Visualiser les conditions éoliennes, météorologiques, océanographiques et de pollution actuelles, telles que prévues par des superordinateurs, sur une carte animée interactive. [43] The origin of the Sargasso fauna and flora remained enigmatic for centuries. Large variations in the subpolar gyre on a decade-century scale, associated with the North Atlantic oscillation, are especially pronounced in Labrador Sea Water, the upper layers of the MOC. For instance, on the North American side of the ocean, large carbonate deposits formed in warm shallow waters such as Florida and the Bahamas, while coarse river outwash sands and silt are common in shallow shelf areas like the Georges Bank. Likewise, GDP doubled in Atlantic countries but rose by only 30% in the rest of Europe. Saison cyclonique dans l'océan Atlantique sud‎ – 1 C Pages dans la catégorie « Climat de l'océan Atlantique » Cette catégorie contient les 6 pages suivantes. England, France, and the Dutch Republic enviously watched the Spanish and Portuguese wealth grow and allied themselves with pirates such as Henry Mainwaring and Alexandre Exquemelin. The biggest culprits are rivers and with them many agriculture fertilizer chemicals as well as livestock and human waste. [52] Météo des plages de l'océan Atlantique La façade Atlantique dispose en majorité de grandes plages de sable fin, souvent bien animées tout au long de l'année. The cold water currents contribute to heavy fog off the coast of eastern Canada (the Grand Banks of Newfoundland area) and Africa's north-western coast. Dans l'Océan Atlantique Nord le courant chaud de surface est nommée " Gulf Stream " en anglais, ou "Courant du Golfe" en français, il prend sa source en Floride et se dilue lentement jusqu'au Groenland. Municipal pollution comes from the eastern United States, southern Brazil, and eastern Argentina; oil pollution in the Caribbean Sea, Gulf of Mexico, Lake Maracaibo, Mediterranean Sea, and North Sea; and industrial waste and municipal sewage pollution in the Baltic Sea, North Sea, and Mediterranean Sea. In 1500, in his voyage to India following Vasco da Gama, Pedro Alvares Cabral reached Brazil, taken by the currents of the South Atlantic Gyre. [63], An embryonic subduction margin is potentially developing west of Gibraltar. The temperatures given are the sea surface temperature (SST) which is most relevant to recreational users. Iceland was initially settled 865–930 CE following a warm period when winter temperatures hovered around 2 °C (36 °F) which made farming favorable at high latitudes. [80] Six years later Vasco da Gama reached India under the Portuguese flag, by navigating south around the Cape of Good Hope, thus proving that the Atlantic and Indian Oceans are connected. [6], In the North Atlantic, surface circulation is dominated by three inter-connected currents: the Gulf Stream which flows north-east from the North American coast at Cape Hatteras; the North Atlantic Current, a branch of the Gulf Stream which flows northward from the Grand Banks; and the Subpolar Front, an extension of the North Atlantic Current, a wide, vaguely defined region separating the subtropical gyre from the subpolar gyre. Fisheries have, however, undergone significant changes since the 1950s and global catches can now be divided into three groups of which only two are observed in the Atlantic: fisheries in the Eastern Central and South-West Atlantic oscillate around a globally stable value, the rest of the Atlantic is in overall decline following historical peaks. [92] The North Atlantic garbage patch is estimated to be hundreds of kilometers across in size.[90]. Spain and Portugal monopolized this trade in order to keep other European nations out, but conflicting interests nevertheless led to a series of Spanish-Portuguese wars. Il sépare l'Eurafrique de l'Amérique et du Groenland, et il est né de cassures d'âge secondaire, qui n'ont cessé de s'élargir depuis. [88], Marine pollution is a generic term for the entry into the ocean of potentially hazardous chemicals or particles. These include the Baltic Sea, Black Sea, Caribbean Sea, Davis Strait, Denmark Strait, part of the Drake Passage, Gulf of Mexico, Labrador Sea, Mediterranean Sea, North Sea, Norwegian Sea, almost all of the Scotia Sea, and other tributary water bodies. Iceland began to form 62 million years ago due to a particularly concentrated mantle plume. No later than 130 Ma rifting had reached the Walvis Ridge–Rio Grande Rise. [26] The depth of water at the apex of the ridge is less than 2,700 m (1,500 fathoms; 8,900 ft) in most places, while the bottom of the ridge is three times as deep. Une équipe de chercheurs a récemment fourni la réponse grâce à l’analyse détaillée de sédiments lacustres. The most important species in the area, Gulf menhaden, reached a million tons in the mid-1980s but only half a million tons in 2013 and is now considered fully fished. [31] The exploration of the MAR in the 1950s led to the general acceptance of seafloor spreading and plate tectonics. Traces of magmatism in both offshore and onshore basins in the central and southern segments have been dated to 147–49 Ma with two peaks between 143 and 121 Ma and 90–60 Ma. [61], The equatorial segment is the last phase of the break-up, but, because it is located on the Equator, magnetic anomalies cannot be used for dating. [91], North Atlantic hurricane activity has increased over past decades because of increased sea surface temperature (SST) at tropical latitudes, changes that can be attributed to either the natural Atlantic Multidecadal Oscillation (AMO) or to anthropogenic climate change. Minimum : 33°F/Maximum : 84°F Température de l'eau de l'océan atlantique en février Avec une température largement sous les moyennes dans l'océan Pacifique equatorial, nous assistons depuis plusieurs mois à un phénomène dit "La Niña". The Atlantic Subarctic Upper Water in the northernmost North Atlantic is the source for Subarctic Intermediate Water and North Atlantic Intermediate Water. 