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South Orkney Islands

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The South Orkney Islands are a group of islands in the Southern Ocean , about 604 km (375 mi) north-east of the tip of the Antarctic Peninsula and 844 km (524 mi) south-west of South Georgia Island . They have a total area of about 620 km (240 sq mi). The islands are claimed both by Britain (as part of the British Antarctic Territory since 1962, previously as a Falkland Islands Dependency ), and by Argentina as part of Argentine Antarctica . Under the 1959 Antarctic Treaty , sovereignty claims are held in abeyance .

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31-479: Britain and Argentina both maintain bases on the islands. The Argentine base, Orcadas , established in 1904, is sited on Laurie Island . The 11 buildings of the Argentine station house up to 45 people during the summer, and an average of 14 during winter. The British Antarctic Survey base, Signy Research Station , is located on Signy Island and was established in 1947. Initially operated year-round, since 1995/6

62-575: A permanent communication link. The station depended on the Ministry of Agriculture until Argentine Navy relieved the crew with navy personnel on March 3, 1951. Formal transfer occurred on December 23, 1952, when by presidential decree the base was put under the Service of Maritime Hydrography as Destacamento Naval Orcadas ("Orcadas naval Detachment"). Under the Köppen climate classification system,

93-514: A result, the base only averages 483.0 hours of sunshine per year or 13.5% of possible sunshine (possibly the lowest on earth), ranging from a low of 9.3% in January to a high of 22.5% in August. December and January are the least windy months, averaging 19 to 21 km/h (12 to 13 mph) while August and September are the windiest months, averaging more than 25 km/h (16 mph). The base

124-641: A small summer base, Cape Geddes Station in Laurie Island in 1946, replaced by Signy Research Station in Signy Island in 1947. It also had the first radiotelegraph in the continent in 1927. The 11 buildings of the station house up to 65 people during the summer, and an average of 17 during winter. The scientific activities are carried out at the Laboratorio Antártico Mutidisciplinario en Base Orcadas (LABORC),

155-627: Is a frequent occurrence in the base, averaging 110 days. This can vary from year to year with 1987 being the foggiest year when there were 252 days with fog to only 30 days with fog in 1963. Being located in the path of low pressure systems throughout the year, the base experiences high cloud cover, particularly in summer. December and January are the cloudiest months, averaging 29 cloudy days each month. Winters are less cloudy, averaging 20 cloudy days in June and July. Clear days are extremely rare and only occur between May and October, averaging 1–3 days. As

186-417: Is subjected to strong winds throughout the year, with each month averaging 20 days with strong winds (wind speeds above 46 km/h (29 mph)). Occasionally, it can experience gusts above 150 km/h (93 mph). The average annual precipitation is 398.4 mm (15.69 in), which is fairly evenly distributed throughout the year. March is the wettest month while June is the driest month. Due to

217-473: Is the easternmost of the islands. The other main islands are Powell and Signy . Smaller islands in the group include Robertson Islands , the Saddle Islands , and Acuña Island . The total area of the archipelago is about 240 sq mi (620 km), of which about 90 percent is glaciated. The Inaccessible Islands about 15  nmi (17 mi; 28 km) to the west are considered part of

248-569: The Southern Ocean . As a group of islands, the South Orkney Islands are at approximately 60°36′S 45°30′W  /  60.600°S 45.500°W  / -60.600; -45.500 . The archipelago comprises four main islands. Coronation Island is the largest, measuring about 30 mi (48 km) long; its highest point is Mount Nivea which rises to 4,153 ft (1,266 m) above sea level. Laurie Island

279-473: The "Multidisciplinary Antarctic Laboratory at Base Orcadas". In 1903 Dr William S. Bruce 's Scottish National Antarctic Expedition established Omond House , a meteorological station on Laurie Island. During the expedition, however, the crew became stuck in the ice and, unable to sail off, were trapped in the station for the winter. Bruce left the station in December of that year for Buenos Aires to fix

310-462: The 1960s. It has since colonized much of the island and is altering the entire soil ecosystem. Some places they can reach 20,000 individuals per m2. Because it can survive in water, there are concerns that it could reach other islands. The two claimant nations maintain research stations on the islands. Orcadas Base Base Orcadas is an Argentine scientific station in Antarctica , and

