82-742: Grays Bay is an Arctic waterway in the Kitikmeot Region , Nunavut , Canada. It is located in Coronation Gulf and Hepburn Island is located at its mouth. The Tree River and the Annielik River flow into the bay. It is the ancestral home of the Kogluktuaryumiut , a Copper Inuit subgroup. Grays Bay is on the Northwest Passage route. Grays Bay was proposed as the site of a potential dock facility. In 2007 Wolfden Resources received
164-684: A Russian flag made of rust-proof titanium alloy . The flag-placing, during Arktika 2007 , generated commentary on and concern for a race for control of the Arctic's vast hydrocarbon resources. Foreign ministers and other officials representing Canada, the Kingdom of Denmark, Norway, Russia, and the United States met in Ilulissat, Greenland on 28 May 2008 at the Arctic Ocean Conference and announced
246-502: A ring species exists and has been described around the Arctic Circle in the form of the Larus gulls. There are copious natural resources in the Arctic (oil, gas, minerals, fresh water, fish and, if the subarctic is included, forest) to which modern technology and the economic opening up of Russia have given significant new opportunities. The interest of the tourism industry is also on
328-475: A shear zone , a marginal ice zone and a central pack . Drift ice consists of floes , individual pieces of sea ice 20 metres (66 ft) or more across. There are names for various floe sizes: small – 20 to 100 m (66 to 328 ft); medium – 100 to 500 m (330 to 1,640 ft); big – 500 to 2,000 m (1,600 to 6,600 ft); vast – 2 to 10 kilometres (1.2 to 6.2 mi); and giant – more than 10 km (6.2 mi). The term pack ice
410-430: A beach with a light swell, ice eggs up to the size of a football can be created. Nilas designates a sea ice crust up to 10 centimetres (3.9 in) in thickness. It bends without breaking around waves and swells. Nilas can be further subdivided into dark nilas – up to 5 cm (2.0 in) in thickness and very dark and light nilas – over 5 cm (2.0 in) in thickness and lighter in color. Young ice
492-445: A certain point such a disc shape becomes unstable and the growing isolated crystals take on a hexagonal, stellar form, with long fragile arms stretching out over the surface. These crystals also have their c-axis vertical. The dendritic arms are very fragile and soon break off, leaving a mixture of discs and arm fragments. With any kind of turbulence in the water, these fragments break up further into random-shaped small crystals which form
574-629: A favourable review "for its copper/zinc mine proposal from the Nunavut Impact Review Board (NIRB)." The proposal included plans for a 53 km (33 mi) all-weather road that would include a dock facility at Grays Bay on the Coronation Gulf , and will parallel the Kennartic River to the mine site at High Lake." MMG Minerals (Minerals and Metals Group), a subsidiary of the Chinese state-owned Minmetals Resources Ltd., has also proposed
656-558: A much more reliable measure of long-term changes in sea ice. In comparison to the extended record, the sea-ice extent in the polar region by September 2007 was only half the recorded mass that had been estimated to exist within the 1950–1970 period. Arctic sea ice extent ice hit an all-time low in September 2012, when the ice was determined to cover only 24% of the Arctic Ocean, offsetting the previous low of 29% in 2007. Predictions of when
738-540: A number of definitions of what area is contained within the Arctic. The area can be defined as north of the Arctic Circle (about 66° 34'N), the approximate southern limit of the midnight sun and the polar night . Another definition of the Arctic, which is popular with ecologists , is the region in the Northern Hemisphere where the average temperature for the warmest month (July) is below 10 °C (50 °F);
820-499: A port "that could accommodate ships of up to 50,000 tonnes that would make 16 round trips a year — both east and west —through the Northwest Passage" and a "350-kilometre all-weather road with 70 bridges that would stretch from Izok Lake to Grays Bay." The multibillion-dollar Izok Corridor project is projected to produce 180,000 tonnes of zinc and another 50,000 tonnes of copper a year. In order to do this "Izok Lake would be drained,
902-633: A process called congelation growth. This growth process yields first-year ice. In rough water, fresh sea ice is formed by the cooling of the ocean as heat is lost into the atmosphere. The uppermost layer of the ocean is supercooled to slightly below the freezing point, at which time tiny ice platelets (frazil ice) form. With time, this process leads to a mushy surface layer, known as grease ice . Frazil ice formation may also be started by snowfall , rather than supercooling. Waves and wind then act to compress these ice particles into larger plates, of several meters in diameter, called pancake ice . These float on
