Antarctic

Coordinates: 90°00′S 00°00′W / 90.000°S -0.000°E / -90.000; -0.000
Source: Wikipedia, the free encyclopedia.
This article is about the region. For the continent, see Antarctica. For other uses, see Antarctic (disambiguation).

A map of the Antarctic region, including the Antarctic Convergence and the 60th parallel south
The Antarctic Plate

The Antarctic (/ænˈtɑːrtɪk/ or /ænˈtɑːrktɪk/, American English also /æntˈɑːrtɪk/ or /æntˈɑːrktɪk/; commonly /æˈnɑːrtɪk/)[Note 1] is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole.

The Antarctic comprises the continent of

island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately 32 to 48 km (20 to 30 mi) wide and varying in latitude seasonally.[4] The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent (14 million km2) is the surface area of the Antarctica continent itself. All of the land and ice shelves south of 60°S latitude are administered under the Antarctic Treaty System
.

Biogeographically, the Antarctic realm is one of eight biogeographic realms on Earth's land surface. Climate change in Antarctica is particularly important because the melting of the Antarctic ice sheet has a high potential to add to the global sea level rise. Further, this melting also disrupts the flow of Southern Ocean overturning circulation, which would have significant effects on the local climate and marine ecosystem functioning.

Geography

An October 2006 NASA satellite image of the Antarctic without its periphery of unattached sea ice
Location of the Antarctic on a map of the Earth

As defined by the Antarctic Treaty System, the Antarctic region is everything south of the 60°S latitude. The Treaty area covers Antarctica and the archipelagos of the Balleny Islands, Peter I Island, Scott Island, the South Orkney Islands, and the South Shetland Islands.[5] However, this area does not include the Antarctic Convergence, a transition zone where the cold waters of the Southern Ocean collide with the warmer waters of the north, forming a natural border to the region.[6] Because the Convergence changes seasonally, the Convention for the Conservation of Antarctic Marine Living Resources approximates the Convergence line by joining specified points along parallels of latitude and meridians of longitude.[7] The implementation of the convention is managed through an international commission headquartered in Hobart, Australia, by an efficient system of annual fishing quotas, licenses, and international inspectors on the fishing vessels, as well as satellite surveillance.[8]

The islands situated between 60°S latitude parallel to the south and the Antarctic Convergence to the north and their respective 200-nautical-mile (370 km) exclusive economic zones fall under the national jurisdiction of the countries that possess them: South Georgia and the South Sandwich Islands (United Kingdom), Bouvet Island (Norway), and Heard and McDonald Islands (Australia).

Kerguelen Islands (France; also an EU Overseas territory) are situated in the Antarctic Convergence area, while the Isla Grande de Tierra del Fuego, Falkland Islands, Isla de los Estados, Hornos Island with Cape Horn, Diego Ramírez Islands, Campbell Island, Macquarie Island, Amsterdam and Saint Paul Islands, Crozet Islands, Prince Edward Islands, Gough Island, and Tristan da Cunha group remain north of the Convergence and thus outside the Antarctic region.

Ecology

See also: Antarctic realm, Antarctic microorganism, and Wildlife of Antarctica

Antarctica

Antarctic krill.

A variety of animals live in Antarctica for at least some of the year, including:[9][10]

Chinstrap penguin.

Most of the Antarctica continent is permanently covered by ice and snow, leaving less than 1 percent of the land exposed. There are only two species of flowering plant,

macrofungi.[11]

Sub-Antarctic Islands

Biodiversity among terrestrial flora and fauna is low on the islands: studies have theorized that the harsh climate was a major contributor towards species richness, but multiple correlations have been found with area, temperature, remoteness of islands, and food chain stability. For example, herbivorous insects are poor in number due to low plant richness, and likewise, indigenous bird numbers are related to insects, which are a major food source.[12]

Conservation

Mount Herschel
in Eastern Antarctica

The Antarctic hosts the world's largest

Greenland National Park's 972,000 km2 (375,000 sq mi).[14] (While the Ross Sea Marine Protection Area established in 2016 is still larger at 1.55 million km2, its protection is set to expire in 35 years.[15][16]) To protect the area, all Antarctic ships over 500 tonnes are subject to mandatory regulations under the Polar Code, adopted by the International Maritime Organization (in force since 1 January 2017).[17][18]

Climate change

This section is an excerpt from Climate change in Antarctica.[edit]
NOAA
satellite sensors.