341-588: The Director General of the National Postal and Telegraphs Office, Manuel García Fernández. Mossman was left in charge of the expedition, along with William Smith as cook. In 1906, Argentina communicated to the international community the establishment of a permanent base on the South Orkney Islands. On August 26, Haggard sent a letter to Foreign Minister Manuel Montes de Oca reminding him that South Orkneys Islands were British. The British position

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372-649: The Signy Research Station has been open only from November to April each year. Apart from personnel at the bases, there are no permanent human inhabitants on the islands. The South Orkney Islands were discovered in 1821 by two sealers , the American Nathaniel Brown Palmer and the Briton George Powell . The islands were originally named Powell's Group , with the main island named Coronation Island as it

403-537: The South Orkneys. The climate of the South Orkneys is generally cold, wet, and windy. Summers are short and cold (December to March) when the average temperatures reach about 3.5  °C (38.3  °F ) and fall to about −12.8 °C (9 °F) in July. The all time temperature range at Orcadas Base is between 12 and −44 °C (53.6 and −47.2 °F). The highest temperature recorded at Signy Research Station

434-640: The appointed personnel back to the station. Bruce had informed the British officer William Haggard of his intentions in December 1903. On 29 December, Haggard sent a note to the Argentine Foreign Minister, José Terry, ratifying the terms of Bruce's proposition. Roca submitted the matter to the Oficina Meteorológica Nacional (National Office of Meteorology) who advised him to accept the offer. On January 2, 1904,

465-474: The cold climate and exposure to maritime westerlies, snowfall occurs frequently throughout the year. Based on the 1961–1990 period, the base averages 227 days with snow, with February having the least days with snow (averaging 14 days with snow) and May having the most days with snow (averaging 22 days). Orcadas Base is the site of the Destacamento Lighthouse , a navigation light mounted on

496-465: The first permanently inhabited base in Antarctica. The nearest Argentine port is Ushuaia , which is 1,502 km (811 nmi) away. The base has 11 buildings and four main topics of research: continental glaciology, seismology, sea-ice-zone glaciology (since 1985) and meteorological observations (since 1903). Orcadas was the only station on the islands for 40 years until the British established

527-760: The harsh conditions, the islands do support vegetation and constitute the South Orkney Islands tundra ecoregion . All islands lie in the cold seas below the Antarctic Convergence . These areas support tundra vegetation consisting of mosses , lichens and algae , while seabirds, penguins and seals feed in the surrounding waters. The littoral zone of the South Orkneys is biologically either lifeless or very poor. Amphipods and planarians exist under rocks, along with various algaes, chitons , and some gastropods . With increasing water depth, life becomes more varied: starfish appear beyond 2–3 metres along with sponges, urchins, and ascidians . At 8–10 metres,

558-603: The installations were accepted through a presidential decree. The Scotia sailed back for Laurie Island on 14 January 1904 carrying on board Luciano H. Valette, from the Office of Zoology of the Ministry of Agriculture, Edgard C. Szmula, employee of the National Meteorological Office, and Hugo Acuña, from the Ministry of Livestock, who was also designated Postal Chief of the Orkney Islands by

589-618: The islands, reverted some of Weddell's name changes, and established a meteorological station, which was sold to the Argentine Government upon his departure in 1904. This base, renamed Orcadas in 1951, is still in operation today and is thus the oldest research station continuously staffed in the Antarctic. In 1908, the United Kingdom declared sovereignty over various Antarctic and South American territories "to

620-550: The islands, which influences the climate. Mean monthly temperatures range from −9.4 °C (15.1 °F) in June to 1.0 °C (33.8 °F) in February. In summer, the average high is 2.7 °C (36.9 °F) while the average low is −1.1 °C (30.0 °F). During winter, the average high is −4.9 °C (23.2 °F) while the average low is −13.0 °C (8.6 °F). Temperatures can occasionally rise above freezing during winter. When low pressure systems pass to

