The Beaufort Sea ( ; ) is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, Yukon, and Alaska, and west of the Canadian Arctic Archipelago. The sea is named after Sir Francis Beaufort, a hydrographer. The Mackenzie River, the longest in Canada, empties into the Canadian part of the Beaufort Sea west of Tuktoyaktuk, which is one of the few permanent settlements on the sea's shores.
The sea, characterized by a severe climate, is frozen over most of the year. Historically, only a narrow pass up to opened in August–September near its shores, but recently due to climate change in the Arctic the ice-free area in late summer has greatly enlarged. Until recently, the Beaufort Sea was known as an important reservoir for the replenishment of Arctic sea ice. Sea ice would often rotate for several years in the Beaufort Gyre, the dominant ocean current of the Beaufort Sea, growing into sturdy and thick multi-year ice.
Claims that the seacoast was populated about 30,000 years ago have been largely discredited (see below); present population density is very low. The sea contains significant resources of petroleum and natural gas under its shelf, such as the Amauligak field. They were discovered in the period between the 1950s and 1980s, and since the latter part of that period their exploration has become the major human activity in the area. The traditional occupations of fishing and whale and seal hunting are practiced only locally, and have no commercial significance. As a result, the sea hosts one of the largest colonies of beluga whales and, , such hunting of the species in the eastern Beaufort Sea was considered sustainable. To prevent overfishing in its waters, the US adopted a precautionary commercial fisheries management plan in August 2009.Arctic Fishery Management Plan. In April 2011, the Canadian government signed a memorandum of understanding with the Inuvialuit as a first step in developing a larger ocean management plan."Beaufort Sea Commercial Fishing Banned" (CBC News, 15 April 2011). The Canadian government announced in October 2014 that no new commercial fisheries in the Beaufort Sea will be considered until research has shown sustainable stocks that would be made available to Inuvialuit first."No new fisheries in the Arctic following federal ban"
The Canadian government designated blocks of the Beaufort Sea as Marine Protected Areas (MPAs). The Anguniaqvia niqiqyuam MPA surrounds the Parry Peninsula in the Amundsen Gulf, and the Tarium Niryutait MPA is located at the Mackenzie River delta and estuary. The protected areas are set to protect species and habitats for the Inuvialuit community.
Extent The International Hydrographic Organization defines the limits of the Beaufort Sea as follows: On the North. A line from Point Barrow, Alaska, to Lands End, Prince Patrick Island ().
On the East. From Lands End through the Southwest coast of Prince Patrick Island to Griffiths Point, thence a line to Cape Prince Alfred, the Northwestern extreme of Banks Island, through its West coast to Cape Kellet, the Southwestern point, and thence a line to Cape Bathurst on the mainland ().
Border dispute
There is an unresolved dispute involving a wedge-shaped slice on the International Boundary in the Beaufort Sea, between the Canadian territory of Yukon and the U.S. state of Alaska. Canada claims the maritime boundary to be along the 141st meridian west out to a distance of , following the Alaska–Yukon land border.The Law of the Sea Convention (BP-322E) . Dsp-psd.communication.gc.ca. Retrieved on 2013-03-21. This follows the natural prolongation principle, which holds that a nation's maritime boundary should reflect the 'natural prolongation' of where its land territory reaches the coast. The position of the United States is that the boundary line should be perpendicular to the coast out to a distance of , following a line of equidistance from the coast.Summary of claims, Department of Defense, p. 10 The equidistance principle argues that a nation's maritime boundaries should conform to a median line that is equidistant from the shores of neighbouring nations. This difference creates a wedge with an area of about that is claimed by both nations.
Canada's position has its roots in the Treaty of Saint Petersburg (1825) between the United Kingdom and the Russian Empire that set the boundary between the two. Canada is the successor state to Great Britain in relation to this treaty, which stipulates:
Canada maintains that this treaty is extensible from the land into the Beaufort Sea along the meridian. The United States rejects this extension and instead asserts a boundary line based upon equidistance, although its position is somewhat undermined by its acceptance in 1867 of similar treaty wording and a similar interpretation under the treaty whereby it acquired Alaska. Both the U.S. and Canada agree that they are bound by the 1958 Convention on the Continental Shelf; and they both agree that the boundary should be "equitable", as determined by the International Court of Justice. They differ on what should be deemed "equitable". The U.S. contends that "equidistance is an appropriate principle for determining a maritime boundary where there are no special circumstances in the area and when equidistance results in a boundary in accordance with equitable principles". Canada contends that an equidistance principle does not result in an equitable boundary, because distortion would occur. The coast of Yukon is concave, whereas the coast of Alaska is convex; and thus an equidistance principle would result in a significant extension of the U.S. possession. This dispute has taken on increased significance due to the possible presence of natural reserves within the wedge,Northern interests and Canadian foreign policy , Associate Director Centre for Military and Strategic Studies, University of CalgaryBeaufort Sea Areawide 2006, Tract Map No.8, State of Alaska Department of Natural Resources, Division of oil and gas which according to Canada's National Energy Board may contain of gas, which would cover the national consumption for 20 years, and more than of oil.US-Canada Arctic border dispute key to maritime riches, BBC News, 2 August 2010 Because of this, Canada argues that "special circumstances" apply to this border, a position that the U.S. rejects. This dispute is in this respect a mirror image of the dispute between the U.S. and Canada over the Gulf of Maine, where the U.S. argued for "special circumstances" and Canada argued for the equidistance principle. (In that latter dispute, both of those arguments were rejected, and the border was drawn based upon geometric principles taking into account geographic factors.) Neither the U.S. nor Canada has pressed for a swift resolution for the matter, or arbitration at the International Court of Justice, however; and the two have in the meantime cooperated in several measures aimed at preserving the maritime environment.
