Background: A spring 2000 decision by the International Hydrographic Organization delimited a fifth world ocean from the southern portions of the Atlantic Ocean Indian Ocean and Pacific Ocean. The new ocean extends from the coast of Antarctica north to 60 degrees south latitude which coincides with the Antarctic Treaty Limit. The Atlantic Ocean remains the second-largest of the world's five oceans (after the Pacific Ocean but larger than the Indian Ocean Southern Ocean and Arctic Ocean).
Climate: tropical cyclones (hurricanes) develop off the coast of Africa near Cape Verde and move westward into the Caribbean Sea; hurricanes can occur from May to December but are most frequent from August to November
Terrain: surface usually covered with sea ice in Labrador Sea Denmark Strait and Baltic Sea from October to June; clockwise warm-water gyre (broad circular system of currents) in the northern Atlantic counterclockwise warm-water gyre in the southern Atlantic; the ocean floor is dominated by the Mid-Atlantic Ridge a rugged north-south centerline for the entire Atlantic basin
Natural resources: oil and gas fields fish marine mammals (seals and whales) sand and gravel aggregates placer deposits polymetallic nodules precious stones
Natural hazards: icebergs common in Davis Strait Denmark Strait and the northwestern Atlantic Ocean from February to August and have been spotted as far south as Bermuda and the Madeira Islands; ships subject to superstructure icing in extreme northern Atlantic from October to May; persistent fog can be a maritime hazard from May to September; hurricanes (May to December)
Geography Note: major chokepoints include the Dardanelles Strait of Gibraltar access to the Panama and Suez Canals; strategic straits include the Strait of Dover Straits of Florida Mona Passage The Sound (Oresund) and Windward Passage; the Equator divides the Atlantic Ocean into the North Atlantic Ocean and South Atlantic Ocean
Environment Current issues: endangered marine species include the manatee seals sea lions turtles and whales; drift net fishing is hastening the decline of fish stocks and contributing to international disputes; municipal sludge pollution off eastern US southern Brazil and eastern Argentina; oil pollution in Caribbean Sea Gulf of Mexico Lake Maracaibo Mediterranean Sea and North Sea; industrial waste and municipal sewage pollution in Baltic Sea North Sea and Mediterranean Sea
Economy overview: The Atlantic Ocean provides some of the world's most heavily trafficked sea routes between and within the Eastern and Western Hemispheres. Other economic activity includes the exploitation of natural resources e.g. fishing the dredging of aragonite sands (The Bahamas) and production of crude oil and natural gas (Caribbean Sea Gulf of Mexico and North Sea).