651-637: The naming of the islands. (Incidentally, the South Shetland Islands , discovered in 1819 by William Smith , are roughly the same latitude south as the Shetland Islands are north: 62°S vs 60°N.) Subsequently, the South Orkney Islands were frequently visited by sealers and whalers , but no thorough survey was done until the expedition of William Speirs Bruce on the Scotia in 1903, which overwintered at Laurie Island. Bruce surveyed

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682-734: The oldest of the stations in Antarctica still in operation. It is located on Laurie Island , one of the South Orkney Islands ( Spanish : Islas Orcadas del Sur ), at 4 meters (13 ft) above sea level and 170 meters (558 ft) from the coastline. Established by the Scottish National Antarctic Expedition in 1903 and transferred to the Argentine government in 1904, the base has been permanently populated since, being one of six Argentine permanent bases in Argentina's claim to Antarctica , and

713-470: The ship and obtain supplies, leaving meteorologist Robert C. Mossman in charge of the base to continue the observations. Bruce offered to the Government of President Julio Argentino Roca the transfer of the station and instruments for the sum of 5.000 pesos , on the condition that the government committed itself to the continuation of the scientific mission. He also offered to transport in his ship

744-624: The south of the 50th parallel of south latitude, and lying between the 20th and the 80th degrees of west longitude", including the South Orkney Islands. The Islands were subsequently administered as part of the Falkland Islands Dependencies . A biological research station on Signy Island was built in 1947 by the British Antarctic Survey , and was staffed year-round until 1996, when the Station staffing

775-430: The south of the base, they can result in exceptionally mild temperatures, with the highest temperature recorded being 15.2 °C (59.4 °F) in 1987. However, when this occurs, the weather is stormy and cloudy with reduced visibility. In contrast, when low pressure systems pass to the north, it results in cold and dry conditions with good visibility, causing temperatures to fall to −44.0 °C (−47.2 °F). Fog

806-584: The station is located under a tundra climate ( ET ), very close to an ice cap climate ( EF ). The base is influenced by the cold Antarctic Circumpolar Current that runs past the Weddell Sea and the strong westerly winds, creating a colder climate than the coastal areas in the northwestern parts of the Antarctic Peninsula . Weather conditions can vary widely from year to year and day to day since low pressure systems frequently pass through

837-417: The variety of starfish increases along with the general biomass, and below 30 metres there are vast colonies of these creatures. Two penguin species, Chinstrap ( Pygoscelis antarctica ) and Adélie ( Pygoscelis adeliae ), are present on land. On Signy Island a parthenogenetic flightless midge originally from South Georgia , Eretmoptera murphyi , was accidentally introduced during a botany experiment in

868-429: Was 19.8 °C (67.6 °F) on 30 January 1982, which is the highest temperature recorded anywhere south of 60°S . The seas around the islands are ice-covered from late April to November. South Orkney Trough ( 60°0′S 45°0′W  /  60.000°S 45.000°W  / -60.000; -45.000 ) is an undersea trough named in association with the South Orkney Islands and approved 10/77 (ACUF 177). Despite

899-510: Was reduced to 8–10 personnel who remained only during the southern hemisphere summer (November to April each year). In 1962, the islands became part of the newly established British Antarctic Territory . The Argentine claim to the islands dates from 1925. It was originally justified by the Argentine occupation of the Laurie Island base and later subsumed into a wider territorial claim . The islands are situated at latitudes about 60°30' to 60°48' S and longitudes 44°25' to 46°43' W in

930-568: Was that Argentine personnel was granted permission only for the period of one year. Argentine government ignored the note, "considering it out of time". On March 30, 1927, naval non-commissioned officer Emilio Baldoni established the first radio telegraph link with Ushuaia. Up to that point, the Orcadas Base remained isolated from the rest of the world until the yearly relief arrived. The radio station (coded LRT in Argentina) allowed for

961-467: Was the year of the coronation of King George IV . In 1823, James Weddell visited the islands, gave the archipelago its present name (after the Orkney Islands in the north of Scotland ) and also renamed some of the islands. The South Orkney Islands are located at roughly the same latitude south as the Orkney Islands are north (60°S vs 59°N), although it is not known if this was a factor behind

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