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#1732869771786984-475: A standard protocol for studying the output of coupled atmosphere-ocean general circulation models. The coupling takes place at the atmosphere-ocean interface where the sea ice may occur. In addition to global modeling, various regional models deal with sea ice. Regional models are employed for seasonal forecasting experiments and for process studies . Sea ice is part of the Earth's biosphere . When sea water freezes,
1066-442: A state of shear . Sea ice deformation results from the interaction between ice floes, as they are driven against each other. The result may be of three types of features: 1) Rafted ice , when one piece is overriding another; 2) Pressure ridges , a line of broken ice forced downward (to make up the keel ) and upward (to make the sail ); and 3) Hummock , a hillock of broken ice that forms an uneven surface. A shear ridge
1148-421: A suspension of increasing density in the surface water, an ice type called frazil or grease ice . In quiet conditions the frazil crystals soon freeze together to form a continuous thin sheet of young ice; in its early stages, when it is still transparent – that is the ice called nilas . Once nilas has formed, a quite different growth process occurs, in which water freezes on to the bottom of the existing ice sheet,
1230-493: Is a polar region located at the northernmost part of Earth. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( Nordland , Troms , Finnmark , Svalbard and Jan Mayen ), northernmost Sweden ( Västerbotten , Norrbotten and Lappland ), northern Finland ( North Ostrobothnia , Kainuu and Lappi ), Russia ( Murmansk , Siberia , Nenets Okrug , Novaya Zemlya ),
1312-422: Is a general term used for recently frozen sea water that does not yet make up solid ice. It may consist of frazil ice (plates or spicules of ice suspended in water), slush (water saturated snow), or shuga (spongy white ice lumps a few centimeters across). Other terms, such as grease ice and pancake ice , are used for ice crystal accumulations under the action of wind and waves. When sea ice begins to form on
1394-462: Is a large variance in predictions of Arctic sea ice loss, with models showing near-complete to complete loss in September from 2035 to some time around 2067. Arctic life is characterized by adaptation to short growing seasons with long periods of sunlight, and cold, dark, snow-covered winter conditions. Arctic vegetation is composed of plants such as dwarf shrubs , graminoids , herbs , lichens , and mosses , which all grow relatively close to
1476-464: Is a pressure ridge that formed under shear – it tends to be more linear than a ridge induced only by compression. A new ridge is a recent feature – it is sharp-crested, with its side sloping at an angle exceeding 40 degrees. In contrast, a weathered ridge is one with a rounded crest and with sides sloping at less than 40 degrees. Stamukhi are yet another type of pile-up but these are grounded and are therefore relatively stationary. They result from
1558-447: Is a significant source of errors in sea-ice thickness retrieval using radar and laser satellite altimetry, resulting in uncertainties of 0.3–0.4 m. Changes in sea ice conditions are best demonstrated by the rate of melting over time. A composite record of Arctic ice demonstrates that the floes' retreat began around 1900, experiencing more rapid melting beginning within the past 50 years. Satellite study of sea ice began in 1979 and became
1640-465: Is a transition stage between nilas and first-year ice and ranges in thickness from 10 cm (3.9 in) to 30 cm (12 in), Young ice can be further subdivided into grey ice – 10 cm (3.9 in) to 15 cm (5.9 in) in thickness and grey-white ice – 15 cm (5.9 in) to 30 cm (12 in) in thickness. Young ice is not as flexible as nilas, but tends to break under wave action. Under compression, it will either raft (at
1722-512: Is a unique area among Earth's ecosystems. The cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions. Life in the Arctic includes zooplankton and phytoplankton , fish and marine mammals , birds, land animals, plants and human societies. Arctic land is bordered by the subarctic . The word Arctic comes from the Greek word ἀρκτικός ( arktikos ), "near
