Arctic - Animals At The North Pole

The Arctic (/Ëˆitle="/É'Ër/ 'ar' in 'far'">É'ËrktÉªk/ or /ËˆÉ'ËrtÉªk/) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Alaska (United States), Canada, Finland, Greenland (Denmark), Iceland, Norway, Russia, and Sweden. Land within the Arctic region has seasonally varying snow and ice cover, with predominantly treeless permafrost-containing tundra. Arctic seas contain seasonal sea ice in many places.

The Arctic region is a unique area among Earth's ecosystems. For example, the cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions. In recent years, Arctic sea ice decline has been caused by global warming. Life in the Arctic includes organisms living in the ice, zooplankton and phytoplankton, fish and marine mammals, birds, land animals, plants and human societies. Arctic land is bordered by the subarctic.

Definition and etymology

The word Arctic comes from the Greek word á¼€ÏÎºÏ„Î¹ÎºÏŒÏ‚ (arktikos), "near the Bear, northern" and that from the word á¼„ÏÎºÏ„Î¿Ï‚ (arktos), meaning bear. The name refers either to the constellation 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 Polaris, the Pole star, also known as the North Star.

There are a number of definitions of what area is contained within the Arctic. The area can be defined as north of the Arctic Circle (66Â° 33'N), the approximate southern limit of the midnight sun and the polar night. Another definition of the Arctic is the region where the average temperature for the warmest month (July) is below 10Â Â°C (50Â Â°F); the northernmost tree line roughly follows the isotherm at the boundary of this region.

Climate

The Arctic's climate 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 50Â cm (20Â in). High winds often stir up snow, creating the illusion of continuous snowfall. Average winter temperatures can be as low as âˆ'40Â Â°C (âˆ'40Â Â°F), and the coldest recorded temperature is approximately âˆ'68Â Â°C (âˆ'90Â Â°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 Arctic sea ice shrinkage, diminished ice in the Greenland ice sheet, and Arctic methane release as the permafrost thaws.

Due to the poleward migration of the planet's isotherms (about 35Â mi (56Â km) 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 spectacular result of Arctic shrinkage is sea ice loss. There is a large variance in predictions of Arctic sea ice loss, with models showing near-complete to complete loss in September from 2040 to some time well beyond 2100. About half of the analyzed models show near-complete to complete sea ice loss in September by the year 2100.

Flora and fauna

Arctic life is characterized by adaptation to short growing seasons with long periods of sunlight, and to cold, dark, snow-covered winter conditions.

Plants

Arctic vegetation is composed of plants such as dwarf shrubs, graminoids, herbs, lichens and mosses, which all grow relatively close to the ground, forming tundra. 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 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 2Â m (6Â ft 7Â 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 the Arctic poppy).

Animals

Herbivores on the tundra include the Arctic hare, lemming, muskox, and caribou. They are preyed on by the snowy owl, Arctic fox, Grizzly bear, and 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 land animals include wolverines, ermines, and Arctic ground squirrels. Marine mammals include seals, walrus, and several species of cetaceanâ€"baleen whales and also narwhals, killer whales and belugas. An excellent and famous example of a ring species exists and has been described around the arctic circle in the form of the Larus gulls.

Natural resources

The Arctic includes sizable natural resources (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 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 the region. The Arctic also holds 1/5 of the Earth's water supply.

Palaeontology

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 the winter came. A similar situation may also have been found amongst dinosaurs that lived in Antarctic regions, such as 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 70Â°Â N but at the time (70 million years ago) was 10Â° further north.

Indigenous population

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 BC. AST consisted of several Paleo-Eskimo cultures, including 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 1050â€"550 BC. With the exception of the Quebec/Labrador peninsula, the Dorset culture vanished around 1500 AD. Supported by genetic testing, evidence shows that descendants of 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 9thâ€"10th centuries. 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 the predecessor culture. Others believe the Thule displaced the Dorset. By 1300, 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. Over time, the Inuit have migrated throughout the Arctic regions of Canada, Greenland, Russia and the United States.

Other Circumpolar North indigenous peoples include the Buryat, Chukchi, Evenks, Inupiat, Khanty, Koryaks, Nenets, Sami, Yukaghir, Gwich'in, and Yupik. The Yupik still refer to themselves as Eskimo, which means "snowshoe netters", not "raw meat eaters" as it is sometimes mistakenly translated.

International cooperation and politics

The eight Arctic nations (Canada, Denmark (Greenland & The Faroe Islands), Finland, Iceland, Norway, Sweden, Russia, and USA) are all members of the Arctic Council, as are organizations representing six indigenous populations. 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.

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 the Arctic Council, and the Barents Euro-Arctic Council are more examples of collaborative international Arctic research.

Territorial claims

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 Oceanâ€"Canada, Denmark (via Greenland), Iceland, Norway, Russia, and the United Statesâ€"are limited to a 200 nautical miles (370Â km; 230Â 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 the convention in 1996), Russia (ratified in 1997), Canada (ratified in 2003) and 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 a Russian flag made of rust-proof titanium alloy. The mission was a scientific expedition, but 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, Denmark, Norway, Russia, and the United States met in Ilulissat, Greenland on 28 May 2008 at the Arctic Ocean Conference and announced 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, Denmark is claiming the continental shelf between Greenland and the North Pole. The Russian Federation is claiming a large swath of seabed along the Lomonosov Ridge but confined to its sector of the Arctic.

Exploration

Since 1937, the larger portion of the Asian-side Arctic region has been extensively explored by Soviet and Russian manned drifting ice stations. Between 1937 and 1991, 88 international polar crews established and occupied scientific settlements on the drift ice and were carried thousands of kilometers by the ice flow.

Pollution

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 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.

