{ "Introduction": { "Background": { "text": "The Atlantic Ocean is the second largest of the world's five ocean basins (after the Pacific Ocean, but larger than the Indian Ocean, Southern Ocean, and Arctic Ocean). The Kiel Canal (Germany), Oresund (Denmark-Sweden), Bosporus (Turkey), Strait of Gibraltar (Morocco-Spain), and the Saint Lawrence Seaway (Canada-US) are important strategic access waterways. The decision by the International Hydrographic Organization in the spring of 2000 to delimit a fifth world ocean basin, the Southern Ocean, removed the portion of the Atlantic Ocean south of 60 degrees south latitude. For convenience and because of its immense size, the Atlantic Ocean is often divided at the Equator and designated as the North Atlantic Ocean and the South Atlantic Ocean." } }, "Geography": { "Location": { "text": "body of water between Africa, Europe, the Arctic Ocean, the Americas, and the Southern Ocean" }, "Geographic coordinates": { "text": "0 00 N, 25 00 W" }, "Map references": { "text": "Map of the world oceans" }, "Area": { "total ": { "text": "85.133 million sq km" }, "note": "note: includes Baffin Bay, Baltic Sea, Black Sea, Caribbean Sea, Davis Strait, Denmark Strait, part of the Drake Passage, Hudson Bay, Hudson Strait, Gulf of America, Labrador Sea, Mediterranean Sea, North Sea, almost all of the Scotia Sea, and other tributary water bodies" }, "Area - comparative": { "text": "about 7.5 times the size of the US" }, "Coastline": { "text": "111,866 km" }, "Climate": { "text": "tropical cyclones (hurricanes) develop off the coast of Africa near Cabo Verde and move westward into the Caribbean Sea; hurricanes can occur from May to December but are most frequent from August to November" }, "Ocean volume": { "ocean volume": { "text": "310,410,900 cu km" }, "percent of World Ocean total volume": { "text": "23.3%" } }, "Major ocean currents": { "text": "clockwise North Atlantic Gyre consists of the northward flowing, warm Gulf Stream in the west, the eastward flowing North Atlantic Current in the north, the southward flowing cold Canary Current in the east, and the westward flowing North Equatorial Current in the south; the counterclockwise South Atlantic Gyre composed of the southward flowing warm Brazil Current in the west, the eastward flowing South Atlantic Current in the south, the northward flowing cold Benguela Current in the east, and the westward flowing South Equatorial Current in the north" }, "Bathymetry": { "continental shelf": { "text": "The continental shelf (see Figure 1), a rather flat area of the sea floor adjacent to the coast that gradually slopes down from the shore to water depths of about 200 m (660 ft). Dimensions can vary: they may be narrow or nearly nonexistent in some places or extend for hundreds of miles in others. The waters along the continental shelf are usually productive in both plant and animal life, both from sunlight and nutrients from ocean upwelling and terrestrial runoff. The passive margins of the Atlantic Ocean provide for wide continental shelves in North America, Northwest Europe, and the southern coast of South America. The following are examples of features found on the continental shelf of the Atlantic Ocean:

Blake Plateau (Figure 5)
Celtic Shelf (Figure 2)
Dogger Bank (Figure 2)
Flemish Cap (Figure 2)
Falkland Plateau (Figure 3)
Grand Banks of Newfoundland (Figure 2)
Great Bahama Bank (Figure 5)
Little Bahama Bank (Figure 5)
Tunisian Plateau (Figure 4)
Yucatán Shelf (Figure 5)

" }, "continental slope": { "text": "The continental slope (see Figure 1) is where the ocean bottom drops off more rapidly until it meets the deep-sea floor (abyssal plain) at about 3,200 m (10,500 ft) water depth. The deep waters of the continental slope are characterized by cold temperatures, low light conditions, and very high pressures. Sunlight does not penetrate to these depths, having been absorbed or reflected in the water above. The continental slope can be indented by submarine canyons, which are often associated with the outflow of major rivers. Another feature of the continental slope is alluvial fans, or cones of sediments, that major rivers carry downstream to the ocean and deposit down the slope. The following are examples of features found on the continental slope of the Atlantic Ocean:

