Greenland Sea

The Greenland Sea (Danish: Grønlandshavet) 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 Atlantic Ocean. However, definitions of the Arctic Ocean and its seas tend to be imprecise or arbitrary. In general usage the term "Arctic Ocean" would exclude the Greenland Sea. In oceanographic studies the Greenland Sea is considered part of the Nordic Seas, along with the Norwegian Sea. In oceanography the Arctic Ocean and Nordic Seas are often referred to collectively as the "Arctic Mediterranean Sea", a marginal sea of the Atlantic.

The sea has Arctic climate with regular northern winds and temperatures rarely rising above . It previously contained the Odden ice tongue (or Odden) area, which extended eastward from the main East Greenland ice edge in the vicinity of 72–74°N during the winter and acted as a key winter ice formation area in the Arctic. The West Ice forms in winter in the Greenland Sea, north of Iceland, between Greenland and Jan Mayen island. It is a major breeding ground of harp seal and hooded seal that has been used for seal hunting for more than 200 years.

Extent

The International Hydrographic Organization defines the limits of the Greenland Sea as follows:

On the North. A line joining the Northernmost point of Spitzbergen to the Northernmost point of Greenland.

On the East. The West coast of West Spitzbergen [island of Spitsbergen<nowiki>]</nowiki>.

On the Southeast. A line joining the Southernmost point of West Spitzbergen to the Northern point of Jan Mayen Island, down the West coast of that island to its Southern extreme, thence a Line to the Eastern extreme of Gerpir (67°05′N, 13°30′W) [sic, actually at ] in Iceland.

On the Southwest. A line joining Straumnes (NW extreme of Iceland) to Cape Nansen () in Greenland.

On the West. The East and Northeast coast of Greenland between Cape Nansen and the northernmost point.

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History

While the sea has been known for millennia,, its first scientific explorations were conducted in 1765 and 1766 as part of two Russian government expeditions under the command of Admiral V. Chichagov, who, in search of a passage north of Greenland through the Arctic, carried out oceanographic, geophysical and meteorological observations according to a special program developed by M. Lomonosov, studied currents and ice drift in the northern Greenland Sea, took soil samples, and measured depths in many places. A number of scientific investigations were carried out in 1876–1878 as part of the Norwegian North-Atlantic Expedition. Since then, many countries, mostly Norway, Iceland and Russia have sent scientific expeditions to the area. The complex water current system in the Greenland Sea was described in 1909 by Fridtjof Nansen.

The Inuit hunted whales on a non-industrial scale in the Greenland Sea since the 15th century, as evidenced by archaeology.

thumb|Sea topography

Geography and geology

right|thumb|[[Eyjafjörður, the longest fjord in Northern Iceland, belongs to the Greenland Sea.]]

The Greenland Sea is bounded to the west by the island of Greenland, and to the south by the Denmark Strait and Iceland. To the southeast, behind the Jan Mayen island (Norway) lies the vast expanse of the Norwegian Sea, of which Greenland Sea may be considered an extension. Across the Fram Strait to the northeast, the sea is delimited by the Svalbard archipelago (Norway). The southern part of the Greenland Sea, roughly the area south of the Jan Mayen Francture Zone or the line Cape Brewster – Jan Mayen is sometimes referred to as Iceland Sea.

The bottom of the Greenland Sea is a depression bounded to the south by the underwater Greenland-Iceland ridge and to the east by the Mohns Ridge and Knipovich Ridge (parts of the Mid-Atlantic Ridge). To the west, the bottom rises first slowly, but then rapidly toward the wide Greenland coastal strip. The Greenland ice sheet reaches down to the sea at Jøkel Bay.

Major islands of the Greenland Sea include the Svalbard archipelago, Jan Mayen as well as coastal islands off the NE Greenland shores, such as Hovgaard, Ella, Godfred Hansen, Île-de-France, Lynn, Norske, Gamma and Schnauder islands. Of those, only the Svalbard islands are inhabited, and Jan Mayen has only temporal military staff. After the League of Nations gave Norway jurisdiction over the island, in 1921 Norway opened the first meteorological station there, which was a subject of contention between Germany and United Kingdom during World War II. Several radio and meteorological stations operate on the island nowadays.

