المعرفة

جزيرة هيرد وجزر ماكدونالد

(تم التحويل من Heard Island and McDonald Islands)

The Territory of Heard Island and McDonald Islands[1][2] (HIMI[3]) is an Australian external territory comprising a volcanic group of barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size is 372 km2 (144 sq mi) in area and it has 101.9 km (63 mi) of coastline. Discovered in the mid-19th century, the islands have been an Australian territory since 1947 and contain the country's two only active volcanoes. The summit of one, Mawson Peak, is higher than any mountain on the Australian mainland. The islands lie on the Kerguelen Plateau in the Indian Ocean.

Territory of Heard and McDonald Islands
ISS018-E-038182 lrg.jpg
Satellite image of the southern tip of Heard Island. Cape Arkona is seen on the left side of the image, with Lied Glacier just above and Gotley Glacier just below. Big Ben Volcano and Mawson Peak are seen at the lower right side of the image.
Australia in its region (Heard Island and McDonald Islands special).svg
الجغرافيا
الموقعIndian Ocean
الجزر الرئيسية2
المساحة368 km2 (142 sq mi)
أعلى منسوب2٬745 m (9٬006 ft)
أعلى نقطةMawson Peak
الإدارة
السكان
التعدادUninhabited (2011)
موقع تراث عالمي لليونسكو
السماتNatural: viii, ix
مراجع577
التدوين1997 (21st Session)
المساحة658,903 ha

The islands are among the most remote places on Earth: They are located approximately 4,099 km (2,547 mi) southwest of Perth,[4] 3,845 km (2,389 mi) southwest of Cape Leeuwin, Australia, 4,200 km (2,600 mi) southeast of South Africa, 3,830 km (2,380 mi) southeast of Madagascar, 1,630 km (1,010 mi) north of Antarctica, and 450 km (280 mi) southeast of the Kerguelen Islands.[5] The islands are currently uninhabited.

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Geography

المقالة الرئيسية: Geography of the Heard and McDonald Islands
انظر أيضاً: Heard Island glaciers
 
Heard Island and McDonald Islands
 
Heard Island

Heard Island, by far the largest of the group, is a 368-square-kilometre (142 sq mi) mountainous island covered by 41 glaciers[6] (the island is 80% covered with ice[1]) and dominated by the Big Ben massif. It has a maximum elevation of 2,745 metres (9,006 ft) at Mawson Peak, the historically active volcanic summit of Big Ben. A July 2000 satellite image from the University of Hawaii's Institute of Geophysics and Planetology (HIGP) Thermal Alert Team showed an active 2-kilometre-long (1.2 mi) and 50- to 90-metre-wide (164–295 ft) lava flow trending south-west from the summit of Big Ben.[7]


Climate

 
Vortex shedding as winds pass Heard Island resulted in this Kármán vortex street in the clouds

The islands have an Antarctic climate, tempered by their maritime setting. The weather is marked by low seasonal and daily temperature ranges, persistent and generally low cloud cover, frequent precipitation and strong winds. Snowfall occurs throughout the year. Monthly average temperatures at Atlas Cove (at the northwestern end of Heard Island) range from 0.0 to 4.2 °C (32.0 to 39.6 °F), with an average daily range of 3.7 to 5.2 °C (38.7 to 41.4 °F) in summer and −0.8 to 0.3 °C (30.6 to 32.5 °F) in winter. The winds are predominantly westerly and persistently strong. At Atlas Cove, monthly average wind speeds range between around 26 and 33.5 km/h (16.2 and 20.8 mph). Gusts in excess of 180 km/h (110 mph) have been recorded. Annual precipitation at sea level on Heard Island is in the order of 1,300 to 1,900 mm (51.2 to 74.8 in); rain or snow falls on about 3 out of 4 days.[8]

Meteorological records at Heard Island are incomplete.

