Arctic Ocean: Map

Top rankings for Arctic Ocean

13rd	Top intergovernmental organizations

Wikipedia article:

Map showing all locations mentioned on Wikipedia article:

The Arctic Ocean, located in the Northern Hemisphere

and mostly in the Arctic north polar

region, is the smallest, and shallowest of the world's five major oceanic divisions. The International Hydrographic Organization (IHO) recognizes it as an ocean, although some oceanographers call it the Arctic Mediterranean Sea or simply the Arctic Sea, classifying it as one of the mediterranean seas of the Atlantic Ocean

. Alternatively, the Arctic Ocean can be seen as the northernmost lobe of the all-encompassing World Ocean.

Almost completely surrounded by Eurasia and North America, the Arctic Ocean is partly covered by sea ice throughout the year (and almost completely in winter). The Arctic Ocean's temperature and salinity vary seasonally as the ice cover melts and freezes; its salinity is the lowest on average of the five major oceans, due to low evaporation, heavy freshwater inflow from rivers and streams, and limited connection and outflow to surrounding oceanic waters with higher salinities. The summer shrinking of the ice has been quoted at 50%. The National Snow and Ice Data Center (NSIDC) use 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.

The Arctic Ocean

Geography

The Arctic Ocean occupies a roughly circular basin and covers an area of about , almost the size of Russia

. The coastline is long. It is surrounded by the land masses of Eurasia, North America, Greenland

, and by several islands. It is generally taken to include Baffin Bay

, Barents Sea

, Chukchi Sea

, Hudson Bay

, Kara Sea

, Laptev Sea

, White Sea

and other tributary bodies of water. It is connected to the Pacific Ocean

by the Bering Strait

and to the Atlantic Ocean through the Greenland Sea

and Labrador Sea

.

According to the International Hydrographic Organization, the limits of the Arctic Ocean proper (that is, excluding the seas within the Ocean) are (see the map):

A great circle line running from Cape Morris Jesup , the northernmost point of Greenland ( ) to the northernmost point of Spitsbergen (south of which line lies the Greenland Sea).
Parallel 80° North to North East Land (Nordaustlandet ).
The north shore of Nordaustlandet to its easternmost point, Cape Leigh Smith ( ).
A line running from Cape Leigh Smith to Cape Kohlsaat , the easternmost point of Franz Josef Land ( , south of which line lies the Barents Sea].
A line running from Cape Kohlsaat to Cape Molotov (Arctic Cape ), the northernmost point of Komsomolets Island ( , south of which line lies the Kara Sea).
A line running from Arctic Cape to the northernmost point of Kotelny Island ( , south of which line lies the Laptev Sea).
A line running from the northernmost point of Kotelny Island to the northernmost point of Wrangel Island ( , south of which line lies the East Siberian Sea).
A line running from the northernmost point of Wrangel Island to Point Barrow , the northernmost point of Alaska ( , south of which line lies the Chuckchi Sea).
A line running from Point Barrow to Cape Land's End on Prince Patrick Island , Northwest Territories ( , south of which line lies the Beaufort Sea).
The northwest coast of Prince Patrick Island north to Cape Leopold M'Clintock, its northernmost point ( ).
A line running from Cape Leopold M'Clintock to Cape Murray on Brock Island ( ).
The northwest coast of Brock Island north to its northernmost point ( ).
A line running from the northernmost point of Brock Island to Cape Mackay on Borden Island , its westernmost point ( ).
The northwest coast of Borden Island north to Cape Malloch ( , the northernmost point of the Northwest Territories).
A line running from Cape Malloch to Cape Isachsen on Ellef Ringnes Island , Nunavut , its northwestern most point ( ).
A line running from Cape Isachsen to the northwestern most point of Meighen Island ( ).
A line running from the northwestern most point of Meighen Island to Cape Stallworthy on Axel Heiberg Island , its northernmost point ( ).
A line running from Cape Stallworthy to Cape Colgate on Ellesmere Island , its westernmost point ( ).
The north coast of Ellesmere Island north to Cape Columbia , its northernmost point ( ).
A line running from Cape Columbia to Cape Morris Jesup (south of which line lies the Lincoln Sea ).

Arctic region

An underwater ridge, the Lomonosov Ridge, divides the deep sea North Polar Basin into two oceanic basins: the Eurasian Basin, which is between deep, and the Amerasian Basin (sometimes called the North American, or Hyperborean Basin), which is about deep. The bathymetry of the ocean bottom is marked by fault-block ridges, plains of the abyssal zone, ocean deeps, and basins. The average depth of the Arctic Ocean is . The deepest point is in the Eurasian Basin, at .

The two major basins are further subdivided by ridges into the Canada Basin (between Alaska/Canada

and the Alpha Ridge), Makarov Basin (between the Alpha and Lomonosov Ridges), Fram Basin (between Lomonosov and Gakkel ridges), and Nansen Basin (Amundsen Basin) (between the Gakkel Ridge and the continental shelf that includes the Franz Josef Land

).

The Arctic Ocean contains a major choke point 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 stations in the Arctic, operated by the US and Russia.

The greatest inflow of water comes from the Atlantic by way of the Norwegian Current, which then flows along the Eurasian coast. Water also enters from the Pacific via the Bering Strait. The East Greenland Current carries the major outflow.

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 that moves toward the equator, meeting with warmer air in the middle latitudes and causing rain and snow. Marine life abounds in open areas, especially the more southerly waters. The ocean's major ports are the cities of Murmansk

, Arkhangelsk

and Prudhoe Bay

.