Hydrology, climate, and ice

thumb|A beach on Jan Mayen island

The climate is Arctic and varies significantly across the vast sea area.

Air temperatures fluctuate between near Spitsbergen in winter and off Greenland in summer. Averages are in the south and in the north in February, which is the coldest month. The corresponding values for the warmest month, August, are in the south and in the north.

Because of frequent fogs, winds, and currents, which continuously transport ice and icebergs through the Greenland Sea to the south, the Greenland Sea has a narrow window for commercial navigation: The ice season starts in October and ends in August. Three types of floating ice are distinguished: Arctic pack ice (several meters thick), sea ice (about a meter thick), and freshwater icebergs. It was discovered in the early 18th century by British whalers and since late 1750s was used for seal hunting. The hunting was especially intensive in the 19th century, but declined in the 20th century because of hunting restrictions and lower market demand. Around 5 April 1952, a major storm resulted in disappearance of ships with 79 Norwegian seal hunters on board. Seven other Norwegian seal hunting vessels shipwrecked the same month.

Odden ice tongue

thumb|Pancake ice

The Odden ice tongue or simply the Odden (Odden is Norwegian word for headland) was a key winter ice formation area in the Arctic. It was known for a long time and was encountered by Fridtjof Nansen but was only fully understood with the advent of satellite imagery.

The Odden had a length of about and covered an area of up to in most years. It extended eastward from the main East Greenland ice edge in the vicinity of 72–74°N during the winter because of the presence of very cold polar surface water in the Jan Mayen Current, which diverts some water eastward from the East Greenland Current at that latitude. Most of the already formed ice continued floating south, driven by the wind, so a cold open water surface was exposed on which new ice formed as frazil ice and pancake ice in the rough seas, producing a giant tongue shape. The salt rejected back into the ocean from this ice formation caused the surface water to become denser and sink, sometimes to great depths ( or more), making this one of the few regions of the ocean where winter convection occurred, which helped drive the entire worldwide system of surface and deep currents known as the thermohaline circulation.

Interactions with the global climate

Water from the Atlantic passes through the Greenland Sea and enters the Arctic ocean via Atlantic Meridional Overturning Circulation. The Greenland Sea is connected to these other oceans via eddies that redistribute warm water from the Atlantic Ocean and cold water from the Arctic Ocean. These eddies have been found to bring the temperature of the nearby regions of the ocean closer together, even as far away as the Indian Ocean, since 2000. These temperature changes have been linked to the slowing of water passing through the Greenland Sea from the Atlantic and Arctic oceans, however it is unclear how this flow might change in the future. This warming has also been linked to an increase in rains and monsoon intensity in India. Reduction of sea ice in the Greenland Sea has been linked to increased volumes of precipitation that forms in the ocean around both India and Korea, precipitation intensity on Svalbard, and to temperature instability during summer in European Russia. Some of this melting is due to warming foehn winds from the northeast.

Fauna

The Greenland Sea is densely inhabited by the organisms that form the base of the oceanic food chain. Large invertebrates, fish (such as cod, herring, redfish, halibut, and plaice), birds, and mammals (including various species of seals, whales, and dolphins) all feed on the smaller invertebrates and small organisms. Mosses, lichens, and scanty bushes around the coasts serve as food to the deer and musk oxen, which in turn are hunted by the polar bear. This has led the Greenland's minister and provincial council to offer a large number of off-shore concessions to potential hydrocarbon (oil and gas) extraction. The majority of the concessions are located in seas west of Greenland (primarily the Davis Strait and Baffin Bay), but with 19 concessions in the Greenland Sea.

In late 2013, a total of three consortia obtained hydrocarbon extraction rights to four large areas of the Greenland Sea from the Greenland Bureau of Mineral and Petroleum. The consortia are led by the oil companies of Statoil, Chevron, and Eni, but includes several other smaller companies such as Shell, BP, DONG Energy and Nunaoil. Since then, a fifth hydrocarbon concession has been sold. ExxonMobil, the largest oil company in the world and with a lot of experience in the Arctic, was also applying for oil extraction rights in the Greenland Sea initially, but pulled out in December 2013 for unexplained reasons, concentrating efforts on shale gas and the American market instead.

The Greenland Minister Council expected the first exploratory drills to take place some time in the 2020s.