Geography of Saint Helena
| 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 2300 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 |
| Map references: | Africa |
| Area: | total: 413 sq km land: Saint Helena Island 122 sq km; Ascension Island 90 sq km; Tristan da Cunha island group 201 sq km water: 0 sq km |
| Area - comparative: | slightly more than twice the size of Washington, DC |
| Land boundaries: | 0 km |
| Coastline: | Saint Helena: 60 km Ascension Island: NA Tristan da Cunha: 40 km |
| Maritime claims: | territorial sea: 12 nm exclusive fishing zone: 200 nm |
| 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) |
| 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 |
| Elevation extremes: | lowest point: Atlantic Ocean 0 m highest point: Queen Mary's Peak on Tristan da Cunha 2,062 m; Green Mountain on Ascension Island 859 m; Mount Actaeon on Saint Helena Island 818 m |
| Natural resources: | fish, lobster |
| Land use: | arable land: 12.9% permanent crops: 0% other: 87.1% (2005) |
| Irrigated land: | NA |
| Natural hazards: | active volcanism on Tristan da Cunha, last eruption in 1961 |
| Environment - current issues: | NA |
| Geography - note: | Saint Helena harbors at least 40 species of plants unknown anywhere else 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 |