Climate change caused by greenhouse gas emissions from human activities occurs everywhere on Earth, and while Antarctica is less vulnerable to it than any other continent,[19] climate change in Antarctica has already been observed. There has been an average temperature increase of >0.05 °C/decade since 1957 across the continent, although it had been uneven.[20] While West Antarctica warmed by over 0.1 °C/decade from the 1950s to the 2000s and the exposed Antarctic Peninsula has warmed by 3 °C (5.4 °F) since the mid-20th century,[21] the colder and more stable East Antarctica had been experiencing cooling until the 2000s.[22][23] Around Antarctica, the Southern Ocean has absorbed more heat than any other ocean,[24] with particularly strong warming at depths below 2,000 m (6,600 ft)[25]: 1230  and around the West Antarctic, which has warmed by 1 °C (1.8 °F) since 1955.[21]

The warming of Antarctica's territorial waters has caused the weakening or outright collapse of
marine ice sheet instability may cause West Antarctica to contribute tens of centimeters more if it is triggered before 2100.[25]: 1270  With higher warming instability would be much more likely, and could double overall 21st century sea level rise.[26][27][28]
Since the 1970s, the upper cell of the Southern Ocean overturning circulation has strengthened, while the lower cell weakened. These changes have been linked to the melting of the Antarctic ice sheet.
This section is an excerpt from Climate change in Antarctica.[edit]

The fresh

fisheries in the Southern Ocean with a potential collapse of certain marine ecosystems.[32] Furthermore, while many Antarctic species remain undiscovered, there are already documented increases in flora and large fauna such as penguins are already seen struggling to retain suitable habitat. On ice-free land, permafrost thaws, releasing not only greenhouse gases, but also formerly frozen pollution.[33]

The West Antarctic ice sheet is likely to melt completely,
Aurora Basin may collapse over a period of around 2,000 years,[38][39] potentially adding up to 6.4 m (21 ft 0 in) to sea levels.[40] The complete melting and disappearance of the East Antarctic ice sheet would require at least 10,000 years, and it would only occur if global warming reaches 5 °C (9.0 °F) to 10 °C (18 °F).[38][39]

Society

A map of the Antarctic voyages of Anthony de la Roché and others in the Southern Ocean

People

The first recorded sighting of Antarctica is credited to the Spaniard Gabriel de Castilla, who reported seeing distant southern snow-capped mountains in 1603. The first Antarctic land discovered was the island of South Georgia, visited by the English merchant Anthony de la Roché in 1675. Although myths and speculation about a Terra Australis ("Southern Land") date back to antiquity, the first confirmed sighting of the continent of Antarctica is commonly accepted to have occurred in 1820 by the Russian expedition of Fabian Gottlieb von Bellingshausen and Mikhail Lazarev on Vostok and Mirny.

The Australian James Kerguelen Robinson (1859–1914) was the first human born in the Antarctic, on board the sealing ship Offley in the Gulf of Morbihan (Royal Sound then), Kerguelen Island on 11 March 1859.[43][44] The first human born and raised on an Antarctic island was Solveig Gunbjørg Jacobsen born on 8 October 1913 in Grytviken, South Georgia.[45]

Ushuaia in Argentina is the most active gateway to Antarctica.

