Largest Islands of Antarctica

Geography

As a group of islands, the South Shetland Islands are located at 62°0′S 58°0′W. They are within the region 61° 00'–63° 37' South, 53° 83'–62° 83' West. The islands lie 940 km (510 nmi) south of the Falkland Islands, and between 93 km (50 nmi) (Deception Island) and 269 km (145 nmi) (Clarence Island) northwest and north from the nearest point of the Antarctic continent, Graham Land.

The South Shetlands consist of 11 major islands and several minor ones, totalling 3,687 km2 (1,424 sq mi) of land area. Between 80 and 90% of the land area is permanently glaciated. The highest point on the island chain is Mount Foster on Smith Island at 2,025 m (6,644 ft) above sea level at 2-meter spatial resolution.

History

The islands were discovered by British mariner William Smith, in William, in 1819, although Dutch mariner Dirck Gerritsz in 1599 or Spanish Admiral Gabriel de Castilla in 1603 might have sighted the South Shetlands, or North or South American sealers might have visited the archipelago before Smith. Smith's discovery was well documented and had wider historical implications beyond its geographic significance.

Chilean scientists have claimed that Amerinds have visited the islands, due to stone artifacts recovered from bottom-sampling operations in Admiralty Bay, King George Island, and Discovery Bay, Greenwich Island; however, the artifacts – two arrowheads – were later found to have been planted.

Geology

In the archipelago, the Buckle, Sturge and Young Islands are examples of stratovolcanoes. Strong earthquakes very close to the islands are rare, but tremors of moderate strength do occur over the Pacific-Antarctic Ridge, Macquarie triple junction and Pacific Rim between the Balleny Islands and Macquarie Island. Other earthquakes occur near the Southeast Indian Ridge and Balleny fracture zone, including a magnitude 8.1 earthquake in 1998 that struck just over 700 km (430 mi) west-northwest of the islands which changed the pattern of seismicity in a wide area around the islands.

It is possible that these islands are still volcanically active. The Brown Peak volcano may have had an eruption in 2001, based on satellite observation.

Geography and climate

The islands are situated at latitudes about 60°30' to 60°48' S and longitudes 44°25' to 46°43' W in the Southern Ocean. As a group of islands, the South Orkney Islands are at approximately 60°36′S 45°30′W.

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 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 km2), of which about 90 percent is glaciated.

History

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 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 the naming of the islands.

Location

Joinville Island lies in Graham Land to the east of the tip of Trinity Peninsula, which is itself the tip of the Antarctic Peninsula.

D'Urville Island is to the north, Danger Islands to the east and Dundee Island to the west.

Northern features include Cape Kinnes, Boral Point, King Point and Fitzroy Point.

Southern features include Mount Percy, Mount Quilmes, Tay Head and Moody Point.

Location

James Ross Island is separated from Trinity Peninsula, at the tip of the Antarctic Peninsula to the northwest, by the Prince Gustav Channel.

Vega Island is to the north of the island, separated from James Ross Island by the Herbert Sound.

The island was connected to the Antarctic mainland by an ice shelf until 1995, when the ice shelf collapsed, making the Prince Gustav Channel passable for the first time.

Mendel Polar Station, the first Czech Antarctic Base, is located on the island.

Location

Stefansson Strait is on the Wilkins Coast of Palmer Land, beside the Weddell Sea to the east.

It is east of the Eternity Range, north of Hughes Ice Piedmont and south of Scripps Heights and Casey Inlet.

The south of the strait is at the north side of the mouth of Anthony Glacier, which flows eastward past the Engel Peaks and Mount Martin to enter the sea north of Lewis Point.

Features of the coast to the west of the strait, from south to north, include Rhino Rock, Cape Rymill, Briesemeister Peak and Cape Reichelderfer.

The Binghy Glacier flows east between De Busk Scarp and Le Feuvre Scarp to enter the trait north of Cape Reichelderfer.

History

Berkner Island was discovered by members of the United States-International Geophysical Year party from Ellsworth Station during the 1957–1958 season. It was named by the United States Advisory Committee on Antarctic Names after American physicist Lloyd Berkner, engineer with the Byrd Antarctic Expedition (1928–1930).

Since 1990, Berkner Island has been a jumping-off point for a number of long-distance polar expeditions. Ben Saunders has planned an unsupported journey from the island to the South Pole and back, and it was the start point of Henry Worsley's attempt to cross the Antarctic in 2015–16.

History

On 6 February 2024, for the first time since 2017, British Royal Navy personnel from HMS Protector landed on the island in an effort to clear three tonnes of waste and abandoned equipment from the 1980s antarctic expedition.