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#17328697717861804-651: Is also claiming a large swath of seabed along the Lomonosov Ridge but, unlike Denmark, confined its claim to its side of the Arctic region. In August 2015, Russia made a supplementary submission for the expansion of the external borders of its continental shelf in the Arctic Ocean , asserting that the eastern part of the Lomonosov Ridge and the Mendeleyev Ridge are an extension of the Eurasian continent. In August 2016,
1886-432: Is also a concern. Because of the amplified response of the Arctic to global warming, it is often seen as a leading indicator of global warming. The melting of Greenland's ice sheet is linked to polar amplification. The Arctic region is especially vulnerable to the effects of any climate change , as has become apparent with the reduction of sea ice in recent years. Climate models predict much greater climate change in
1968-419: Is also predicted to have a large impact on tundra vegetation, causing an increase of shrubs, and having a negative impact on bryophytes and lichens. Apart from concerns regarding the detrimental effects of warming in the Arctic, some potential opportunities have gained attention. The melting of the ice is making the Northwest Passage , shipping routes through the northernmost latitudes, more navigable, raising
2050-459: Is attached (or frozen) to the shoreline (or between shoals or to grounded icebergs ). If attached, it is called landfast ice, or more often, fast ice (as in fastened ). Alternatively and unlike fast ice, drift ice occurs further offshore in very wide areas and encompasses ice that is free to move with currents and winds. The physical boundary between fast ice and drift ice is the fast ice boundary . The drift ice zone may be further divided into
2132-518: Is particularly common around Antarctica . Russian scientist Vladimir Vize (1886–1954) devoted his life to study the Arctic ice pack and developed the Scientific Prediction of Ice Conditions Theory , for which he was widely acclaimed in academic circles. He applied this theory in the field in the Kara Sea , which led to the discovery of Vize Island . The annual freeze and melt cycle is set by
2214-401: Is sea ice that has survived at least one melting season ( i.e. one summer). For this reason, this ice is generally thicker than first-year sea ice. Old ice is commonly divided into two types: second-year ice , which has survived one melting season and multiyear ice , which has survived more than one. (In some sources, old ice is more than two years old.) Multi-year ice is much more common in
2296-707: Is subject to some regulatory control through the International Code for Ships Operating in Polar Waters , adopted by the International Maritime Organization on 1 January 2017 and applies to all ships in Arctic waters over 500 tonnes. Research in the Arctic has long been a collaborative international effort, evidenced by the International Polar Year . The International Arctic Science Committee , hundreds of scientists and specialists of
2378-518: Is the main driving force, along with ocean currents. The Coriolis force and sea ice surface tilt have also been invoked. These driving forces induce a state of stress within the drift ice zone. An ice floe converging toward another and pushing against it will generate a state of compression at the boundary between both. The ice cover may also undergo a state of tension , resulting in divergence and fissure opening. If two floes drift sideways past each other while remaining in contact, this will create
2460-426: Is used either as a synonym to drift ice , or to designate drift ice zone in which the floes are densely packed. The overall sea ice cover is termed the ice canopy from the perspective of submarine navigation. Another classification used by scientists to describe sea ice is based on age, that is, on its development stages. These stages are: new ice , nilas , young ice , first-year and old . New ice
2542-591: The Muttaburrasaurus of Australia. However, others claim that dinosaurs lived year-round at very high latitudes, such as near the Colville River , which is now at about 70° N but at the time (70 million years ago) was 10° further north. The earliest inhabitants of North America's central and eastern Arctic are referred to as the Arctic small tool tradition (AST) and existed c. 2500 BCE . AST consisted of several Paleo-Eskimo cultures, including
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2624-553: The Arctic than it is in the Antarctic . The thickness of old sea ice typically ranges from 2 to 4 m. The reason for this is that sea ice in the south drifts into warmer waters where it melts. In the Arctic, much of the sea ice is land-locked. While fast ice is relatively stable (because it is attached to the shoreline or the seabed), drift (or pack) ice undergoes relatively complex deformation processes that ultimately give rise to sea ice's typically wide variety of landscapes. Wind
