmospheric temperature range is the numerical difference between the minimum and maximum values of temperature observed in a given location....

s. Winters are characterized by continuous darkness
Darkness
Darkness, in contrast with brightness, is a relative absence of visible light. It is the appearance of black in a color space. When light is not present, rod and cone cells within the eye are not stimulated. This lack of stimulation means photoreceptor cells are unable to distinguish color...

 (polar night
Polar night
The polar night occurs when the night lasts for more than 24 hours. This occurs only inside the polar circles. The opposite phenomenon, the polar day, or midnight sun, occurs when the sun stays above the horizon for more than 24 hours.-Description:...

), cold and stable weather conditions, and clear skies; summers are characterized by continuous daylight
Daylight
Daylight or the light of day is the combination of all direct and indirect sunlight outdoors during the daytime. This includes direct sunlight, diffuse sky radiation, and both of these reflected from the Earth and terrestrial objects. Sunlight scattered or reflected from objects in outer space is...

 (midnight sun
Midnight sun
The midnight sun is a natural phenomenon occurring in summer months at latitudes north and nearby to the south of the Arctic Circle, and south and nearby to the north of the Antarctic Circle where the sun remains visible at the local midnight. Given fair weather, the sun is visible for a continuous...

), damp and fog
Fog
Fog is a collection of water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated...

gy weather, and weak cyclone
Cyclone
In meteorology, a cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale...

s with rain or snow.

The temperature of the surface of the Arctic Ocean is fairly constant, near the freezing point
Melting point
The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...

 of seawater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...

. Because the Arctic Ocean consists of saltwater the temperature must reach −1.8°C before freezing occurs.
The density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 of sea water, in contrast to fresh water, increases as it nears the freezing point and thus it tends to sink. It is generally necessary that the upper 100–150 meters of ocean water cools to the freezing point for sea ice
Sea ice
Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

 to form. In the winter the relatively warm ocean water exerts a moderating influence, even when covered by ice. This is one reason why the Arctic does not experience the extreme temperatures seen on the Antarctic continent.

There is considerable seasonal variation in how much pack ice of the Arctic ice pack
Polar ice packs
Polar ice packs are large areas of pack ice formed from seawater in the Earth's polar regions, known as polar ice caps: the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean, fringing the Antarctic ice sheet. Polar packs significantly change their size during...

 covers the Arctic Ocean. Much of the Arctic ice pack is also covered in snow for about 10 months of the year. The maximum snow cover is in March or April — about 20 to 50 cm (7.9 to 19.7 in) over the frozen ocean.

The climate of the Arctic region has varied significantly in the past. As recently as 55 million years ago, during the Paleocene–Eocene Thermal Maximum, the region reached an average annual temperature of 10–20 °C (50–68 F). The surface waters of the northernmost Arctic ocean warmed, seasonally at least, enough to support tropical lifeforms requiring surface temperatures of over 22 °C (71.6 °F).

Animal and plant life


Endangered marine species in the Arctic Ocean include walrus
Walrus
The walrus is a large flippered marine mammal with a discontinuous circumpolar distribution in the Arctic Ocean and sub-Arctic seas of the Northern Hemisphere. The walrus is the only living species in the Odobenidae family and Odobenus genus. It is subdivided into three subspecies: the Atlantic...

es and whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...

s. The area has a fragile ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

 which is slow to change and slow to recover from disruptions or damage. Lion's mane jellyfish
Lion's mane jellyfish
The lion's mane jellyfish is the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans, seldom found farther south than 42°N latitude. Similar jellyfish, which may be the same species, are known to inhabit...

 are abundant in the waters of the Arctic, and the banded gunnel
Banded gunnel
The Banded Gunnel is the only species of gunnel that lives in the Arctic Ocean. Very little is known about its life cycle or reproduction.-Physical characteristics:...

 is the only species of gunnel
Pholidae
The gunnels are a family, Pholidae, of fishes in the order Perciformes.They are elongated fishes native to the coasts of the northern Atlantic, Pacific and Arctic Oceans, where they inhabit intertidal and subtidal waters and eat crustaceans and molluscs.-Species:There are fifteen species in three...

 that lives in the ocean.

The Arctic Ocean has relatively little plant life except for phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...

. Phytoplankton are a crucial part of the ocean and there are massive amounts of them in the Arctic, where they feed on nutrients from rivers and the currents
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...

 of the Atlantic and Pacific oceans. During summer, the Sun is out day and night, thus enabling the phytoplankton to photosynthesize
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

 for long periods of time and reproduce quickly. However, the reverse is true in winter where they struggle to get enough light to survive.

Natural resources


Petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 field
Natural gas field
Oil and natural gas are produced by the same geological process according fossil fuel suggestion: anaerobic decay of organic matter deep under the Earth's surface. As a consequence, oil and natural gas are often found together...

s, placer deposit
Placer deposit
In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation during sedimentary processes. The name is from the Spanish word placer, meaning "alluvial sand". Placer mining is an important source of gold, and was the main technique used in the early...

s, polymetallic nodules
Manganese nodule
Polymetallic nodules, also called manganese nodules, are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. The core may be microscopically small and is sometimes completely transformed into manganese minerals by crystallization...

, sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

 and gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

 aggregate
Construction Aggregate
Construction aggregate, or simply "aggregate", is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined material in the world...

s, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, seals
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

 and whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...

s can all be found in abundance in the region.

The political dead zone near the center of the sea is also the focus of a mounting dispute between the United States, Russia, Canada, Norway, and Denmark. It is significant for the global energy market
Energy market
Energy markets are those commodities markets that deal specifically with the trade and supply of energy. Energy market may refer to an electricity market, but can also refer to other sources of energy...

 because it may hold 25% or more of the world's undiscovered oil and gas resources.

Environmental concerns




The Arctic ice pack is thinning, and in many years there is also a seasonal hole in the ozone layer
Ozone layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...

.
Reduction of the area of Arctic sea ice reduces the planet's average albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...

, possibly resulting in global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 in a positive feedback mechanism. Research shows that the Arctic may become ice free for the first time in human history between 2012 and 2040.

Many scientists are presently concerned that warming temperatures in the Arctic may cause large amounts of fresh meltwater
Meltwater
Meltwater is the water released by the melting of snow or ice, including glacial ice and ice shelfs over oceans. Meltwater is often found in the ablation zone of glaciers, where the rate of snow cover is reducing...

 to enter the North Atlantic, possibly disrupting global ocean current patterns
Thermohaline circulation
The term thermohaline circulation refers to a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes....

. Potentially severe changes in the Earth's climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

 might then ensue.

Other environmental concerns
Environmentalism
Environmentalism is a broad philosophy, ideology and social movement regarding concerns for environmental conservation and improvement of the health of the environment, particularly as the measure for this health seeks to incorporate the concerns of non-human elements...

 relate to the radioactive contamination
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...

 of the Arctic Ocean from, for example, Russian radioactive waste
Radioactive waste
Radioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine...

 dump sites in the Kara Sea and Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 nuclear test sites
Nuclear testing
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them...

 such as Novaya Zemlya
Novaya Zemlya
Novaya Zemlya , also known in Dutch as Nova Zembla and in Norwegian as , is an archipelago in the Arctic Ocean in the north of Russia and the extreme northeast of Europe, the easternmost point of Europe lying at Cape Flissingsky on the northern island...

.










See also



  • Arctic Bridge
    Arctic bridge
    The Arctic Bridge or Arctic Sea Bridge is a seasonal sea route linking Russia to Canada, specifically the Russian port of Murmansk to the Hudson Bay port of Churchill, Manitoba. Churchill is the principal seaport on Canada's northern coast and has rail and air connections to the rest of Canada...


Fauna of the Arctic
  • Extreme points of the Arctic
    Extreme points of the Arctic
    This is a list of the extreme points of the Arctic, the points of Arctic lands that are farther to the north than any other location classified by continent and country, latitude and longitude, and distance to the North Pole. The list is sorted from north to south....

  • International Arctic Science Committee
    International Arctic Science Committee
    The International Arctic Science Committee is a non-governmental organization which is composed of international science groups participating in arctic science research. IASC is an International Scientific Associate of ICSU, and was established in 1990...

  • Nordicity
    Nordicity
    Nordicity is the degree of northernness. The concept was developed by Canadian geographer Louis-Edmond Hamelin in the 1960s based on previous work done in the Soviet Union...

  • North Atlantic Current
    North Atlantic Current
    The North Atlantic Current is a powerful warm ocean current that continues the Gulf Stream northeast. West of Ireland it splits in two; one branch, the Canary Current, goes south, while the other continues north along the coast of northwestern Europe...

  • Subarctic
    Subarctic
    The Subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Alaska, Canada, the north of Scandinavia, Siberia, and northern Mongolia...


Explorers of the Arctic
  • Arctic sea ice ecology and history
  • Seven seas
    Seven Seas
    The phrase "Seven Seas" can refer either to a particular set of seven seas or to a great expanse of water in general. Today in modern times, this also includes the four oceans, and three large seas...

  • The Chukchi Cap
    Chukchi Cap
    The Chukchi Cap is a large undersea ridge in the Arctic Ocean.The cap is normally ice-covered, year-round.The United States Coast Guard Cutter Healy has been sent on multiple missions to map the poorly explored ridge....

  • Arctic Cooperation and Politics
    Arctic Cooperation and Politics
    Arctic cooperation and politics are partially coordinated via the Arctic Council, composed of the eight Arctic nations of the United States of America, Canada, Iceland, Norway, Sweden, Finland, Russia, and Denmark with Greenland and The Faroe Islands...



Further reading

  • Neatby, Leslie H., Discovery in Russian and Siberian Waters 1973 ISBN 0-8214-0124-6
  • Ray, L., and bacon, B., eds., The Arctic Ocean 1982 ISBN 0-333-31017-9
  • Thorén, Ragnar V. A., Picture Atlas of the Arctic 1969 ISBN 0-8214-0124-6

External links