Tristan da Cunha

Tristan da Cunha is part of the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha, and has been occupied since around 1816. Tristan da Cunha claims to be the most remote island community in the world ; the nearest land being South Africa, some 2816 km away.

Most of the population of around 280 live in the town of Edinburgh of the Seven Seas on the north coast of the island, which is approximately 11 km long and 9 km wide. It is entirely volcanic in origin comprising basanitic and phonolitic lava flows.

The most recent lava flow was erupted from St. Mary's Peak over four months from 1961–1962. The eruption was preceeded by two months of tremors felt by the population. The islanders evacuated to nearby Inaccessible Island, and were later temporarily evacuated to England, returning to the island in 1963.

View of Tristan da Cunha Island on a clear and calm day
Photo of the settlement, Edinburgh of the Seven Seas.

A sequence of volcanic earthquakes began suddenly on 29 July 2004, the largest of which was magnitude 4.8 and fresh pumice was washed up on some of the beaches.

The BGS staff carried out rapid seismic and volcanic analysis and deduced that a submarine eruption had taken place 37–53 km south-south-east of the island.

The BGS co-funded a multi-disciplinary PhD project in 2008 on volcanic risk reduction on Tristan da Cunha.


For more information contact Dr Anna Hicks