The Arctic Ocean is encompassed by the Arctic shelves, one of which, the Siberian Shelf, is the largest on Earth.

History

For much of European history, the North Polar regions remained largely unexplored and their geography conjectural. Pytheas of Massilia recorded an account of a journey northward in 325 BCE, to a land he called "Eschate Thule," where the Sun only set for three hours each day and the water was replaced by a congealed substance "on which one can neither walk nor sail." He was probably describing loose sea ice known today as "growler", or "bergy bits." His "Thule" may have been Iceland

, though Norway

is more often suggested.

Early cartographer were unsure whether to draw the region around the North Pole as land (as in Johannes Ruysch's map of 1507, or Gerardus Mercator's map of 1595) or water (as with Martin Waldseemüller's world map of 1507). The fervent desire of European merchants for a northern passage to "Cathay" (China

) caused water to win out, and by 1723 mapmakers such as Johann Homann featured an extensive "Oceanus Septentrionalis" at the northern edge of their charts. The few expeditions to penetrate much beyond the Arctic Circle in this era added only small islands, such as Novaya Zemlya

(11th century) and Spitsbergen (1596), though since these were often surrounded by pack-ice their northern limits were not so clear. The makers of navigational chart, 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, long time Second Secretary of the British Admiralty, promoted the exploration the region from 1818 to 1845 in search of this. In the United States

in the 1850s and '60s, the explorers Elisha Kane and Isaac Israel Hayes both claimed to have seen part of this elusive body of water. Even quite late in the century, the eminent authority Matthew Fontaine Maury included a description of the Open Polar Sea in his textbook The Physical Geography of the Sea (1883). Nevertheless, as all the explorer who travelled closer and closer to the pole reported, the polar ice cap is quite thick, and persists year-round.

Fridtjof Nansen was the first to make a nautical crossing of the Arctic Ocean, in 1896. The first surface crossing of the ocean was led by Wally Herbert in 1969, in a dog sled expedition from Alaska to Svalbard

with air support.

Since 1937, Soviet and Russian manned drifting ice stations have extensively monitored the Arctic Ocean. Scientific settlements were established on the drift ice and carried thousands of kilometres by ice floes.

Climate

The images below compare the average late winter and late summer polar ice pack of the Arctic Ocean, averaged between the years 1978 and 2002, which denotes variation in amounts of ice pack during these time periods.
Extent of the Arctic ice-pack during the month of February, from 1978-2002.	Extent of the Arctic ice-pack during the month of September, from 1978-2002

Under the influence of the present ice age, the ocean is contained in a polar climate characterized by persistent cold and relatively narrow annual temperature ranges. Winters are characterized by continuous darkness (polar night), cold and stable weather conditions, and clear skies; summers are characterized by continuous daylight (midnight sun), damp and foggy weather, and weak cyclones with rain or snow.

The temperature of the surface of the Arctic Ocean is fairly constant, near the freezing point of seawater, slightly below . 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 extremes of temperature seen on the Antarctic continent

.

There is considerable seasonal variation in how much pack ice of the Arctic ice pack covers the Arctic Ocean. Much of the ocean is also covered in snow for about 10 months of the year. The maximum snow cover is in March or April — about over the frozen ocean.

Climate 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 ; the surface waters of the northernmost Arctic ocean warmed, seasonally at least, enough to support tropical lifeforms requiring surface temperatures of over .

Natural resources

Petroleum and natural gas field, placer deposits, polymetallic nodules, sand and gravel aggregate, fish, seals and whales 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 because it may hold 25% or more of the world's undiscovered oil and gas resources.

Natural hazards

Ice islands occasionally break away from northern Ellesmere Island, and icebergs are formed from glaciers in western Greenland and extreme northeastern Canada. Permafrost is found on most islands. The ocean is virtually icelocked from October to June, and ships are subject to superstructure icing from October to May. Before the advent of modern icebreakers, ships sailing the Arctic Ocean risked being trapped or crushed by sea ice (although the Baychimo drifted through the Arctic Ocean untended for decades despite these hazards).

Animal and plant life

Endangered marine species include walruses and whales. The area has a fragile ecosystem which is slow to change and slow to recover from disruptions or damage.

The Arctic Ocean has relatively little plant life except for phytoplankton. Phytoplankton are a crucial part of the ocean and there are massive amounts of them in the Arctic. Nutrients from rivers and the currents of the Atlantic and Pacific oceans provide food for the Arctic phytoplankton. During summer, the Sun is out day and night, thus enabling the phytoplankton to photosynthesize for long periods of time and reproduce quickly. However, the reverse is true in winter where they struggle to get enough light to survive.

Environmental concerns

Sea cover in the Arctic Ocean, showing the median, 2005 and 2007 coverage

Decline of summer Arctic ice from 1979-2000 to 2002-05.

The polar ice pack is thinning, and in many years there will be seasonal hole in the ozone layer.Reduction of the area of Arctic sea ice reduces the planet's average albedo, possibly resulting in global warming in a positive feedback mechanism. Research shows that the Arctic may become ice free for the first time in human history between 2013 and 2040. Many scientists are presently concerned that warming temperatures in the Arctic may cause large amounts of fresh meltwater to enter the North Atlantic, possibly disrupting global ocean current patterns. Potentially severe changes in the Earth's climate might then ensue.

Other environmental concerns relate to the radioactive contamination of the Arctic Ocean from, for example, Russian radioactive waste dump sites in the Kara Sea and Cold War nuclear test sites such as Novaya Zemlya.