خلیج هادسِن (به انگلیسی: Hudson Bay) یکی از بزرگترین خلیجهای دنیا است است که در کانادا واقع است. این خلیج از اطراف به ایالات: نوناووت، مانیتوبا، انتاریو و کبک محصور شدهاست. این خلیج به وسیله تنگه هادسون به دریای لابرادور راه دارد. در این خلیج جزایر زیادی وجود دارد که از مهمترین آنان: جزایر اتاوا، جزیره کوتس، جزایر بلچر، جزیره ماسل و جزیره آکیمیسکی را میتوان نام برد.
عمق میانگین این خلیج ۱۰۰m و حداکثر عمق آن ۲۷۰m است.
The Eastern Cree name for Hudson and James Bay is Wînipekw (Southern dialect) or Wînipâkw (Northern dialect), meaning muddy or brackish water. Lake Winnipeg is similarly named by the local Cree, as is the location for the city of Winnipeg.
Hudson Bay is often considered part of the Arctic Ocean; the International Hydrographic Organization, in its 2002 working draft of Limits of Oceans and Seas) defined the Hudson Bay, with its outlet extending from 62.5 to 66.5 degrees north (just a few miles south of the Arctic Circle) as being part of the Arctic Ocean, specifically "Arctic Ocean Subdivision 9.11." Other authorities include it in the Atlantic, in part because of its greater water budget connection with that ocean.
Some sources describe Hudson Bay as a marginal sea of the Atlantic Ocean, or the Arctic Ocean.
Canada treats the bay as an internal body of water and has claimed it as such on historic grounds. This claim is disputed by the United States but no action to resolve it has been taken.
Canada, routes of explorers, 1497 to 1905
English explorers and colonists named Hudson Bay after Sir Henry Hudson who explored the bay beginning August 2, 1610 on his ship Discovery.:170 On his fourth voyage to North America, Hudson worked his way around Greenland's west coast and into the bay, mapping much of its eastern coast. Discovery became trapped in the ice over the winter, and the crew survived onshore at the southern tip of James Bay. When the ice cleared in the spring, Hudson wanted to explore the rest of the area, but the crew mutinied on June 22, 1611. They left Hudson and others adrift in a small boat. No one knows the fate of Hudson or the crew members stranded with him, but historians see no evidence that they survived for long afterwards.:185
HBC's trade monopoly was abolished in 1870, and it ceded Rupert's Land to Canada, an area of approximately 3,900,000 km2 (1,500,000 sq mi), as part of the Northwest Territories.:427 Starting in 1913, the Bay was extensively charted by the Canadian Government's CSS Acadia to develop it for navigation. This mapping progress led to the establishment of Churchill, Manitoba as a deep-sea port for wheat exports in 1929, after unsuccessful attempts at Port Nelson.
Polar bear walks on newly formed ice in early November at Hudson Bay.
Northern Hudson Bay has a polar climate (Köppen: ET) being one of the few places in the world where this type of climate is found south of 60 °N, going further south towards Quebec, where Inukjuak is still dominated by the tundra. From Arviat, Nunavut to the west to the south and southeast prevails the subarctic climate (Köppen: Dfc). This is because in the central summer months, heat waves can advance and leave the weather cool, where the average temperature of the month is above 10 °C. At the southern end in the extension known as James Bay arises the humid continental climate with a more pronounced and hot summer. (Köppen: Dfb) The average annual temperature in almost the entire bay is around 0 °C (32 °F) or below. Except for the James Bay area the average water temperature is only 7 °C (45 °F) to the south in January. Although the difference is small in summer in the extreme northeast, wintery temperatures are four to five degrees colder coming near −27 °C (−17 °F).
The Hudson Bay region has very low year-round average temperatures. The average annual temperature for Churchill at 59°N is −5 °C (23 °F) and Inukjuak facing cool westerlies in summer at 58°N an even colder −7 °C (19 °F); by comparison Arkhangelsk at 64°N with a similar subarctic climate in northern Russia has an average of 2 °C (36 °F).) and the mild continental coastline of Stockholm at 59°N at near 8 °C (46 °F) on the seashore of a similar inlet major body of water; the Baltic Sea. Water temperature peaks at 8–9 °C (46–48 °F) on the western side of the bay in late summer. It is largely frozen over from mid-December to mid-June when it usually clears from its eastern end westwards and southwards. A steady increase in regional temperatures over the last 100 years has been reflected in a lengthening of the ice-free period which was as short as four months in the late 17th century.
In late spring (May), large chunks of ice float near the eastern shore of the bay, while the center of the bay remains frozen to the west. Between 1971 and 2007, the length of the ice-free season increased by about seven days in the southwestern part of the Hudson Bay, historically the last area to thaw.
Hudson Bay has a lower average salinity level than that of ocean water. The main causes are the low rate of evaporation (the bay is ice-covered for much of the year), the large volume of terrestrial runoff entering the bay (about 700 km3 (170 cu mi) annually, the Hudson Bay watershed covering much of Canada, many rivers and streams discharging into the bay), and the limited connection with the Atlantic Ocean and its higher salinity. Sea ice is about three times the annual river flow into the bay, and its annual freezing and thawing significantly alters the salinity of the surface layer.