2706-613: The Arctic Council , and the Barents Euro-Arctic Council are more examples of collaborative international Arctic research. While there are several ongoing territorial claims in the Arctic , no country owns the geographic North Pole or the region of the Arctic Ocean surrounding it. The surrounding six Arctic states that border the Arctic Ocean—Canada, Kingdom of Denmark (with Greenland), Iceland, Norway, Russia, and
2788-545: The Arctic Ocean and the Antarctic ice pack of the Southern Ocean . Polar packs undergo a significant yearly cycling in surface extent, a natural process upon which depends the Arctic ecology , including the ocean's ecosystems . Due to the action of winds, currents and temperature fluctuations, sea ice is very dynamic, leading to a wide variety of ice types and features. Sea ice may be contrasted with icebergs , which are chunks of ice shelves or glaciers that calve into
2870-667: The Arctic poppy ). Herbivores on the tundra include the Arctic hare , lemming , muskox , and reindeer (caribou). They are preyed on by the snowy owl , Arctic fox , grizzly bear , and Arctic wolf . The polar bear is also a predator, though it prefers to hunt for marine life from the ice. There are also many birds and marine species endemic to the colder regions. Other terrestrial animals include wolverines , moose , Dall sheep , ermines , and Arctic ground squirrels . Marine mammals include seals , walruses , and several species of cetacean — baleen whales and also narwhals , orcas , and belugas . An excellent and famous example of
2952-605: The Ilulissat Declaration , blocking any "new comprehensive international legal regime to govern the Arctic Ocean," and pledging "the orderly settlement of any possible overlapping claims." As of 2012, the Kingdom of Denmark is claiming the continental shelf based on the Lomonosov Ridge between Greenland and over the North Pole to the northern limit of the exclusive economic zone of Russia . The Russian Federation
3034-603: The Independence cultures and Pre-Dorset culture. The Dorset culture ( Inuktitut : Tuniit or Tunit ) refers to the next inhabitants of central and eastern Arctic. The Dorset culture evolved because of technological and economic changes during the period of 1050–550 BCE. With the exception of the Quebec / Labrador peninsula, the Dorset culture vanished around 1500 CE. Supported by genetic testing , evidence shows that descendants of
3116-825: The UN Commission on the Limits of the Continental Shelf began to consider Russia's submission. Canada claims the Northwest Passage as part of its internal waters belonging to Canada, while the United States and most maritime nations regards it as an international strait , which means that foreign vessels have right of transit passage. Since 1937, the larger portion of the Asian-side Arctic region has been extensively explored by Soviet and Russian crewed drifting ice stations . Between 1937 and 1991, 88 international polar crews established and occupied scientific settlements on
3198-541: The United Nations Conference on Sustainable Development , on 21 June 2012, proposed protecting the Arctic, similar to the Antarctic Treaty System . The initial focus of the campaign will be a UN resolution creating a global sanctuary around the pole, and a ban on oil drilling and unsustainable fishing in the Arctic. The Arctic has climate change rates that are amongst the highest in the world. Due to
3280-430: The drift ice and were carried thousands of kilometres by the ice flow. The Arctic is comparatively clean, although there are certain ecologically difficult localized pollution problems that present a serious threat to people's health living around these pollution sources. Due to the prevailing worldwide sea and air currents, the Arctic area is the fallout region for long-range transport pollutants , and in some places
3362-525: The ice dynamics and the thermodynamical properties (see Sea ice emissivity modelling , Sea ice growth processes and Sea ice thickness ). There are many sea ice model computer codes available for doing this, including the CICE numerical suite . Many global climate models (GCMs) have sea ice implemented in their numerical simulation scheme in order to capture the ice–albedo feedback correctly. Examples include: The Coupled Model Intercomparison Project offers
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3444-448: The ocean surface and collide with one another, forming upturned edges. In time, the pancake ice plates may themselves be rafted over one another or frozen together into a more solid ice cover, known as consolidated pancake ice. Such ice has a very rough appearance on top and bottom. If sufficient snow falls on sea ice to depress the freeboard below sea level, sea water will flow in and a layer of ice will form of mixed snow/sea water. This