Geology

The Brabant Island Tectonic Block includes up to 2000 m of basaltic-andesitic lavas and volcaniclastics, possibly corresponding to the Lower Cretaceous Antarctic Peninsula Volcanic Group of the Danco Coast. This group is intruded by a granodiorite sill and Early Eocene hypabyssal dykes. Late Tertiary to Pleistocene basaltic lavas uncomformably overlay this complex.

Location

The north shore of the King Peninsula is the western end of the Eights Coast, while the west and southern shore is in the Walgreen Coast.

Peacock Sound is to the north, completely filled by the western part of the Abbot Ice Shelf.

Burke Island is in the sea to the west. The Waite Islands are off Cape Waite, the northwest extremity of the peninsula.

Marelli Glacier drains northeast from the peninsula into the Abbot Ice Shelf.

Geography

Livingston Island is situated in West Antarctica, 110 km (68 mi) northwest of Cape Roquemaurel on the Antarctic mainland, 809 km (503 mi) south-southeast of Cape Horn in South America, 796 km (495 mi) southeast of the Diego Ramírez Islands (the southernmost land of South America), 1,063 km (661 mi) due south of the Falkland Islands, 1,571 km (976 mi) southwest of South Georgia Islands, and 3,040 km (1,889 mi) from the South Pole.

The island is part of the South Shetlands archipelago, an islands chain extending 510 km (317 mi) in east-northeast to west-southwest direction, and separated from the nearby Antarctic Peninsula by Bransfield Strait, and from South America by the Drake Passage.

History

It was only during the nineteenth century that any land was discovered in what is now the ‘political’ territory of Antarctica, and that land happened to be Livingston Island. The English merchant William Smith in his brig William, while sailing to Valparaíso in early 1819, strayed from his route south of Cape Horn and on 19 February sighted Williams Point, the northeast extremity of Livingston. That was the first land ever discovered south of 60° south latitude, in what is now the Antarctic Treaty area.

It is noteworthy that navigation round Fire Land spanned over two hundred years, yet no one saw the coasts of New Shetland. In 1616 the Dutch mariners Lemaire and Schouten found a strait between Fire Land and Staten Land named after Lemaire.

Climate

The climate of Livingston is polar tundra under the Köppen-Geiger climate classification system. Climatic conditions are influenced by the following specific factors: the island's location in the narrowest part of the Southern Ocean (less than 600 km between the Antarctic Convergence and the Antarctic Peninsula); the relatively small amplitude of water temperatures in the surrounding sea; the local relief including Tangra Mountains, one of the highest mountain ranges in the archipelago that contributes to shaping the local atmospheric circulation; and the ice cap of the island. Surface air temperature decreases with increasing altitudes, which in the interior of eastern Livingston Island reach 550 m at the centrally located Wörner Gap and over 1400 m at the crest of Tangra Mountains.

Tourism

Antarctic shipborne tourism was initiated in the 1957/58 season with four cruises operated by Chile and Argentina in the South Shetland Islands. Since then the number of tourists visiting Antarctica has grown to several tens of thousands annually. Over 95% of them tour the South Shetlands and the nearby Antarctic Peninsula. Hannah Point on the south coast of Livingston, Half Moon Island off its east coast, Aitcho Islands just north of Greenwich Island, and Deception Island are among the most popular destinations.

Geography

Elephant Island marks the western end of the South Scotia Ridge. The island is oriented approximately east–west, with a maximum elevation of 973 m (3,192 ft) at Mount Pendragon. The weather is normally foggy with much snow, and winds can reach 160 km/h (100 mph).

Significant named features are Cape Yelcho, Cape Valentine and Cape Lookout at the northeastern and southern extremes, and Point Wild, a spit on the north coast. The Endurance Glacier is the main discharge glacier.

History

The First Russian Antarctic expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev on the 985-ton sloop-of-war Vostok ("East") and the 530-ton support vessel Mirny ("Peaceful") discovered Elephant Island on 29 January 1821 and named it Mordvinov Island (Остров Мордвинова) in honour of Admiral Mordvinov.

The island was the refuge of explorer Ernest Shackleton and his crew in 1916 following the loss of their ship Endurance in the pack ice of the Weddell Sea. The crew of 28 reached Cape Valentine on Elephant Island after months spent drifting on ice floes and a harrowing crossing of the open ocean in small lifeboats.

