The Arctic is the northern circumpolar Earth region, and covers the northern parts of three continents, North America, Asia and Europe, and also the large extent of ice -covered Arctic Ocean; it is one of two earthly so-called polar caps.
The name Arctic comes from the Greek word Arktos ἄρκτος, Bear ' from. The adjective Arktikos, arctic ' north ' designated the country under the constellation of the Great Bear. The North Star is located at just under 44 minutes of arc deviation almost vertically over the North Pole and is now part of the constellation Ursa Minor.
- 2.1 Population
- 2.2 Flora
- 2.3 Fauna
The Arctic region
The area of the Arctic is defined by climatic and vegetationsgeografische criteria: for example, the tree line or the July isotherm of 10 ° C are decisive for the distinction from the more southern regions of the world. In earlier times it was simply defined as " region north of the Arctic Circle" (66 ° 33 ' north latitude ). The latter was for many natural sciences dealing with the Arctic, unsuitable, since the climatic zone of the Arctic is not limited by the Arctic Circle.
During the ice-covered continent of Antarctica one, Antarctica surrounds, is the northern polar region of a large sea that is bounded to the south by the northern borders of the three continents North America, Asia and Europe. The geographic North Pole is in the middle of at this point 4,261 meters deep, year round frozen Arctic Ocean.
Especially in the high Arctic snow and ice cover throughout the year a great part of the land and ocean, while in the southern Arctic regions larger surface areas defrost in the summer and are therefore more livable. These regions are Pingos - ice lenses formed by rounded hills - a typical landscape phenomenon. Overall prevail in the Arctic despite increasing climate change extreme environmental conditions.
From the fossil record, as those of the Margaret Formation of Ellesmere Island or a mummified forest on Axel Heiberg Island, stating that in the Arctic in the lower to middle Eocene, 40-50 million years reigned warm temperate temperatures and here up to 50 -meter-high redwood trees grew. The Arctic Ocean had at that time locally and seasonally limited to even sub-tropical water temperatures. In drill core remains were discovered by freshwater plants that occur today among other things in rice crops. Therefore, it is assumed that the Arctic Ocean could have been an almost closed off from the ocean inland sea more than 40 million years ago, the upper water layer was comparatively low in salt by precipitation -induced freshwater entries. Other finds evidence of biological violent upheavals and the sudden extinction of many organisms in the subsequent period.
At the beginning of the Oligocene, about 33 million years ago the earth cooled down, producing ice caps at the poles. The icing reached the Antarctic and Greenland 25 6 million years ago. 6000-7000 years ago, the Arctic was probably ice free for a long time periodically.
Anthropogenic climate change
For over half a century a decrease in sea ice area is observed. She has gained considerably in the recent past at speed, so natural variations appear as basic increasingly unlikely and the global warming is now regarded as the main cause.
Measurements from 2007 show a decline in the ice compared to the average for the years 1978 to 2000 by 40-45 % over 3 million square kilometers. In 2007 alone, are melted over a million square kilometers of ice. Should this trend continue, the Arctic could be ice-free in summer by 2030. Northeast Passage and the Northwest Passage could be temporarily commercial waterway suitable from about 2019.
In autumn 2008 the temperatures have reached 5 degrees above normal a new heat record for this time of year, according to a report of the American weather and NOAA. One reason for this is the steady retreat of sea ice, which means less sunlight is reflected into space. This in turn leads to further increase in the air temperature. This feedback mechanism is called ice albedo feedback.
Also, the thickness of Arctic sea ice decreases. Together with the area reduction results in a drastic volume shrinkage, which indicates a complete loss of sea ice during the summer prior to 2020, while the IPCC nor for the period to 2090 foresaw no complete disappearance of ice in his report of 2007.
Also on Greenland ice sheet takes off: In 2007, the island lost a volume of 101 cubic kilometers. This contributed to the fact that sea levels are rising by 0.25 inches per year in the Arctic. Consequences are already detectable in the ecosystem: This increases the population of geese, while reindeer herds are smaller.
