Arctic Ocean
Up to 5669 m deep Arctic Ocean , and the Arctic Ocean , Arctic Ocean , Arctic Ocean or short Arctic called, with 14.09 million square kilometers , the smallest ocean of the earth . With an average water depth of only 987 m, it is one of the shallower waters. It is sometimes seen as a tributary to the Atlantic Ocean ; it is in the Arctic .
geography
location
The Arctic Ocean , located in the far north of the northern hemisphere of the earth is, is located between each adjacent in southern compass continents Asia , Europe and North America . Because it lies between several continents and although scientifically one of the five oceans on earth, it is also considered the intercontinental Mediterranean .
The Arctic Ocean is connected to the Atlantic by the approximately 1500 km wide European Arctic Ocean between Greenland and Northern Europe or Scandinavia , as well as by some winding roads that lead through the heavily fragmented north Canadian island world to the broad Davis Strait west of Greenland. It is only connected to the Pacific by the approximately 85 km wide Bering Strait .
The Arctic Ocean has an extension of around 14.09 million km² and is largely covered by ice . The ice cover increases and decreases with the seasons. Overall, the ice surface has decreased significantly since the 1970s.
In Molloytief , which is 165 km west of Spitsbergen , it is up to 5669 m deep.
Tributaries
Between Greenland and Scandinavia , the Arctic Ocean borders the European Arctic Ocean (the northernmost marginal sea of the Atlantic ) and between Alaska and Eastern Siberia it borders the Bering Strait , which connects to the Bering Sea (the northernmost marginal sea of the Pacific ). The Greenland Sea and the European Arctic Ocean are also marginal seas of the Atlantic because they lead to this ocean . Other secondary seas of the Arctic Ocean are:
| designation | Art | Area (km²) | Average depth (m) |
|---|---|---|---|
| Beaufortsee | Randmeer | 476,000 | 1.004 |
| Lincoln lake | Randmeer | 64,000 | |
| Wandelsee | Randmeer | ||
| Greenland Sea | Randmeer | 1,205,000 | 1,440 |
| European Arctic Ocean | Randmeer | 1,100,000 | < 2,000 |
| White sea | Randmeer | 90,000 | 60 |
| Barents Sea | Randmeer | 1,405,000 | 230 |
| Kara Sea | Randmeer | 880,000 | 118 |
| Laptev Lake | Randmeer | 660,000 | 578 |
| East Siberian Sea | Randmeer | 936,000 | 45 |
| Hudson Bay | Inland sea | 1,230,000 | 200 |
| Chukchi Sea | Randmeer | 582,000 | 77 |
Tributaries
The most important tributaries are the Ob , Yenisei , Lena and Kolyma , the tributaries of the Barents Sea and, from North America, the Yukon River in Alaska and the Mackenzie River with Hudson Bay . The researchers working with Bruce Peterson claim that the amount of freshwater that entered the Arctic Ocean increased by around 128 km³ or around seven percent between 1936 and 1999.
Neighbor states
The Arctic Ocean borders the northern areas of these countries and parts of the country: Alaska ( USA ), Canada and Greenland ( Denmark ), Iceland , Norway and Russia . The political affiliation of different parts of the Arctic Ocean to the neighboring states is, however, controversial .
Landmarks
Seabed
Within the Arctic Ocean or on its sea floor there are thresholds , deep-sea basins and a sea depression .
The thresholds include the Fletcher back , the Gakkel back , the Lomonossow back ( Harris's threshold ), the East Siberian threshold and the Chukchi threshold . The three large deep-sea basins, which are all located in the center of the ocean, are the Eurasian Basin up to 5449 m deep in Litketief , the Canadian Basin up to 4994 m deep and the Central Arctic Basin up to 3290 m deep .
Island world
It also borders on these islands and archipelagos to the north : Banks Island , Franz Joseph Land , Queen Elisabeth Islands with Ellesmere Island , Greenland , Iceland , Kolgujew , New Siberian Islands , Novaya Zemlya , Severnaya Zemlya , Svalbard and Wrangel Island .
shipping
The Arctic Ocean is used approximately three to five months a year for shipping operated by Russia in the Northeast Passage and the United States and Canada in the Northwest Passage . The Russian state maintains a nuclear icebreaker fleet for this purpose . There are also a small number of expedition cruises. Furthermore, submarines from several nations are active in the Arctic Ocean . The main ports are Churchill , Arkhangelsk , Severomorsk , Dikson , Murmansk , Pewek and Tiksi .