Geology

Elephant Island is part of the Scotia metamorphic complex, which was created by Cretaceous sea floor sediments being scraped off and metamorphosed at the Scotia subduction zone. The resulting rocks are phyllites, blueschists and greenschists typical of an accretionary wedge, with increased metamorphism from northeast to southwest. These rocks are at the surface here because of uplift along the Shackleton Fault Zone where it meets the South Scotia Ridge. This complex is very similar in age and rock types to those of coastal California, including Catalina Island and the Big Sur coast.

Elephant Island is the type locality for phosphate mineral spheniscidite.

History

Charcot Island was discovered on 11 January 1910 by the French Antarctic Expedition under Jean-Baptiste Charcot, who, at the insistence of his crew and the recommendation of Edwin S. Balch and others, named it Charcot Land. He did so with the stated intention of honoring his father, Jean-Martin Charcot, a famous French physician. The insularity of Charcot Land was proved by Sir Hubert Wilkins, who flew around it on 29 December 1929.

The ice bridge holding the Wilkins Ice Shelf to the Antarctic coastline and Charcot Island was 40 kilometres (25 mi) long but only 500 metres (1,640 ft) wide at its narrowest point – in 1950 it was 100 kilometres (62 mi) It shattered in April 2009 over an area measuring 20.1 by 2.4 kilometres (12.5 by 1.5 mi).

Geology

The Anvers-Melchior Islands Tectonic Block includes the northwest portion of Anvers Island and the Melchior Islands offshore. The block is bounded on the southeast by the SW-NE trending strike-slip Fournier Fault. The block is composed of a volcanic suite which may correspond to the Antarctic Peninsula Volcanic Group. Granite, diorite, and tonalite plutons indicate three phases of intrusion dated at 68-54 Ma, 34 Ma, and 21-20 Ma. Two distinct systems of dykes are present, possibly of Tertiary age. The southeast portion of Anvers Island is part of the Neumayer Channel Tectonic Block.

Geography

Thurston Island is separated from the mainland by Peacock Sound, which is occupied by the western portion of Abbot Ice Shelf.

Sherman Island, Carpenter Island and Dustin Island in Seraph Bay lie to the south of Thurston Island.

Peaks in that range include, from west to east, Landfall Peak, Mount Lopez, Mount Caldwell, Mount Kazukaitis, Mount Simpson, Mount Noxon, Mount Leech, Mount Hubbard, Smith Peak, Mount Borgesen, Guy Peaks, Mount Hawthorne, Mount Bramhall, Zuhn Bluff and Parker Peak.

The northwest side of the island consists of a series of capes, peninsulas and inlets.

History

Thurston Island was discovered by Rear Admiral Richard E. Byrd and members of the United States Antarctic Service (USAS) in a flight from the Bear on 27 February 1940.

Byrd named it for W. Harris Thurston, a New York textile manufacturer, designer of the windproof "Byrd Cloth" and contributor to the expedition.

Originally charted as a peninsula, the feature was found to be an island by the USN Bellingshausen Sea Expedition in February 1960.

On 30 December 1946, Thurston Island was the site of Antarctica's first fatal plane crash. A Martin PBM-5 Mariner (59098) of the US Navy with the Byrd expedition hit a ridge and burned on the island, killing 3 of the 9 occupants. The 6 survivors were rescued 13 days later.

Location

The Abbott Ice Shelf extends to the south of Thurston Island, Dustin Island, McNamara Island, and Farwell Island all of which lie between the ice shelf and the Bellingshausen Sea.

The Demas Ice Tongue extends into the Amundsen Sea from the west end of the ice shelf.

Islands embedded in the Abbott Ice Shelf include the Trice Islands, Sherman Island, Carpenter Island, Johnson Island, Lepley Nunatak and Dendtler Island.

Cape Waite on King Peninsula lies at its western end, and Pfrogner Point on Fletcher Peninsula is at its eastern end.

Fletcher Peninsula separates it from the Venable Ice Shelf to the east.

Location

The islands of the Marshall Archipelago are scattered throughout the Sulzberger Ice Shelf.

The landward side of the ice shelf extends southeast from Howard Heights to McKinley Peak, then runs northeast to the Denfeld Mountains and then runs northwest along the southern edge of the Guest Peninsula.

The seaward side extends in a generally northeast direction from the tip of the Reeves Peninsula to the tip of the Guest Peninsula.

Islands in the southwest include Kizer Island, Cronenwett Island, Orr Island, Grinder Island, Madden Island, Moody Island, Przybyszewski Island and Steventon Island.

Islands in the southeast include Thode Island, Benton Island, Gould Island, Spencer Island, Nolan Island and Kramer Island.