Emilio Marcos Palma (born 7 January 1978) is an Argentine man who was the first documented person born on the continent of Antarctica at the Esperanza Base.[46] His father, Captain Jorge Palma, was head of the Argentine Army detachment at the base. While ten people have been born in Antarctica since, Palma's birthplace remains the southernmost. In late 1977, Silvia Morella de Palma, who was then seven months pregnant, was airlifted to Esperanza Base, in order to complete her pregnancy in the base. The airlift was a part of the Argentine solutions to the sovereignty dispute over territory in Antarctica. Emilio was automatically granted Argentine citizenship by the government since his parents were both Argentine citizens, and he was born in the claimed Argentine Antarctica
. Palma can be considered to be the first native Antarctican.

geographic South Pole
, with its signpost in the background

The Antarctic region had no

South Georgia Island
.

In December 2009, the growth of tourism, with consequences for both the ecology and the safety of the travellers in its great and remote wilderness, was noted at a conference in New Zealand by experts from signatories to the Antarctic Treaty. The definitive results of the conference were presented at the Antarctic Treaty states' meeting in Uruguay in May 2010.[48]

Time zones

Main article: Time in Antarctica

Because Antarctica surrounds the South Pole, it is theoretically located in all time zones. For practical purposes, time zones are usually based on territorial claims or the time zone of a station's owner country or supply base.[49]

List of offshore islands

A Norwegian cruise ship at Petermann Island with Kyiv Peninsula of Graham Land in the background

North of 60°S latitude

South Georgia Museum, Grytviken

South of 60°S latitude

See also

Notes

  1. ^ The word was originally pronounced without the first /k/, but the spelling pronunciation has become common and is often considered more correct. The pronunciation without the first k sound and the first t sound is however widespread and a typical phenomenon of English in many other similar words too.[1] The "c" was added to the spelling for etymological reasons and then began to be pronounced, but (as with other spelling pronunciations) at first only by less educated people.[2][3]

