Bellingshausen Island is a small, uninhabited volcanic island in the Southern Thule group of the South Sandwich Islands, in the South Atlantic Ocean. It lies approximately northeast of Cook Island and east of Thule Island. The island is a youthful stratovolcano composed of basaltic andesite, rising to at Basilisk Peak. Its most recent crater, approximately wide and deep, formed during an explosive eruption between 1968 and 1984.
The island was first sighted by James Cook's expedition in 1775, but was not distinguished as a separate island until the First Russian Antarctic Expedition of 1819–1821, led by Fabian Gottlieb von Bellingshausen, after whom it is named. The island was more accurately charted in 1930 by the Discovery Investigations team aboard RRS Discovery II.
Bellingshausen Island is part of the British Overseas Territory of South Georgia and the South Sandwich Islands and is also claimed by Argentina as part of Tierra del Fuego. The island is uninhabited and rarely visited, with no permanent infrastructure.
Geography
Bellingshausen Island is situated at , in the southernmost part of the South Sandwich Islands arc. It is the easternmost and smallest of the three main islands of the Southern Thule group.
The island is dominated by a central volcanic cone that rises steeply on all sides toward Basilisk Peak ().
Geology and volcanism
Bellingshausen Island is part of the South Sandwich volcanic arc, formed by the westward subduction of the South American Plate beneath the South Sandwich Plate. The island is a youthful stratovolcano composed primarily of basaltic andesite lavas and pyroclastic deposits, reflecting the calc-alkaline magma series typical of the arc. A smaller parasitic explosion crater on the southern flank was formed by a phreatic eruption dated to 1975 ± 12 years. Precipitation, primarily as snow, ranges from annually. Chinstrap penguins (Pygoscelis antarcticus) also breed on the island. Other breeding seabirds include southern giant petrels (Macronectes giganteus), snow petrels (Pagodroma nivea), Cape petrels (Daption capense), Wilson's storm petrels (Oceanites oceanicus), black-bellied storm petrels (Fregetta tropica), and kelp gulls (Larus dominicanus). Argentina also claims the island as part of its Tierra del Fuego province, but does not exercise effective control. Access is strictly regulated and requires a permit from the GSGSSI.