بيانات مناخ Heard Island, 12 m asl (1981–2010 normals)
الشهر يناير فبراير مارس أبريل مايو يونيو يوليو أغسطس سبتمبر اكتوبر نوفمبر ديسمبر العام
العظمى القياسية °س (°ف) 20.1
(68.2) 		18.0
(64.4) 		19.9
(67.8) 		20.4
(68.7) 		19.3
(66.7) 		14.0
(57.2) 		15.0
(59) 		15.4
(59.7) 		16.8
(62.2) 		16.4
(61.5) 		14.6
(58.3) 		19.2
(66.6) 		20٫4
(68٫7)
العظمى المتوسطة °س (°ف) 6.4
(43.5) 		6.5
(43.7) 		6.3
(43.3) 		5.3
(41.5) 		3.7
(38.7) 		2.3
(36.1) 		2.2
(36) 		2.2
(36) 		2.2
(36) 		3.3
(37.9) 		4.1
(39.4) 		5.4
(41.7) 		4٫16
(39٫49)
المتوسط اليومي °س (°ف) 4.7
(40.5) 		4.8
(40.6) 		4.6
(40.3) 		3.6
(38.5) 		2.2
(36) 		0.9
(33.6) 		0.5
(32.9) 		0.4
(32.7) 		0.5
(32.9) 		1.5
(34.7) 		2.4
(36.3) 		3.8
(38.8) 		2٫49
(36٫49)
الصغرى المتوسطة °س (°ف) 3.0
(37.4) 		3.1
(37.6) 		2.8
(37) 		1.9
(35.4) 		0.7
(33.3) 		-0.6
(30.9) 		-1.1
(30) 		-1.4
(29.5) 		-1.1
(30) 		-0.2
(31.6) 		0.7
(33.3) 		2.1
(35.8) 		0٫83
(33٫49)
الصغرى القياسية °س (°ف) -0.5
(31.1) 		0.2
(32.4) 		-1.7
(28.9) 		-2.9
(26.8) 		-4.8
(23.4) 		-7.2
(19) 		-6.2
(20.8) 		-11.5
(11.3) 		-8.6
(16.5) 		-7.1
(19.2) 		-6.2
(20.8) 		-0.7
(30.7) 		−11٫5
(11٫3)
Source #1: Météo climat stats[9]
Source #2: Météo Climat [10]


History

 
Heard Island 1887 by Henry Wood Elliott[11]

Neither island-cluster had recorded visitors until the mid-1850s.

An American sailor, John Heard, on the ship Oriental, sighted Heard Island on 25 November 1853, en route from Boston to Melbourne. He reported the discovery one month later and had the island named after him. William McDonald aboard the Samarang discovered the nearby McDonald Islands six weeks later, on 4 January 1854.[12]

No landing took place on the islands until March 1855, when sealers from the Corinthian, led by Erasmus Darwin Rogers, went ashore at a place called Oil Barrel Point. In the sailing period from 1855 to 1880 a number of American sealers spent a year or more on the island, living in appalling conditions in dark smelly huts, also at Oil Barrel Point. At its peak the community consisted of 200 people. By 1880 sealers had wiped out most of the seal population and then left the island. In all the islands furnished more than 100,000 barrels of elephant-seal oil during this period.

A number of wrecks have occurred in the vicinity of the islands. There is also a discarded building left from John Heard's sealing station which is situated near Atlas Cove.

The first recorded landing on McDonald Island was made by Australian scientists Grahame Budd and Hugh Thelander on 12 February 1971, using a helicopter.[13][14]

The islands have been a territory of Australia since 1947, when they were transferred from the UK.[1] The archipelago became a World Heritage Site in 1997.


Retreat of Heard Island glaciers

انظر أيضاً: Retreat of glaciers since 1850 and Glacier mass balance

Heard Island is a heavily glacierized, subantarctic volcanic island located in the Southern Ocean, roughly 4000 kilometers southwest of Australia. 80% of the island is covered in ice, with glaciers descending from 2400 meters to sea level.[15] Due to the steep topography of Heard Island, most of its glaciers are relatively thin (averaging only about 55 meters in depth).[16] The presence of glaciers on Heard Island provides an excellent opportunity to measure the rate of glacial retreat as an indicator of climate change.[17]

Administration and economy

 
Heard Island, 1929.