In June 2011, the ESA published a new map of the Arctic ice sheet that was created with the help of CryoSat -2. For the first time in the history of Arctic Eisbeobachtung can now also the thickness of the ice to be measured precisely. Therefore, the operator of the satellite are talking about the beginning of a new series of measurements.
Parts of the territories of Russia, the United States ( Alaska) and in Canada, the dependent territories, Greenland ( administered by Denmark) and Svalbard ( to Norway) and the Lapland region ( on the territory of Norway, Sweden and Finland) extend across the Arctic region.
Politically, the littoral states have agreed on a sector principle that each country assigns the territory lying within the sectors that arise from a straight connection to their borders with the North Pole. This is currently compounded by the onset of oil and gas development in these areas. Because of the raw materials and the associated race it already emerging differences between the riparian countries; Caused a stir in this context Russia, which by means of a U- boat 's disputed territorial claims gave emphasis in mid-2007 and its flag placed exactly at the geographic North Pole.
To edit policy issues around the Arctic, the Arctic Council was established in 1996.
Life in the Arctic
In the Arctic, currently live a total of about one million people. Among the Polar Eskimo peoples include the population ( about 150,000 ), Nenets ( Samoyed called earlier, about 40,000 ), Yakuts (about 330,000 ), seeds (about 70,000 ) and Evenki (approx. 35,000 ). Also, living in the Arctic many Scandinavians, Russians and North Americans, including members of the First Nations and Alaska Natives, so the indigenous peoples of northern Canada and Alaska. To protect the environment and the indigenous people in the Arctic, the Arctic Council was established in 1996.
The northernmost cultural area of North America ( breakdown of ethnic groups according to similar characteristics) is also called an " Arctic ".
In the Arctic regions of growing plants are mainly related to widespread alpine regions species, but is influenced her life cycle by the severe extreme environmental conditions of tundra and ice fields. Arctic environmental factors are strong differences in temperature, permafrost, extremely changing sunlight and heavy snow storms that affect the vegetation by abrasion.
In the Arctic regions, only a limited number of mammalian species is native and also of fish species, the Arctic is poor. The birds, however, the arctic on a great wealth, which is not least that many migratory birds come here to breed.
Estimated to occur in the arctic regions affected in front of around 1,000 species of insects. A special importance is attached to bloodsucking piercing and black flies, and also bumblebees and butterflies. In addition, in the tundra occurs on a larger number of spider species.
- Polar Bears
- Arctic fox
- Arctic Hare
- Arctic Wolf
- Seals, especially ringed and bearded seals, seals, walruses
- Whales, especially Greenland whales, belugas and narwhals
- Ground squirrels ( gophers )
- Arctic grayling
- Greenland shark
- Nine-spined stickleback
- Arctic cod
- Lake trout
- Lump fish ( Cyclopterus lumpus )
- Arctic char
- White salmon
- Thick-billed murre
- Ducks, including eider, long-tailed duck, king eider
- Falcon ( falcon, peregrine falcon )
- Goose, including Canada Goose, Brent Goose, Snow Goose
- Plover, including golden plover, gray plover
- Great Skua ( Skua )
- Black Guillemot ( Schwarzlumme )
- Canada Crane
- Little auk
- Arctic Tern
- Gulls, including Bonapartemöwe, Kittiwake, Glaucous Gull, Ivory Gull, Rosenmöwe, Sabine's Gull, Herring Gull, Thayermöwe
- Skuas ( Skua, Arctic Skua )
- Rough-legged buzzard
- Snow Bunting
- Snowy Owl
- Ptarmigan ( alpine and willow ptarmigan )
- Lapland Bunting
- Golden eagle
- Ruddy Turnstone
- Beach skiers
- Loons, including common loon, Yellow -billed Diver, Black-throated Diver, Red-throated Diver
- Tundra swan