3526-424: The permafrost thaws. The melting of Greenland's ice sheet is linked to polar amplification . Due to the poleward migration of the planet's isotherms (about 56 km (35 mi) per decade during the past 30 years as a consequence of global warming), the Arctic region (as defined by tree line and temperature) is currently shrinking. Perhaps the most alarming result of this is Arctic sea ice shrinkage. There
3608-680: The Arctic than the global average, resulting in significant international attention to the region. In particular, there are concerns that Arctic shrinkage, a consequence of melting glaciers and other ice in Greenland, could soon contribute to a substantial rise in sea levels worldwide. The current Arctic warming is leading to ancient carbon being released from thawing permafrost , leading to methane and carbon dioxide production by micro-organisms. Release of methane and carbon dioxide stored in permafrost could cause abrupt and severe global warming, as they are potent greenhouse gases . Climate change
3690-469: The Bear, northern" and from the word ἄρκτος ( arktos ), meaning bear. The name refers either to the constellation known as Ursa Major , the "Great Bear", which is prominent in the northern portion of the celestial sphere , or to the constellation Ursa Minor , the "Little Bear", which contains the celestial north pole (currently very near Polaris , the current north Pole Star, or North Star). There are
3772-591: The Dorset culture, known as the Sadlermiut , survived in Aivilik, Southampton and Coats Islands , until the beginning of the 20th century. The Dorset / Thule culture transition dates around the ninth–10th centuries CE. Scientists theorize that there may have been cross-contact of the two cultures with sharing of technology, such as fashioning harpoon heads, or the Thule may have found Dorset remnants and adapted their ways with
3854-517: The Dorset people in "an example of prehistoric genocide." By 1300 CE, the Inuit , present-day Arctic inhabitants and descendants of Thule culture, had settled in west Greenland, and moved into east Greenland over the following century ( Inughuit , Kalaallit and Tunumiit are modern Greenlandic Inuit groups descended from Thule). Over time, the Inuit have migrated throughout the Arctic regions of Eastern Russia,
3936-448: The Earth's temperature gets warmer. Furthermore, the sea ice itself functions to help keep polar climates cool, since the ice exists in expansive enough amounts to maintain a cold environment. At this, sea ice's relationship with global warming is cyclical; the ice helps to maintain cool climates, but as the global temperature increases, the ice melts and is less effective in keeping those climates cold. The bright, shiny surface ( albedo ) of
4018-523: The North , and Saami Council ). The council operates on consensus basis, mostly dealing with environmental treaties and not addressing boundary or resource disputes. Though Arctic policy priorities differ , every Arctic nation is concerned about sovereignty/defense, resource development, shipping routes, and environmental protection. Much work remains on regulatory agreements regarding shipping, tourism, and resource development in Arctic waters. Arctic shipping
4100-553: The Project." The Grays Bay port would be open three months of the year to "ship ore in two directions through both ends of the Northwest Passage." The project was revived in 2024, with permitting anticipated to take until 2027, and construction to begin in 2030. This Kitikmeot Region , Nunavut location article is a stub . You can help Misplaced Pages by expanding it . Arctic The Arctic ( / ˈ ɑːr k t ɪ k / or / ˈ ɑːr t ɪ k / ) (from Greek ἄρκτος, 'bear')
4182-422: The United States ( Alaska ), Canada ( Yukon , Northwest Territories , Nunavut ), Danish Realm ( Greenland ), and northern Iceland ( Grímsey and Kolbeinsey ), along with the Arctic Ocean and adjacent seas. Land within the Arctic region has seasonally varying snow and ice cover, with predominantly treeless permafrost under the tundra . Arctic seas contain seasonal sea ice in many places. The Arctic region
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#17328697717864264-744: The United States, Canada, and Greenland. Other Circumpolar North indigenous peoples include the Chukchi , Evenks , Iñupiat , Khanty , Koryaks , Nenets , Sámi , Yukaghir , Gwichʼin , and Yupik . The eight Arctic nations (Canada, Kingdom of Denmark [Greenland & The Faroe Islands], Finland, Iceland, Norway, Sweden, Russia, and US) are all members of the Arctic Council , as are organizations representing six indigenous populations (The Aleut International Association , Arctic Athabaskan Council , Gwich'in Council International , Inuit Circumpolar Council , Russian Association of Indigenous Peoples of