One consequence of the lower salinity of the bay is that the freezing point of the water is higher than in the rest of the world's oceans, thus decreasing the time that the bay remains ice-free.
The western shores of the bay are a lowland known as the Hudson Bay Lowlands which covers 324,000 km2 (125,000 sq mi). The area is drained by a large number of rivers and has formed a characteristic vegetation known as muskeg. Much of the landform has been shaped by the actions of glaciers and the shrinkage of the bay over long periods of time. Signs of numerous former beachfronts can be seen far inland from the current shore. A large portion of the lowlands in the province of Ontario is part of the Polar Bear Provincial Park, and a similar portion of the lowlands in Manitoba is contained in Wapusk National Park, the latter location being a significant polar bearmaternity denning area.
In contrast, most of the eastern shores (the Quebec portion) form the western edge of the Canadian Shield in Quebec. The area is rocky and hilly. Its vegetation is typically boreal forest, and to the north, tundra.
Measured by shoreline, Hudson Bay is the largest bay in the world (the largest in area being the Bay of Bengal).
There are many islands in Hudson Bay, mostly near the eastern coast. All, as are the islands in James Bay, are part of Nunavut and lie in the Arctic Archipelago. Several are disputed by the Cree. One group of islands is the Belcher Islands. Another group includes the Ottawa Islands.
From the large quantity of published geologic data that has been collected as the result of hydrocarbon exploration, academic research, and related geologic mapping, a detailed history of the Hudson Bay basin has been reconstructed. During the majority of the Cambrian Period, this basin did not exist. Rather, this part of the Canadian Shield area was still topographically high and emergent. It was only during the later part of the Cambrian that the rising sea level of the Saukmarine transgression slowly submerged it. During the Ordovician, this part of the Canadian Shield continued to be submerged by rising sea levels except for a brief middle Ordovician marine regression. Only starting in the Late Ordovician and continuing into the Silurian did the gradual regional subsidence of this part of the Canadian Shield form the Hudson Bay basin. The formation of this basin resulted in the accumulation of black bituminousoil shale and evaporite deposits within its centre, thick basin-margin limestone and dolomite, and the development of extensive reefs that ringed the basin margins that were tectonically uplifted as the basin subsided. During Middle Silurian times, subsidence ceased and this basin was uplifted. It generated an emergent arch, on which reefs grew, that divided the basin into eastern and western sub-basins. During the Devonian Period, this basin filled with terrestrial red beds that interfinger with marine limestone and dolomites. Before deposition was terminated by marine regression, Upper Devonian black bituminous shale accumulated in the south-east of the basin.
The remaining history of the Hudson Bay basin is largely unknown as a major unconformity separates Upper Devonian strata from glacial deposits of the Pleistocene. Except for poorly known terrestrial Cretaceous fluvial sands and gravels that are preserved as the fills of a ring of sinkholes around the centre of this basin, strata representing this period of time are absent from the Hudson Bay basin and the surrounding Canadian Shield.
The Precambrian Shield underlying Hudson Bay and in which Hudson Bay basin formed is composed of two Archean proto-continents, the Western Churchill and Superior cratons. These cratons are separated by a tectonic collage that forms a suture zone between these cratons and the Trans-Hudson Orogen. The Western Churchill and Superior cratons collided at about 1.9–1.8 Ga in the Trans-Hudson orogeny. Because of the irregular shapes of the colliding cratons, this collision trapped between them large fragments of juvenile crust, a sizable microcontinent, and island arcterranes, beneath what is now the centre of modern Hudson Bay as part of the Trans-Hudson Orogen. The Belcher Islands are the eroded surface of the Belcher Fold Belt, which formed as a result of the tectonic compression and folding of sediments that accumulated along the margin of the Superior Craton before its collision with the Western Churchill Craton.
Map of post-glacial rebound. Hudson Bay is in the region of the most rapid uplift.
Hudson Bay and the associated structural basin lies within the centre of a large free-air gravity anomaly that lies within the Canadian Shield. The similarity in areal extent of the free-air gravity anomaly with the perimeter of the former Laurentide Ice Sheet that covered this part of Laurentia led to a long-held conclusion that this perturbation in the Earth’s gravity reflected still ongoing glacial isostatic adjustment to the melting and disappearance of this ice sheet. Data collected over Canada by the Gravity Recovery and Climate Experiment (GRACE) satellite mission allowed geophysicists to isolate the gravity signal associated with glacial isostatic adjustment from longer–time scale process of mantle convection occurring beneath the Canadian Shield. Based upon this data, geophysicists and other Earth scientists concluded that the Laurentide Ice Sheet was composed of two large domes to the west and east of Hudson Bay. Modeling glacial isostatic adjustment using the GRACE data, they concluded that ~25 to ~45% of the observed free-air gravity anomaly was due to ongoing glacial isostatic adjustment, and the remainder likely represents longer time-scale effects of mantle convection.