Amazon Cone (Figure 3)
Congo Fan (Figure 3)
Hudson Canyon (Figure 5)
Mississippi Fan (Figure 5)

" }, "abyssal plains": { "text": "The abyssal plains (see Figure 1), at depths of over 3,000 m (10,000 ft) and covering 70% of the ocean floor, are the largest habitat on earth. Sunlight does not penetrate to the sea floor, making these deep, dark ecosystems less productive than those along the continental shelf. Despite their name, these “plains” are not uniformly flat; they are interrupted by features like hills, valleys, and seamounts. The following are examples of features found on the abyssal plains of the Atlantic Ocean:

Angola Basin (Figure 3)
Agulhas Basin (Figure 3)
Argentine Basin (Figure 3)
Brazil Basin (Figure 3)
Canary Basin (Figure 2)
Cape Basin (Figure 3)
Colombia Basin (Figure 2)
Labrador Basin (Figure 2)
Mexico Basin (Figure 2)
Newfoundland Basin (Figure 2)
North American Basin (Figure 2)
Venezuela Basin (Figure 2)
West European Basin (Figure 2)

" }, "mid-ocean ridge": { "text": "The mid-ocean ridge (see Figure 1), rising from the abyssal plain, is an underwater mountain range, over 64,000 km (40,000 mi) long, reaching an average depth of 2,400 m (8,000 ft). Mid-ocean ridges form at divergent plate boundaries where two tectonic plates are moving apart and magma pushing up from the mantle creates new crust. Tracing their way around the global ocean, this system of underwater volcanoes forms the longest mountain range on Earth. Fracture zones are linear transform faults that develop perpendicular to the line of the mid-ocean ridge, which can offset the ridge line and divide it into segments. The Charlie-Gibbs Fracture Zone displaces the mid-ocean ridge 350 km to the west, separating the Mid-Atlantic Ridge from the Reykjanes Ridge. The Romanche Fracture Zone, located near the Equator, offsets the Mid-Atlantic Ridge 900 km and is considered the dividing line between the North and South Atlantic Oceans. The following are examples of mid-ocean ridges found on the floor of the Atlantic Ocean:

East Mediterranean Ridge (Figure 4)
Mid-Atlantic Ridge (Figures 2, 3)
Reykjanes Ridge (Figure 2)

" }, "undersea terrain features": { "text": "The Abyssal Plain is commonly interrupted by a variety of commonly named undersea terrain features including seamounts, guyots, ridges, and plateaus.

Seamounts (see Figure 1) are submarine mountains at least 1,000 m (3,300 ft) high formed from individual volcanoes on the ocean floor. They are distinct from the plate-boundary volcanic system of the mid-ocean ridges, because seamounts tend to be circular or conical. A circular-collapse caldera is often centered at the summit, evidence of a magma chamber within the volcano. \"Hot spots\" in the deep mantle often feed long chains of seamounts. These hot spots are associated with stationary plumes of molten rock rising from deep within the Earth's mantle. The hot-spot plumes melt through the overlying tectonic plate as it moves and supplies magma to the active volcanic island at the end of the chain of volcanic islands and seamounts. 

Flat topped seamounts are known as guyots.

An undersea ridge is an elongated elevation of varying complexity and size, generally having steep sides.