4346-662: The United States—are limited to a 200 nautical miles (370 km; 230 mi) exclusive economic zone (EEZ) off their coasts. Two Arctic states (Finland and Sweden) do not have direct access to the Arctic Ocean. Upon ratification of the United Nations Convention on the Law of the Sea , a country has ten years to make claims to an extended continental shelf beyond its 200 nautical mile zone. Due to this, Norway (which ratified
4428-435: The amount of melting ice. Though the size of the ice floes is affected by the seasons, even a small change in global temperature can greatly affect the amount of sea ice and due to the shrinking reflective surface that keeps the ocean cool, this sparks a cycle of ice shrinking and temperatures warming. As a result, the polar regions are the most susceptible places to climate change on the planet. Furthermore, sea ice affects
4510-595: The annual cycle of solar insolation and of ocean and atmospheric temperature and of variability in this annual cycle. In the Arctic, the area of ocean covered by sea ice increases over winter from a minimum in September to a maximum in March or sometimes February, before melting over the summer. In the Antarctic, where the seasons are reversed, the annual minimum is typically in February and the annual maximum in September or October and
4592-415: The bottom of the ocean. This cold water moves along the ocean floor towards the equator, while warmer water on the ocean surface moves in the direction of the poles. This is referred to as " conveyor belt motion" and is a regularly occurring process. In order to gain a better understanding about the variability, numerical sea ice models are used to perform sensitivity studies . The two main ingredients are
4674-499: The coastline. Only the top layer of water needs to cool to the freezing point. Convection of the surface layer involves the top 100–150 m (330–490 ft), down to the pycnocline of increased density. In calm water, the first sea ice to form on the surface is a skim of separate crystals which initially are in the form of tiny discs, floating flat on the surface and of diameter less than 0.3 cm (0.12 in). Each disc has its c-axis vertical and grows outwards laterally. At
4756-499: The coldest recorded temperature is approximately −68 °C (−90 °F). Coastal Arctic climates are moderated by oceanic influences, having generally warmer temperatures and heavier snowfalls than the colder and drier interior areas. The Arctic is affected by current global warming , leading to climate change in the Arctic , including Arctic sea ice decline , diminished ice in the Greenland ice sheet , and Arctic methane emissions as
4838-399: The concentrations exceed the levels of densely populated urban areas. An example of this is the phenomenon of Arctic haze , which is commonly blamed on long-range pollutants. Another example is with the bioaccumulation of PCB's ( polychlorinated biphenyls ) in Arctic wildlife and people. There have been many proposals to preserve the Arctic over the years. Most recently a group of stars at
4920-413: The convention in 1996), Russia (ratified in 1997), Canada (ratified in 2003) and the Kingdom of Denmark (ratified in 2004) launched projects to establish claims that certain sectors of the Arctic seabed should belong to their territories. On 2 August 2007, two Russian bathyscaphes , MIR-1 and MIR-2 , for the first time in history descended to the Arctic seabed beneath the North Pole and placed there
5002-403: The first "ice free" Arctic summer might occur vary. Antarctic sea ice extent gradually increased in the period of satellite observations, which began in 1979, until a rapid decline in southern hemisphere spring of 2016. Sea ice provides an ecosystem for various polar species, particularly the polar bear , whose environment is being threatened as global warming causes the ice to melt more as
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#17328697717865084-712: The grey ice stage) or ridge (at the grey-white ice stage). First-year sea ice is ice that is thicker than young ice but has no more than one year growth. In other words, it is ice that grows in the fall and winter (after it has gone through the new ice – nilas – young ice stages and grows further) but does not survive the spring and summer months (it melts away). The thickness of this ice typically ranges from 0.3 m (0.98 ft) to 2 m (6.6 ft). First-year ice may be further divided into thin (30 cm (0.98 ft) to 70 cm (2.3 ft)), medium (70 cm (2.3 ft) to 120 cm (3.9 ft)) and thick (>120 cm (3.9 ft)). Old sea ice
