Tristan da Cunha

Tristan da Cunha (English [ ku ː nə trɪstən də ], port. [ tristɐn because kuɲɐ ] ) is a group of islands in the southern Atlantic Ocean, to the next of the same name 98 km ² large main island of Tristan da Cunha still include other smaller islands. On the main island, which is considered the most remote inhabited island in the world, live for about 280 Z. humans. The island group is part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha, where it forms an equal unit, but without - to be divided into more districts - such as St. Helena.

Geography

Tristan da Cunha is located in the South Atlantic some 3,200 kilometers from the Cabo Frio in Brazil and 2800 kilometers from the Cape of Good Hope in South Africa away and is part of the Mid-Atlantic Ridge. To the archipelago of Tristan da Cunha also includes 399 km in a south-southeast direction lying island Gough with a manned weather station and 33 km south-west to uninhabited islands, Iceland Inaccessible, Nightingale Iceland, Iceland and Middle Stoltenhoff Iceland. Nightingale, Middle and Stoltenhoff are often summarized as a Nightingale Islands.

Geology

Tristan da Cunha is the cone-shaped head of a powerful undersea volcano, in the 2060 -meter-high Queen Mary 's Peak and in the 1970 meter high Mount Olav, the two highest elevations of the crater rim, culminates. Geologically interesting is the evolution of the volcanic chain: In the past, the hotspot was located exactly on the spreading axis of the Mid-Atlantic Ridge and the Walvis Ridge. The Paraná and the African side the Etendeka flood basalts were formed on the South American side. If one follows the individual volcanoes back in history, there are two approximate straight lines which meet at an angle of about 120 ° at Tristan da Cunha. Thus, one can well see from this example that there is a big difference between the relative and the absolute plate motion.

The relative plate motion is perpendicular to the mid-ocean ridges, that is, the African plate moves to the east and the South American plate to the west. In absolute terms, the African plate moves, however, to the northeast and the South American Plate to the northwest, whereby the angle formed by the volcanic chain describes can be explained.

History

The island of Tristan da Cunha was discovered in March 1506 by the Portuguese Admiral Tristão da Cunha, who Ilha de Tristão da Cunha christened after himself. He, however, failed to land on the island. He also discovered the south of it lies Nightingale Iceland.

Also in the early 16th century, possibly 1505 or 1506 around 400 km south-east lies Gough Island was sighted by Portuguese navigator Gonçalo Álvares. Inaccessible Iceland, however, was only discovered in 1652 by the crew of the Dutch ship 't night glass.

On August 14, 1816 was the formal annexation of the islands by Britain when British troops occupied the main island. The main motive for the annexation of Tristan da Cunha was to prevent that France could use the island as a base for a rescue attempt of Napoleon Bonaparte from prison on St. Helena.

In 1961, the volcano erupted. The inhabitants of the island were evacuated to England, from where it 1962 again returned to the island.

1834 Tristan da Cunha was with St. Helena, a British Crown Colony, 1981, a British dependent territory in 2002, and finally, based on the Overseas Territories Act, a British overseas territory.