An undersea plateau is a large, relatively flat elevation that is higher than the surrounding relief with one or more relatively steep sides. Although submerged, these features can reach close to sea level. The following are examples of undersea terrain features found on the floor of the Atlantic Ocean:

Bermuda Rise (Figure 2)
Cape Verde Plateau (Figure 2)
New England Seamounts (Figure 2)
Rio Grande Plateau (Figure 3)
Rockall Plateau (Figure 2)

" }, "ocean trenches": { "text": "Ocean trenches (see Figure 1) are the deepest parts of the ocean floor and are created by the process of subduction. Trenches form along boundaries where tectonic plates are moving toward each other, and one plate sinks (is subducted) under another. The location where the sinking of a plate occurs is called a subduction zone. Subduction can occur when oceanic crust collides with and sinks under (subducts) continental crust, resulting in volcanic, seismic, and mountain-building processes. Subduction can also occur in the convergence of two oceanic plates, where one will sink under the other and in the process create a deep ocean trench.

Subduction processes in oceanic-to-oceanic plate convergence also result in the formation of volcanoes. Over millions of years, the erupted lava and volcanic debris pile up on the ocean floor until a submarine volcano rises above sea level to form a volcanic island. Such volcanoes are typically strung out in curved chains called island arcs. 

The following are examples of ocean trenches found on the floor of the Atlantic Ocean:

Cayman Trench (Caribbean Sea) (Figure 2)
Hellenic Trench (Mediterranean Sea) (Figure 4)
Puerto Rico Trench (Figure 2); note - deepest point in the Atlantic Ocean
South Sandwich Trench (South Atlantic) (Figure 3)

" }, "atolls": { "text": "Atolls are the remains of dormant volcanic islands. In warm tropical oceans, coral colonies establish themselves on the margins of the island. Then, over time, the high elevation of the island collapses and erodes away to sea level, leaving behind an outline of the island in the form of the fringing coral reef. The resulting low island is typified by the coral reef that surrounds a low elevation of sand and coral, with an interior shallow lagoon. Often the remaining dry land is broken into a ring of islets, and some lagoons can be hundreds of square kilometers. 

Guyots are submerged atoll structures, which explains why they are flat-topped.

Rocas Atoll (Brazil) is the only atoll in the South Atlantic." } }, "Elevation": { "highest point": { "text": "sea level" }, "lowest point": { "text": "Puerto Rico Trench -8,605 m" }, "mean depth": { "text": "-3,646 m" }, "ocean zones": { "text": "Composed of water and in a fluid state, the ocean is delimited differently than the solid continents. It is divided into three zones based on depth and light level. Sunlight entering the water may travel about 1,000 m into the ocean under the right conditions, but there is rarely any significant light beyond 200 m.

The upper 200 m (656 ft) of the ocean is called the euphotic, or \"sunlight,\" zone. This zone contains the vast majority of commercial fisheries and is home to many protected marine mammals and sea turtles. Only a small amount of light penetrates beyond this depth.

The zone between 200 m (656 ft) and 1,000 m (3,280 ft) is usually referred to as the \"twilight\" zone, but is officially the dysphotic zone. In this zone, the intensity of light rapidly dissipates as depth increases. Such a minuscule amount of light penetrates beyond a depth of 200 m that photosynthesis is no longer possible.

The aphotic, or \"midnight,\" zone exists in depths below 1,000 m (3,280 ft). Sunlight does not penetrate to these depths, and the zone is bathed in darkness." } }, "Natural resources": { "text": "oil and gas fields, fish, marine mammals (seals and whales), sand and gravel aggregates, placer deposits, polymetallic nodules, precious stones" }, "Natural hazards": { "text": "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": { "text": "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": { "Environment - current issues": { "text": "endangered marine species include the manatee, seals, sea lions, turtles, and whales; unsustainable exploitation of fisheries (over fishing, unregulated bottom trawling, drift net fishing, discards, catch of non-target species); pollution (maritime transport, discharges, offshore drilling, oil spills, plastics from improperly disposed waste); municipal sludge pollution off eastern US, southern Brazil, and eastern Argentina; oil pollution in Caribbean Sea, Gulf of America, Lake Maracaibo, Mediterranean Sea, and North Sea; industrial waste and municipal sewage pollution in Baltic Sea, North Sea, and Mediterranean Sea" }, "Climate": { "text": "tropical cyclones (hurricanes) develop off the coast of Africa near Cabo Verde and move westward into the Caribbean Sea; hurricanes can occur from May to December but are most frequent from August to November" }, "Marine fisheries": { "text": "

