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