References

  1. ^ Publishers, HarperCollins. "The American Heritage Dictionary entry: Antarctica". www.ahdictionary.com. Archived from the original on 8 December 2015.
  2. ISBN 978-0-19-920764-0
    .
  3. ^ Harper, Douglas. "Antarctic". Online Etymology Dictionary. Archived from the original on 11 January 2012. Retrieved 16 November 2011.
  4. ^ "Scientific Committee on Antarctic Research website". SCAR. Archived from the original on 14 December 2013.
  5. ^ "The Antarctic Treaty | NSF". www.nsf.gov. National Science Foundation. Archived from the original on 11 May 2013. Retrieved 7 October 2020.
  6. ^ "Commission for the Conservation of Antarctic Marine Living Resources – Department of Agriculture". www.agriculture.gov.au. Archived from the original on 20 September 2020. Retrieved 7 October 2020.
  7. ^ "Convention for the Conservation of Antarctic Marine Living Resources" (PDF). Archived from the original (PDF) on 5 May 2010.
  8. ^ "Schedule of Conservation Measures in Force 2023/24" (PDF). CCAMLR. Archived (PDF) from the original on 8 February 2024. Retrieved 15 April 2024.
  9. ^ "Polar Wildlife". British Antarctic Survey. Natural Environment Research Council. Archived from the original on 1 August 2023.
  10. Commonwealth Scientific and Industrial Research Organisation. Archived from the original
    on 14 December 2013. Retrieved 20 November 2012.
  11. ^ "Plants". British Antarctic Survey. Natural Environment Research Council. Archived from the original on 26 September 2023.
  12. PMID 18811364
    .
  13. ^ "SGSSI Marine Protection Area (Management Plan)" (PDF). Archived from the original (PDF) on 29 October 2016.
  14. ^ "Greenland in figures 2009". Statistics Greenland. 2009. Archived from the original on 28 April 2010.
  15. ^ CCAMLR to create world's largest Marine Protected Area. CCAMLR Website
  16. ^ Slezak, Michael (26 October 2016). "World's largest marine park created in Ross Sea in Antarctica in landmark deal". The Guardian. Archived from the original on 28 October 2016. Retrieved 28 October 2016.
  17. ^ "Shipping in polar waters". IMO. Archived from the original on 2 August 2021. Retrieved 2 August 2021.
  18. ^ "The Polar Code, One Year On". The Maritime Executive. Archived from the original on 2 August 2021. Retrieved 2 August 2021.
  19. S2CID 222179485
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  20. ^ Steig, Eric; Schneider, David; Rutherford, Scott; Mann, Michael E.; Comiso, Josefino; Shindell, Drew (1 January 2009). "Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year". Arts & Sciences Faculty Publications.
  21. ^ a b "Impacts of climate change". Discovering Antarctica. Retrieved 15 May 2022.
  22. S2CID 220261150
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  23. doi:10.1088/1748-9326/acd8d4
    .
  24. PMID 35039511
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  25. ^ a b c d Fox-Kemper, B.; Hewitt, H.T.; Xiao, C.; Aðalgeirsdóttir, G.; Drijfhout, S.S.; Edwards, T.L.; Golledge, N.R.; Hemer, M.; Kopp, R.E.; Krinner, G.; Mix, A. (2021). Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S.L.; Péan, C.; Berger, S.; Caud, N.; Chen, Y.; Goldfarb, L. (eds.). "Chapter 9: Ocean, Cryosphere and Sea Level Change" (PDF). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, USA: 1270–1272.
  26. hdl:20.500.11850/230713
    .
  27. PMID 31110015
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  28. S2CID 218541055
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  29. PMID 29675467
    .
  30. PMID 35013425
    .
  31. ^ Lenton, T. M.; Armstrong McKay, D.I.; Loriani, S.; Abrams, J.F.; Lade, S.J.; Donges, J.F.; Milkoreit, M.; Powell, T.; Smith, S.R.; Zimm, C.; Buxton, J.E.; Daube, Bruce C.; Krummel, Paul B.; Loh, Zoë; Luijkx, Ingrid T. (2023). The Global Tipping Points Report 2023 (Report). University of Exeter.
  32. ^ Logan, Tyne (29 March 2023). "Landmark study projects 'dramatic' changes to Southern Ocean by 2050". ABC News.
  33. S2CID 53093132
    .
  34. ^ Carlson, Anders E; Walczak, Maureen H; Beard, Brian L; Laffin, Matthew K; Stoner, Joseph S; Hatfield, Robert G (10 December 2018). Absence of the West Antarctic ice sheet during the last interglaciation. American Geophysical Union Fall Meeting.
  35. S2CID 266436146
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  36. S2CID 264476246
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  37. S2CID 221885420
    .
  38. ^
    S2CID 252161375
    .
  39. ^ a b c Armstrong McKay, David (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer". climatetippingpoints.info. Retrieved 2 October 2022.
  40. ^
    PMID 33931453
    .
  41. S2CID 13129041. Archived
    (PDF) from the original on 16 February 2020. Retrieved 6 January 2014.
  42. PMID 36088458
    .
  43. ^ Robinson, James (1906). "Appendix B: Log of the Offley". In Cerchi, D. (ed.). Reminiscences (Report). Hobart, Tasmania, AU: Archives Office of Tasmania. pp. 98–99. Archived from the original on 6 February 2012.
  44. ISBN 979-8-88676-403-1
  45. ISBN 9780521424745
    .
  46. ^ "Emilio Palma, argentino y "Adán" de la Antártida | Información General". www.diarioc.com.ar. Archived from the original on 25 February 2021. Retrieved 2 April 2021.
  47. ^ "IAATO tourist statistics 2007/08" (PDF). Archived (PDF) from the original on 1 August 2013. Retrieved 20 July 2009.
  48. The Associated Press
    , 8 December 2009.
  49. ^ National Geographic Spciety (14 August 2012). "South Pole". National Geographic Society. Archived from the original on 28 March 2022. Retrieved 9 April 2022.

Further reading

Main article: Bibliography of Antarctica

External links

90°00′S 00°00′W / 90.000°S -0.000°E / -90.000; -0.000

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