Geography of the Atlantic Ocean

Geography of the Atlantic Ocean
Name	Atlantic Ocean
Caption	Bathymetric map of the Atlantic Ocean basin
Area	85,133,000 km2
Depth	3,646 m (mean)
Max-depth	8,486 m (Puerto Rico Trench)
Countries	United States, Canada, Brazil, United Kingdom, Ireland, Iceland, Norway, Spain, Portugal, France, Morocco, Senegal, Nigeria, Gabon, South Africa, Argentina, Uruguay, Uruguay, Dominican Republic, Cuba, Haiti, Jamaica, Bahamas, Chile

Geography of the Atlantic Ocean The Atlantic Ocean is the second-largest oceanic division, bounded by the Americas, Europe, and Africa and linked to the Arctic Ocean and Southern Ocean. Its basin has shaped exploration, trade, and geopolitics from the Age of Discovery through the Atlantic Charter era to contemporary agreements like the United Nations Convention on the Law of the Sea. Major ports such as New York City, Lisbon, Hamburg, Buenos Aires, and Cape Town attest to its central role in global connectivity.

Overview and Extent

The basin spans from the Greenland Sea and the Barents Sea margins in the north to the Southern Ocean convergence near Antarctica in the south and includes marginal seas like the Caribbean Sea, Gulf of Mexico, Mediterranean Sea, Baltic Sea, and North Sea. It is segmented into the North Atlantic Ocean and the South Atlantic Ocean by the Equator, with subregions such as the Sargasso Sea, Labrador Sea, Irminger Sea, and Scotia Sea. Continental shelves off Brazil, West Africa, and the North American Atlantic coast influence shelf sea processes observed near the Grand Banks, Patagonia, and the Iberian Peninsula.

Oceanographic Structure and Circulation

The Atlantic’s circulation is dominated by the Atlantic Meridional Overturning Circulation (AMOC), which includes the Gulf Stream, North Atlantic Drift, Canary Current, and the Brazil Current, connecting subtropical gyres, the Subtropical Convergence, and polar sinks. Thermohaline gradients driven by salinity and temperature interact with wind-forced features like the North Atlantic Oscillation and the El Niño–Southern Oscillation teleconnections affecting the Caribbean, Azores, and Scandinavian margins. Water masses such as North Atlantic Deep Water, Antarctic Intermediate Water, and Mediterranean Outflow Water define vertical stratification, while mesoscale eddies and fronts appear along the Cape Verde and Falkland shelves.

Geology and Seafloor Features

The mid-ocean ridge system through the Atlantic is anchored by the Mid-Atlantic Ridge, which forms plate boundaries between the North American Plate, Eurasian Plate, South American Plate, and African Plate. Transform faults, fracture zones, abyssal plains, and features such as the Romanche Trench, Puerto Rico Trench, Charleston Bump, and Bermuda Rise record tectonic spreading and mantle dynamics. Continental margins include passive margins like the East Coast of the United States and West Africa, and active features influenced by hotspots near Iceland and seamount chains adjacent to Azores and Canary Islands volcanic provinces.

Climate and Weather Patterns

Atmospheric interactions produce prominent storm tracks including the North Atlantic storm track linked to the Jet Stream and the Azores High, which influence rainfall over Iberia, Morocco, and the Mediterranean Basin. Tropical cyclones forming in the Cape Verde region travel across the Caribbean Sea and Gulf of Mexico to affect Florida, Cuba, and Mexico. Climate variability tied to the Atlantic Multidecadal Oscillation and anthropogenic forcing observed in assessments by the Intergovernmental Panel on Climate Change alter sea surface temperatures, sea level rise documented by NOAA, and marine heatwaves impacting regions from the Bay of Biscay to the Patagonian Shelf.

Coastal Regions and Islands

The Atlantic rim comprises diverse coasts from the fjords of Norway and Greenland to the deltas of the Niger River and Amazon River, and sandy shores like the Outer Banks and the Cape Verde archipelago. Island groups include the Caribbean islands with Hispaniola, Cuba, Jamaica, the Antilles, North Atlantic archipelagos like the Azores, Madeira, Canary Islands, and volcanic islands such as Bermuda and Sao Tome and Principe. Important estuarine systems include the Chesapeake Bay, Gulf of St. Lawrence, and the Rio de la Plata which host critical fisheries and urban centers like Lisbon, Liverpool, Boston, and Montevideo.

Biodiversity and Marine Ecosystems

The Atlantic supports ecosystems from polar systems in the Barents Sea and Labrador Sea to tropical coral reefs in the Mesoamerican Barrier Reef and Florida Reef Tract. Productive upwelling zones off Peru and Mauritania drive fisheries targeting Atlantic cod, herring, sardine, and anchoveta stocks managed under regimes like the Northwest Atlantic Fisheries Organization and the International Commission for the Conservation of Atlantic Tunas. Marine megafauna include North Atlantic right whale populations, green sea turtle migrations, and pelagic species such as Atlantic bluefin tuna and makos; benthic habitats host cold-water corals documented near Porcupine Bank and seamount assemblages adjacent to Rockall.

Human Use and Economic Geography

Human activity encompasses shipping lanes like the North Atlantic Sea Lane and the Panama canal connections to Pacific Ocean trade, offshore hydrocarbon fields on the Grand Banks and Gulf of Mexico, and mineral interest in manganese nodules on abyssal plains. Fisheries, transatlantic telecommunication cables linking Newfoundland and Portugal, tourism in the Caribbean and Azores, and naval passages used historically in conflicts including the Battle of the Atlantic reflect strategic importance. Governance frameworks include International Maritime Organization conventions and continental arrangements among European Union states, African Union members, and CARICOM countries managing resources, environmental protection, and response to hazards like oil spills exemplified by incidents near Prestige and Deepwater Horizon.

Category:Atlantic Ocean