5166-429: The ground, forming tundra . An example of a dwarf shrub is the bearberry . As one moves northward, the amount of warmth available for plant growth decreases considerably. In the northernmost areas, plants are at their metabolic limits, and small differences in the total amount of summer warmth make large differences in the amount of energy available for maintenance, growth and reproduction. Colder summer temperatures cause
5248-403: The ice also serves a role in maintaining cooler polar temperatures by reflecting much of the sunlight that hits it back into space. As the sea ice melts, its surface area shrinks, diminishing the size of the reflective surface and therefore causing the earth to absorb more of the sun's heat. As the ice melts it lowers the albedo thus causing more heat to be absorbed by the Earth and further increase
5330-422: The ice growth period, its bulk brine volume is typically below 5%. Air volume fraction during ice growth period is typically around 1–2 %, but may substantially increase upon ice warming. Air volume of sea ice in can be as high as 15 % in summer and 4 % in autumn. Both brine and air volumes influence sea-ice density values, which are typically around 840–910 kg/m for first-year ice. Sea-ice density
5412-571: The ice is riddled with brine-filled channels which sustain sympagic organisms such as bacteria, algae, copepods and annelids, which in turn provide food for animals such as krill and specialised fish like the bald notothen , fed upon in turn by larger animals such as emperor penguins and minke whales . A decline of seasonal sea ice puts the survival of Arctic species such as ringed seals and polar bears at risk. Other element and compounds have been speculated to exist as oceans and seas on extraterrestrial planets. Scientists notably suspect
5494-426: The ice surface during the melt season lower the albedo such that more solar radiation is absorbed, leading to a feedback where melt is accelerated. The presence of melt ponds is affected by the permeability of the sea ice (i.e. whether meltwater can drain) and the topography of the sea ice surface (i.e. the presence of natural basins for the melt ponds to form in). First year ice is flatter than multiyear ice due to
5576-424: The increase. The Arctic contains some of the last and most extensive continuous wilderness areas in the world, and its significance in preserving biodiversity and genotypes is considerable. The increasing presence of humans fragments vital habitats. The Arctic is particularly susceptible to the abrasion of groundcover and to the disturbance of the rare breeding grounds of the animals that are characteristic to
5658-484: The interaction between fast ice and the drifting pack ice. Level ice is sea ice that has not been affected by deformation and is therefore relatively flat. Leads and polynyas are areas of open water that occur within sea ice expanses even though air temperatures are below freezing and provide a direct interaction between the ocean and the atmosphere, which is important for the wildlife. Leads are narrow and linear – they vary in width from meter to km scale. During
5740-650: The lack of dynamic ridging, so ponds tend to have greater area. They also have lower albedo since they are on thinner ice, which blocks less of the solar radiation from reaching the dark ocean below. Sea ice is a composite material made up of pure ice, liquid brine, air, and salt. The volumetric fractions of these components—ice, brine, and air—determine the key physical properties of sea ice, including thermal conductivity, heat capacity, latent heat, density, elastic modulus, and mechanical strength. Brine volume fraction depends on sea-ice salinity and temperature, while sea-ice salinity mainly depends on ice age and thickness. During
5822-406: The major impacts to the region from climate change the near climate future of the region will be extremely different under all scenarios of warming. The effects of climate change in the Arctic include rising temperatures, loss of sea ice , and melting of the Greenland ice sheet . Potential methane release from the region, especially through the thawing of permafrost and methane clathrates ,
5904-407: The movement of ocean waters. In the freezing process, much of the salt in ocean water is squeezed out of the frozen crystal formations, though some remains frozen in the ice. This salt becomes trapped beneath the sea ice, creating a higher concentration of salt in the water beneath ice floes. This concentration of salt contributes to the salinated water's density and this cold, denser water sinks to