Earth scientists have disagreed about what created the semicircular feature known as the Nastapoka arc that forms a section of the shoreline of southeastern Hudson Bay. Noting the paucity of impact structures on Earth in relation to the Moon and Mars, Carlyle Smith Beals proposed that it is possibly part of a Precambrian extraterrestrial impact structure that is comparable in size to the Mare Crisium on the Moon. In the same volume, John Tuzo Wilson commented on Beals' interpretation and alternately proposed that the Nastapoka arc may have formed as part of an extensive Precambrian continental collisional orogen, linked to the closure of an ancient ocean basin. The current general consensus is that it is an arcuate boundary of tectonic origin between the Belcher Fold Belt and undeformed basement of the Superior Craton created during the Trans-Hudson orogeny. This is because no credible evidence for such an impact structure has been found by regional magnetic, Bouguer gravity, and other geologic studies. However, other Earth scientists have proposed that the evidence of an Archean impact might have been masked by deformation accompanying the later formation of the Trans-Hudson orogen and regard an impact origin as a plausible possibility.
The Arctic Bridge shipping route (blue line) is hoped to link North America to markets in Europe and Asia using ice-free routes across the Arctic Ocean
The longer periods of ice-free navigation and the reduction of Arctic Ocean ice coverage have led to Russian and Canadian interest in the potential for commercial trade routes across the Arctic and into Hudson Bay. The so-called Arctic Bridge would link Churchill, Manitoba, and the Russian port of Murmansk.
The coast of Hudson Bay is extremely sparsely populated; there are only about a dozen communities. Some of these were founded as trading posts in the 17th and 18th centuries by the Hudson's Bay Company, making them some of the oldest settlements in Western Canada. With the closure of the HBC posts and stores, although many are now run by The North West Company, in the second half of the 20th century, many coastal villages are now almost exclusively populated by Cree and Inuit people. Two main historic sites along the coast were York Factory and Prince of Wales Fort.
Communities along the Hudson Bay coast or on islands in the bay are (all populations are as of 2016):
The Hudson's Bay Company built forts as fur trade strongholds against the French or other possible invaders. One example is York Factory with angled walls to help defend the fort. In the 1950s, during the Cold War, a few sites along the coast became part of the Mid-Canada Line, watching for a potential Soviet bomber attack over the North Pole. The only Arctic deep-water port in Canada is the Port of Churchill, located at Churchill, Manitoba.
^ abcBurgess, P.M., 2008, Phanerozoic evolution of the sedimentary cover of the North American craton., in Miall, A.D., ed., Sedimentary Basins of the United States and Canada, Elsevier Science, Amsterdam, pp. 31–63.
^ abcLavoie, D., Pinet, N., Dietrich, J. and Chen, Z., 2015. The Paleozoic Hudson Bay Basin in northern Canada: New insights into hydrocarbon potential of a frontier intracratonic basin.American Association of Petroleum Geologists Bulletin, 99(5), pp. 859–888.
^ abRoksandic, M.M., 1987, The tectonics and evolution of the Hudson Bay region, in C. Beaumont and A. J. Tankard, eds., Sedimentary basins and basin-forming mechanisms. Canadian Society of Petroleum Geologists Memoir 12, p. 507–518.
^ abcSanford, B.V. and Grant, A.C., 1998. Paleozoic and Mesozoic geology of the Hudson and southeast Arctic platforms.Geological Survey of Canada Open File 3595, scale 1:2 500 000.
^ abDarbyshire, F.A., and Eaton, D.W., 2010. The lithospheric root beneath Hudson Bay, Canada from Rayleigh wave dispersion: No clear seismological distinction between Archean and Proterozoic mantle, Lithos. 120(1-2), 144–159, doi:10.1016/j.lithos.2010.04.010.
^ abEaton, D.W., and Darbyshire, F., 2010. Lithospheric architecture and tectonic evolution of the Hudson Bay region, Tectonophysics. 480(1-4), 1–22, doi:10.1016/j.tecto.2009.09.006.
^Tamisiea, M.E., Mitrovica, J.X. and Davis, J.L., 2007. GRACE gravity data constrain ancient ice geometries and continental dynamics over Laurentia. Science, 316(5826), pp. 881–883.
^Beals, C.S., 1968. On the possibility of a catastrophic origin for the great arc of eastern Hudson Bay. In: Beals, C.S. (Ed.), pp. 985–999. Science, History and Hudson Bay, Vol. 2, Department of Energy Mines and Resources, Ottawa.
^Wilson, J.T., 1968. Comparison of the Hudson Bay arc with some other features. In: Beals, C.S. (Ed.), pp. 1015–1033. Science, History and Hudson Bay, Vol. 2. Department of Energy Mines and Resources, Ottawa.
^Goodings, C.R. & Brookfield, M.E., 1992. Proterozoic transcurrent movements along the Kapuskasing lineament (Superior Province, Canada) and their relationship to surrounding structures.Earth-Science Reviews, 32: 147–185.
^Bleeker, W., and Pilkington, M., 2004. The 450-km-diameter Nastapoka Arc: Earth's oldest and largest preserved impact scar?Program with Abstracts – Geological Association of Canada; Mineralogical Association of Canada: Joint Annual Meeting, 2004, Vol. 29, pp. 344.