the Atlantic Ocean fisheries are the second most important in the world accounting for 25.8%, or 20,300,000 mt, of the global catch in 2020; of the seven regions delineated by the Food and Agriculture Organization in the Atlantic basin, the most important include the following:

Northeast Atlantic region (Region 27) is the fourth most important in the world, producing 10.5% of the global catch or 8,310,000 mt in 2020; the region encompasses the waters north of 36º North latitude and east of 40º West longitude, with the major producers including Norway (3,528,240 mt), Russia (1,044,153 mt), Iceland (933,019 mt), UK (823,669 mt), and Denmark (641,927 mt); the region includes the historically important fishing grounds of the North Sea, the Baltic Sea, and the Atlantic waters around Greenland, Iceland, and the British Isles; the principal catches include Atlantic cod, haddock, saithe (pollock), blue whiting, herring, and mackerel

Eastern Central Atlantic region (Region 34) is the second most important Atlantic fishery, and seventh largest in the world, producing more than 6.3% of the global catch or 4,950,000 mt in 2020; the region encompasses the waters between 36º North and 6º South latitude and east of 40º West longitude off the west coast of Africa, with the major producers including Morocco (1,419,872 mt), Mauritania (705,850 mt), Senegal (472,571 mt), Nigeria (451,768 mt), Ghana (303,001 mt), Cameroon (265,969 mt), and Sierra Leone (200,000 mt); the principal catches include pilchard, sardinellas, shad, and mackerel

Northwest Atlantic region (Region 21) is the fourth most important Atlantic fishery and eleventh in the world producing 1.9% of the global catch and 1,540,000 mt in 2020; it encompasses the waters north of 35º North latitude and west of 42º West longitude, including major fishing grounds over North America's continental shelf (the Grand Banks, Georges Bank, Flemish Cap, and Baffin Bay); the major producers include the US (927,777 mt), Canada (615,651 mt), and Greenland (179,990 mt); the principal catches include sea scallops, prawns, lobster, herring, and menhaden

Mediterranean and Black Sea region (Region 37) is a minor fishing region representing 1.5% or 1,190,000 mt of the world’s total capture in 2020; the region encompasses all waters east of the Strait of Gibraltar, with the major producers including Turkey (686,650 mt), Italy (281,212 mt), Tunisia (129,325 mt), Spain (119,759 mt), and Russia (72,279 mt); the principal catches include European anchovy, European pilchard, gobies, and clams

Regional fisheries bodies: Commission for the Conservation of Southern Bluefin Tuna, Fishery Committee for the Eastern Central Atlantic, Fisheries Committee for the West Central Gulf of Guinea, General Fisheries Commission for the Mediterranean, International Commission for the Conservation of Atlantic Tunas, International  Council for the Exploration of the Seas, Northwest Atlantic Fisheries Organization, North Atlantic Salmon Conservation Organization, North East Atlantic Fisheries Commission, Southeast Atlantic Fisheries Organization, Western Central Atlantic Fishery Commission

" } }, "Government": { "Country name": { "etymology": { "text": "name derives from the Greek description of the waters beyond the Strait of Gibraltar, Atlantis thalassa, meaning \"Sea of Atlas\"" } } }, "Economy": { }, "Transportation": { "Transportation - note": { "text": "Kiel Canal and Saint Lawrence Seaway are two important waterways; significant domestic commercial and recreational use of Intracoastal Waterway on central and south Atlantic seaboard and Gulf of America coast of US" } }, "Military and Security": { }, "Transnational Issues": { } }