Saint Helena, Ascension, and Tristan da Cunha: Geography#
| Location | islands in the South Atlantic Ocean, about midway between South America and Africa; Ascension Island lies 700 nm northwest of Saint Helena; Tristan da Cunha lies 2,300 nm southwest of Saint Helena |
|---|---|
| Geographic Coordinates | Saint Helena: 15 57 S, 5 42 W Ascension Island: 7 57 S, 14 22 W Tristan da Cunha island group: 37 15 S, 12 30 W |
| Area | total: 308 sq km land: Saint Helena Island 122 sq km; Ascension Island 88 sq km; Tristan da Cunha island group 98 sq km water: 0 sq km |
| Land boundaries | 0 km |
| Coastline | Saint Helena: 60 km Ascension Island: NA Tristan da Cunha: 40 km |
| Elevation Extremes | highest point: Queen Mary's Peak on Tristan da Cunha 2,060 m; Green Mountain on Ascension Island 859 m; Mount Actaeon on Saint Helena Island 818 m lowest point: Atlantic Ocean 0 m Atlantic Ocean |
| Highest Mountains | |
| Terrain | the islands of this group result from volcanic activity associated with the Atlantic Mid-Ocean Ridge Saint Helena: rugged, volcanic; small scattered plateaus and plains Ascension: surface covered by lava flows and cinder cones of 44 dormant volcanoes; ground rises to the east Tristan da Cunha: sheer cliffs line the coastline of the nearly circular island; the flanks of the central volcanic peak are deeply dissected; narrow coastal plain lies between The Peak and the coastal cliffs |
| Natural Hazards | active volcanism on Tristan da Cunha volcanism: the island volcanoes of Tristan da Cunha (elev. 2,060 m) and Nightingale Island (elev. 365 m) experience volcanic activity; Tristan da Cunha erupted in 1962 and Nightingale in 2004 |
| Natural Resource | fish, lobster |
| Land Use | arable land: 10.26% permanent crops: 0% other: 89.74% (2011) |
| Climate | Saint Helena: tropical marine; mild, tempered by trade winds Ascension Island: tropical marine; mild, semi-arid Tristan da Cunha: temperate marine; mild, tempered by trade winds (tends to be cooler than Saint Helena) |
| Irrigated Land | NA |
| Renewable Water Resources | |
| Environment_CurrentIssues | NA |
| Environment - international agreements | |
| Geography-note | Saint Helena harbors at least 40 species of plants unknown elsewhere in the world; Ascension is a breeding ground for sea turtles and sooty terns; Queen Mary's Peak on Tristan da Cunha is the highest island mountain in the South Atlantic and a prominent landmark on the sea lanes around southern Africa |