Preservation

There have been many proposals to preserve the Arctic over the years. Most recently a group of stars at the Rio Earth Summit, on 21 June 2012, proposed protecting the Arctic, similar to the Antarctic protection. 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.

Climate change

According to research in 2016 with the current emission cuts, the Arctic will lose all its ice in summer within ca 20 years since the average westernerâ€™s carbon emissions destroy 30 square metres of Arctic sea ice every year.

The Arctic 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 warming in 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 climate models on which the IPCC report Number 4 is based give a range of predictions of Arctic sea ice loss, showing near-complete to complete loss in September anywhere from 2040 to some time well beyond 2100. About half of the analyzed models show near-complete to complete sea ice loss in September by the year 2100. More recently, the Catlin Arctic Survey concluded that summer ice loss would occur around 2029. It has been apparent though since 2007, that those models grossly underestimate sea ice loss.

As can be seen in the two plot at the right, since about 1995 to 2000, all three size numbers of the Arctic sea ice shield (extent, area and volume) are decreasing in an accelerated way. This downward movement is modulated by statistical variations, which lead to considerable media attention, when a new record has been reached.

Concerning melting records, 2012 was a productive year, thus corroborating the tendency of the past decade. This may have been furthered by a strong summer storm cyclone, a rare event in the Arctic, which spread the already very thin ice and caused mixing of the cold surface waters with deeper warmer water layers. According to the University of Bremen, in September 2011 the Arctic ice cap was smaller than ever recorded (the satellite measurements started in the 1970s). Arctic ice is declining in area and thinning. Arctic temperatures have risen more than twice as fast as the global average over the past half century. The speed of change has shocked scientists. If current trends continue, a largely ice-free Arctic in the summer is likely within 30 years â€" up to 40 years earlier than was anticipated by the IPCC Fourth Assessment Report.

As the volume of sea ice until recently could not be measured by remote sensing as easy as its extent, numerical models have been made to estimate the ice thickness field between known points, which then is summed up to yield ice volume. The resulting volume over time reveals a much stronger loss of ice than ice extent studies suggest.

The current Arctic warming is leading to fears of 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. On millennial time-scales, decomposition of methane hydrates in the Arctic seabed might also amplify global warming. Previous methane release events have been linked to the great dying, a mass extinction event at the boundary of the Permian and Triassic, and the Paleoceneâ€"Eocene Thermal Maximum, in which temperatures abruptly increased.

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, the shipping routes through the northernmost latitudes, more navigable, raising 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 the waters of the Arctic.

The National Oceanic and Atmospheric Administration's Arctic Report Card presents annually updated, peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records.

"Participation in international cooperation on climate change can be enhanced by monetary transfers, market-based mechanisms, technology transfer, and trade-related measures."

Arctic waters

Arctic lands

Notes

References

Bibliography

Gibbon, Guy E.; Kenneth M. Ames (1998). Archaeology of prehistoric native America: an encyclopedia. Volume 1537 of Garland reference library of the humanities. Taylor & Francis. ISBNÂ 0-8153-0725-X.Â

External links

Arctic Report Card
International Arctic Research Center
Arctic Theme Page Comprehensive Arctic Resource from NOAA.
WWF International Arctic Programme Arctic environment and conservation information
Bering Sea Climate and Ecosystem Current state of the Bering Sea Climate and Ecosystem. Comprehensive resource on the Bering Sea with viewable oceanographic, atmospheric, climatic, biological and fisheries data with ecosystem relevance, recent trends, essays on key Bering Sea issues, maps, photos, animals and more. From NOAA.
Toxoplasma gondii in the Subarctic and Arctic
Protecting U.S. Sovereignty: Coast Guard Operations in the Arctic: Hearing before the Subcommittee on Coast Guard and Maritime Transportation of the Committee on Transportation and Infrastructure, House of Representatives, One Hundred Twelfth Congress, First Session, 1 December 2011

Maps

Arctic Environmental Atlas Circum-Arctic interactive map, with multiple layers of information
Interactive Satellite Map with daily update (true color/infrared)

Media

The Emerging Arctic An Infoguide from the Council on Foreign Relations
"Global Security, Climate Change, and the Arctic" â€" streaming video of November 2009 symposium at the University of Illinois
Implications of an Ice-Free Arctic for Global Security â€" November 2009 radio interview with Professor Klaus Dodds (Royal Holloway, University of London)
The Canadian Museum of Civilization â€" The Story of the Canadian Arctic Expedition of 1913â€"1918
UNEP/GRID-Arendal Maps and Graphics library Information resources from the UN Environment programme
Arctic Institute of North America Digital Library Over 8000 photographs dating from the late 19th century through the 20th century.
euroarctic.com News service from the Barents region provided by Norwegian Broadcasting Corp (NRK), Swedish Radio (SR) and STBC Murman.
arcticfocus.com Independent News service covering Arctic region with daily updates on environment, Arctic disputes and business
Vital Arctic Graphics Overview and case studies of the Arctic environment and the Arctic Indigenous Peoples.
Arctic and Taiga Canadian Atlas
Scientific Facts on Arctic Climate Change
PolarTREC PolarTREC-Teachers and Researchers Exploring and Collaborating
Arctic Change: Information on the present state of Arctic ecosystems and climate, presented in historical context (from NOAA, updated regularly)
Monthly Sea Ice Outlook
UN Environment Programme Key Polar Centre at UNEP/GRID-Arendal
Arctic Geobotanical Atlas, University of Alaska Fairbanks
Polar Discovery
Arctic Transform Transatlantic Policy Options for Supporting Adaptation in the Marine Arctic
ArcticStat Circumpolar Database

Arctic - Animals At The North Pole

Jumat, 24 Februari 2017