Saint Helena Geography Profile 2009

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

Map references

Africa

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

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