Before the end of 2004, the US leased eight plots of land below the water for oil exploration and exploitation, provoking a diplomatic protest from Canada.Sea Changes, Institute of the North On 20 August 2009, United States Secretary of Commerce Gary Locke announced a moratorium on commercial fishing of the Beaufort Sea north of Alaska, including the disputed waters. In July 2010, US–Canada negotiations have started in Ottawa with the next meeting planned in 2011. A joint geological survey of the area has been initiated, and the issue was marked as settled by the CIA World Factbook,Disputes – international: CIA – The World Factbook . Cia.gov. Retrieved on 2013-03-21. though no official document has been released by September 2010.
Moratorium on commercial fishing On August 20, 2009 United States Secretary of Commerce Gary Locke announced a moratorium on fishing the Beaufort Sea north of Alaska. According to Locke:
There is no widespread commercial fisheries in those waters now.
The moratorium was imposed in anticipation that global warming would make those waters accessible to commercial fisheries. The moratorium stirred controversy in Canada because the region where the USA announced the moratorium included a large wedge-shaped region of disputed waters. Randy Boswell, of Canada.com wrote that the disputed area covered a section of the Beaufort Sea. He wrote that Canada had filed a "diplomatic note" with the US in April when the USA first announced plans for the moratorium. Jack Layton, leader of the New Democratic Party of Canada, called the U.S. moratorium over the disputed waters in the Beaufort Sea the "largest encroachment on Canadian territory in our history."Canada, U.S. flip-flop positions in Beaufort Sea boundary dispute, Canada.com, March 8, 2010
Geography
Several rivers such as the Kongakut River in Alaska and the Firth River in Yukon empty into the Beaufort. The major river to flow into the sea is the Mackenzie, Canada's longest, which empties into the Canadian part of the sea, west of Tuktoyaktuk. The coastal shelf area is rather narrow, especially near and east of Point Barrow in the Alaskan part of the sea, and contains numerous submarine valleys. It becomes wider near the delta of the Mackenzie River but nowhere exceeds . Near the coast, the depths are shallower than but they rapidly increase northwards up to a few kilometers, transforming into a massive platform which is geologically similar to that of the oceans. There are many small islands in the sea and in the delta of the Mackenzie River. A few larger ones lie west of the Mackenzie River, such as Herschel Island ( off the shore, area ) and Barter Island ( from the coast, area ). The coasts are low, with the maximum elevations between . The soil is frozen all year around at the depth below about or less, forming permafrost, and only the top few tens of centimeters thaws in summer. Consequently, buildings have to be elevated above ground on wooden piles that are immersed into the permafrost.
Hydrology and climate
The Beaufort Sea is frozen over through the year, except for August and September when the ice breaks near the coast and opens what was once a wide strip of open water. During the 2000s, due to climate change in the Arctic, the ice-free area in late summer greatly enlarged. During the record minimum extent of Arctic sea ice in September, 2012, the sea ice boundary had retreated northward much farther than normal from the coast.
The channels of the Mackenzie River thaw earlier, in late May–early June. This thawing increases the average water discharge from about .Mackenzie River, Encyclopædia Britannica on-line
Hidden changes in the ice cover of the Beaufort Sea were discovered in 2009. Whereas the ice area remain stable, as detected by the observation satellites, so as the associated water temperature and salinity, the ice structure has changed recently. The new ice, called rotten ice, is thinner and much weaker structurally.Ice Is 'Rotten' in the Beaufort Sea, ScienceDaily, 23 January 2010
The sea water has a stable temperature and is separated into four distinct layers as follows. The top are surface water which has a temperature of in summer and in winter. The next layer is formed by the inflows from the Pacific Ocean and Bering Sea coming through the Bering Strait; it extends up to the North Pole. The warmest, deep Atlantic layer has the temperatures between , and water at the bottom is a bit colder at . The average salinity varies between 28‰ and 32‰ (parts per thousand) from south to north. Typical air temperatures (at Tuktoyaktuk) are in January and in July.Canadian Climate Normals 1971–2000. climate.weatheroffice.gc.ca