On August 27, 2014, the expedition cruise ship Hanseatic under captain Thilo Natke advanced to a distance of around 480 kilometers to the North Pole; it came to a north position which until then could only be reached by icebreakers and thus set a world record.
polar ice
border (record position 85 ° 40.7818 'N, 135 ° 38.8735' E)
North Pole
The four poles of the northern hemisphere lie within the Arctic Ocean or on its islands .
Wildlife
Due to the pronounced seasonality of 2 to 6 months of midnight sun and polar night in the Arctic Ocean, the primary production of photosynthetic organisms such as ice algae and phytoplankton is limited to the spring and summer months (March / April to September). Important consumers of primary producers in the central Arctic Ocean and the adjacent shelf seas are zooplankton, especially copepods ( Calanus finmarchicus , Calanus glacialis and Calanus hyperboreus ) and krill , as well as ice-associated fauna (e.g. amphipods ). These primary consumers form an important link between the primary producers and higher trophic levels . The composition of the higher trophic levels in the Arctic Ocean varies with the region (Atlantic side vs. Pacific side) and with the sea ice cover. Secondary consumers in the Barents Sea , an Arctic shelf sea influenced by the Atlantic, are mainly subarctic species, including herring , young cod and capelin . In the ice-covered regions of the central Arctic Ocean, the polar cod is a key predator for primary consumers. The top predators in the Arctic Ocean - marine mammals such as seals , whales and polar bears , hunt fish.
Endangered marine life in the Arctic Ocean includes walruses and whales. The area has a fragile ecosystem and is particularly exposed to climate change as it is warming faster than the rest of the world. Yellow hairy jellyfish are abundant in Arctic waters. The banded butterfish is the only species of butterfish that lives in the Arctic Ocean.
About 50 species of seabirds, including auks , petrels , cormorants , gulls , terns and birds of prey , crowd the nesting rocks and beaches in June and July. They all get their food from the sea. Eight species of seals breed in the Arctic, six of them between the ice . The largest are the walruses , whose bulls are over four meters long and weigh more than a ton. They live mainly along the coasts of Eastern Siberia, Alaska, Canada, Greenland and Northern Scandinavia, and dive in shallow water for mussels and other bottom invertebrates. The young are born on the drift ice in May . Arctic fur seals only breed on the islands of the Bering Strait .
Danger
There are fears that the groundwater streams of the Tetscha and Ob rivers could lead to heavily contaminated water from Lake Karachay entering the Arctic Ocean. This would contaminate one of the last great wilderness areas. Possible consequences for the flora and fauna cannot be precisely estimated.
See also
Web links
- CIA World Factbook: Arctic Ocean (English)
- Cryosphere today - graphics on the current ice cover of the polar regions of the earth with archive
- Map of the seabed (Engl.)
- R-ArcticNet - A Database of Pan-Arctic River Discharge
- Marine Ecoregions (map)
- How the Arctic Ocean got salty. Alfred Wegener Institute , June 6, 2017(original article in doi : 10.1038 / NCOMMS15681 ).
swell
- ↑ International Bathymetric Chart of the Arctic Ocean (IBCAO). June 8, 2012, accessed April 13, 2020 .
- ↑ a b Martin Klenke, Hans Werner Schenke: A new bathymetric model for the central Fram Strait. In: Marine geophysical researches. 23, 2002, pp. 367-378 (English) doi: 10.1023 / A: 1025764206736
- ^ Dieter Kasang: Sea ice in climate change. On: Hamburger Bildungsserver, accessed on August 10, 2020.
- ↑ Science, Vol. 298, p. 2171
- ↑ Fresh water in the Arctic Ocean cools Europe. (No longer available online.) In: 3sat . Formerly in the original ; Retrieved on April 23, 2007 ( archive links only lead to the indication that the content may no longer be displayed. ). ( Page no longer available , search in web archives )
- ^ E. Leu, JE Søreide, et al .: Consequences of changing sea-ice cover for primary and secondary producers in the European Arctic shelf seas: Timing, quantity, and quality . In: Progress of Oceanography . tape 90 , no. 1-4 , 2011, pp. 18-32 (English).
- ↑ KN Kosobokova, RR Hopcroft: Patterns of zooplankton diversity through the depths of the Arctic's central basins . In: Marine Biodiversity . tape 41 , 2011, p. 29-50 (English).
- ↑ Ask1.org: Mayak - Beacon of Nuclear Madness. ( Memento of the original from December 23, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ ( Page no longer available , search in web archives: Sandia National Lab - Advanced Simulation and Computing Contamination Sites )