5986-464: The northernmost tree line roughly follows the isotherm at the boundary of this region. The climate of the Arctic region is characterized by cold winters and cool summers. Its precipitation mostly comes in the form of snow and is low, with most of the area receiving less than 50 cm (20 in). High winds often stir up snow, creating the illusion of continuous snowfall. Average winter temperatures can go as low as −40 °C (−40 °F), and
6068-489: The ocean. Depending on location, sea ice expanses may also incorporate icebergs. Sea ice does not simply grow and melt. During its lifespan, it is very dynamic. Due to the combined action of winds, currents, water temperature and air temperature fluctuations, sea ice expanses typically undergo a significant amount of deformation. Sea ice is classified according to whether or not it is able to drift and according to its age. Sea ice can be classified according to whether or not it
6150-595: The possibility that the Arctic region will become a prime trade route . One harbinger of the opening navigability of the Arctic took place in the summer of 2016 when the Crystal Serenity successfully navigated the Northwest Passage, a first for a large cruise ship. In addition, it is believed that the Arctic seabed may contain substantial oil fields which may become accessible if the ice covering them melts. These factors have led to recent international debates as to which nations can claim sovereignty or ownership over
6232-510: The predecessor culture. The evidence suggested that Inuit descend from the Birnirk of Siberia, who through the Thule culture expanded into northern Canada and Greenland, where they genetically and culturally completely replaced the Indigenous Dorset people some time after 1300 CE. The question of why the Dorset disappeared so completely has led some to suggest that Thule invaders wiped out
6314-566: The presence of sea ice abutting the calving fronts of ice shelves has been shown to influence glacier flow and potentially the stability of the Antarctic ice sheet . The growth and melt rate are also affected by the state of the ice itself. During growth, the ice thickening due to freezing (as opposed to dynamics) is itself dependent on the thickness, so that the ice growth slows as the ice thickens. Likewise, during melt, thinner sea ice melts faster. This leads to different behaviour between multiyear and first year ice. In addition, melt ponds on
6396-657: The region. The Arctic also holds 1/5 of the Earth's water supply. During the Cretaceous time period , the Arctic still had seasonal snows, though only a light dusting and not enough to permanently hinder plant growth. Animals such as the Chasmosaurus , Hypacrosaurus , Troodon , and Edmontosaurus may have all migrated north to take advantage of the summer growing season, and migrated south to warmer climes when winter came. A similar situation may also have been found amongst dinosaurs that lived in Antarctic regions, such as
6478-432: The size, abundance, productivity and variety of plants to decrease. Trees cannot grow in the Arctic, but in its warmest parts, shrubs are common and can reach 2 m (6 ft 7 in) in height; sedges , mosses and lichens can form thick layers. In the coldest parts of the Arctic, much of the ground is bare; non-vascular plants such as lichens and mosses predominate, along with a few scattered grasses and forbs (like
6560-548: The water dammed and diverted to a nearby lake. Three smaller lakes at High Lake would also be drained. Grays Bay would be substantially filled in." In their August 2012 proposal which has since been revised, MMG Minerals described the planned facilities at the Grays Bay Port that would "include a dock, concentration storage shed, fuel storage facilities and a camp. These facilities will support storage of concentrate, loading of bulk-carrier ships, and re-supply of fuel and goods for
6642-403: The waters of the Arctic. Sea ice Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world's sea ice is enclosed within the polar ice packs in the Earth's polar regions : the Arctic ice pack of
6724-464: The winter, the water in leads quickly freezes up. They are also used for navigation purposes – even when refrozen, the ice in leads is thinner, allowing icebreakers access to an easier sail path and submarines to surface more easily. Polynyas are more uniform in size than leads and are also larger – two types are recognized: 1) Sensible-heat polynyas , caused by the upwelling of warmer water and 2) Latent-heat polynyas , resulting from persistent winds from
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