The United Kingdom formally established its claim to Heard Island in 1910, marked by the raising of the Union Flag and the erection of a beacon by Captain Evensen, master of the Mangoro. Effective government, administration and control of Heard Island and the McDonald Islands was transferred to the Australian government on 26 December 1947 at the commencement of the first Australian National Antarctic Research Expedition (ANARE) to Heard Island, with a formal declaration that took place at Atlas Cove. The transfer was confirmed by an exchange of letters between the two governments on 19 December 1950.

he islands' only natural resource is fish; the Australian government allows limited fishing in the surrounding waters.[1] Despite the lack of population, the islands have been assigned the country code HM in ISO 3166-1 (ISO 3166-2:HM) and therefore the Internet top-level domain .hm. The time zone of the islands is UTC+5.[18]

See also


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References

  1. ^ أ ب ت ث "Heard Island and McDonald Islands". CIA World Factbook. Retrieved 4 January 2009.
  2. ^ UNESCO. "Heard and McDonald Islands". Retrieved 31 January 2015.
  3. ^ Commonwealth of Australia. "About Heard Island – Human Activities". Archived from the original on 18 October 2006. Retrieved 21 October 2006.
  4. ^ "Cocky Flies, Geoscience Australia". Archived from the original on 24 ديسمبر 2008. Retrieved 29 مارس 2016.
  5. ^ "Distance Between Cities Places On Map Distance Calculator". distancefromto.net. Retrieved 29 March 2016.
  6. ^ Ken Green and Eric Woehler (2006). Heard Island: Southern Ocean Sentinel. Surrey Beatty & Sons. pp. 28–51.
  7. ^ Heard Island Geology Archived 12 سبتمبر 2009 at the Wayback Machine
  8. ^ HIMI official website.
  9. ^ "Moyennes 1961-1990 Australie (Ile Heard)" (in الفرنسية). Retrieved 11 November 2019.
  10. ^ "Météo Climat stats for Ile Heard". Météo Climat. Retrieved 11 November 2019.
  11. ^ Goode, George Brown (1887) Fisheries and Fishery Industries of the United States, (Washington, DC: Government Printing Office, 1887).
  12. ^ Mills, William James (2003). Exploring Polar Frontiers: A Historical Encyclopedia. ISBN 9781576074220.
  13. ^ Cerchi, Dan (1 August 2009). "SIOE 2002: Heard I. & The McDonald Is". www.cerchi.net. Archived from the original on 26 April 2012.
  14. ^ "Gazetteer - AADC Name Details - Australian Antarctic Data Centre". Australian Antarctic Data Centre. Archived from the original on 2011-04-06. Retrieved 29 March 2016 – via Internet Archive.
  15. ^ Ian F. Allison; Peter L. Keage (1986). "Recent changes in the glaciers of Heard Island". Polar Record. 23 (144): 255–272. doi:10.1017/S0032247400007099. {{cite journal}}: Unknown parameter |lastauthoramp= ignored (|name-list-style= suggested) (help)
  16. ^ Andrew Ruddell (2010-05-25). "Our subantarctic glaciers: why are they retreating?". Glaciology Program, Antarctic CRC and AAD. Archived from the original on 2 October 2009. Retrieved 5 June 2010.
  17. ^ "'Big brother' monitors glacial retreat in the sub-Antarctic". Kingston, Tasmania, Australia: Australian Antarctic Division. 8 October 2008. Archived from the original on 30 September 2009. Retrieved 7 June 2010.
  18. ^ "Heard Island and McDonald Islands :: Time Zones". timegenie.com. Retrieved 29 March 2016.

Further reading

  • Commonwealth of Australia (2014). Heard Island and McDonald Islands Marine Reserve Management Plan 2014–2024, Department of the Environment, Canberra. ISBN 978-1876934-255. Available at http://heardisland.antarctica.gov.au/
  • Australian Government. (2005) Heard Island and McDonald Islands Marine Reserve Management Plan. Australian Antarctic Division: Kingston (Tas). ISBN 1-876934-08-5.
  • Green, Ken and Woehler Eric (eds). (2006) Heard Island: Southern Ocean Sentinel. Chipping Norton: Surrey Beatty and Sons. ISBN 9780949324986.
  • Scholes, Arthur. (1949) Fourteen men; story of the Australian Antarctic Expedition to Heard Island. Melbourne: F.W. Cheshire.
  • Smith, Jeremy. (1986) Specks in the Southern Ocean. Armidale: University of New England Press. ISBN 0-85834-615-X.
  • LeMasurier, W. E. and Thomson, J. W. (eds.). (1990) Volcanoes of the Antarctic Plate and Southern Oceans. American Geophysical Union. ISBN 0-87590-172-7.

External links

 
Wikivoyage has a travel guide for جزيرة هيرد وجزر ماكدونالد.


Coordinates: 53°06′00″S 73°31′00″E / 53.10000°S 73.51667°E / -53.10000; 73.51667

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