21st-century global warming will probably result in an equilibrium sea-level rise five times greater than today, whilst melting of glaciers, including that of the Greenland ice-sheet, expected to have virtually no effect during the 21st century, will probably result in a sea-level rise of 3–6 m over a millennium. This involved little guesswork because the idea of sonar is straight forward with pulses being sent from the vessel, which bounce off the ocean floor, then return to the vessel. [61], In the central segment rifting started to break Africa in two by opening the Benue Trough around 118 Ma. Large quantities of basalt erupted at this time period are found on Baffin Island, Greenland, the Faroe Islands, and Scotland, with ash falls in Western Europe acting as a stratigraphic marker. [9] In these uses, the name refers to Atlas, the Titan in Greek mythology, who supported the heavens and who later appeared as a frontispiece in Medieval maps and also lent his name to modern atlases. Groupers and snappers are overfished and northern brown shrimp and American cupped oyster are considered fully fished approaching overfished. [43], Other species endemic to the Sargasso Sea include the sargassum fish, a predator with algae-like appendages which hovers motionless among the Sargassum. [6], The Atlantic harbors petroleum and gas fields, fish, marine mammals (seals and whales), sand and gravel aggregates, placer deposits, polymetallic nodules, and precious stones. The 20° East meridian, running south from Cape Agulhas to Antarctica defines its border. A settlement on Greenland was established before 1000 CE, but contact with it was lost in 1409 and it was finally abandoned during the early Little Ice Age. The extent of the volcanism has been estimated to 4.5×106 km2 (1.7×106 sq mi) of which 2.5×106 km2 (9.7×105 sq mi) covered what is now northern and central Brazil. [84] The coldest zones are in high latitudes, with the coldest regions corresponding to the areas covered by sea ice. [6], The Coriolis effect circulates North Atlantic water in a clockwise direction, whereas South Atlantic water circulates counter-clockwise. ", "The great American schism: divergence of marine organisms after the rise of the Central American Isthmus", "On the Movements of the North Atlantic Subpolar Front in the Preinstrumental Past", "Coastal South Africa and the Coevolution of the Modern Human Lineage and the Coastal Adaptation", "Stone age people in a changing South African greater Cape Floristic Region", "Stability of the thermohaline circulation under millennial CO2 forcing and two alternative controls on Atlantic salinity", "The Discovery of America: The first Americans may have swept the Western Hemisphere and decimated its fauna within 1000 years", "Extensive 200-million-year-old continental flood basalts of the Central Atlantic Magmatic Province", "Why did modern human populations disperse from Africa ca. In the western Atlantic carbonate platforms dominate large areas, for example, the Blake Plateau and Bermuda Rise. The sea snail perlemoen abalone is targeted by illegal fishing and remain overfished. Selon une étude publiée par l'Université de Londres, une augmentation de la température à la surface de l'océan de l'ordre de 0,5°C a élevé de 40% le nombre d'ouragans dans l'océan Atlantique entre 1996 et 2005. The population of a number of deep-sea fishes also collapsed in the process, including American plaice, redfish, and Greenland halibut, together with flounder and grenadier. [92] Therefore, these changes in SST must be caused by human activities. A peace treaty mediated by the Pope divided the conquered territories into Spanish and Portuguese sectors while keeping other colonial powers away. [62], In the Falkland segment rifting began with dextral movements between the Patagonia and Colorado sub-plates between the Early Jurassic (190 Ma) and the Early Cretaceous (126.7 Ma). Half the stocks in this area are being fished at unsustainable levels: Whitehead's round herring has not yet reached fully fished but Cunene horse mackerel is overfished. [41] [78] [6] In contrast, 8–7 kya-old shell middens in Portugal, Denmark, and Brazil generated thousands of tons of debris and artefacts. [54], Geologically, the Northern Atlantic is the area delimited to the south by two conjugate margins, Newfoundland and Iberia, and to the north by the Arctic Eurasian Basin. A. R. 1. Prévisions des conditions de baignade : température de l'eau, indice UV et état de la mer. La température de l'océan Atlantique, sur les côtes canadiennes, continue de grimper, selon la plus récente étude sur les conditions océanographiques de Pêches et Océans Canada. The Atlantic Ocean is bounded on the west by North and South America. A new model", "History of NOAA Ocean Exploration: Timeline", "The human genetic history of the Americas: the final frontier", "Two millennia of North Atlantic seasonality and implications for Norse colonies", "Global continental and ocean basin reconstructions since 200Ma", "Tracing the flow of North Atlantic Deep Water using chlorofluorocarbons", "On the water masses and mean circulation of the South Atlantic Ocean", "A new scheme for the opening of the South Atlantic Ocean and the dissection of an Aptian salt basin", "The North Atlantic subpolar gyre in four high-resolution models", "Mapping of the Puerto Rico Trench, the Deepest Part of the Atlantic, is Nearing Completion", "The Red Atlantic: American Indigenes and the Making of the Modern World, 1000–1927", "Changes in tropical cyclone number, duration, and intensity in a warming environment", "Map of Atlantic Coast of North America from the Chesapeake Bay to Florida", https://en.wikipedia.org/w/index.php?title=Atlantic_Ocean&oldid=994576088, Short description is different from Wikidata, Wikipedia introduction cleanup from December 2020, Articles covered by WikiProject Wikify from December 2020, All articles covered by WikiProject Wikify, All Wikipedia articles written in American English, Articles using infobox body of water without pushpin map, Articles using infobox body of water without image bathymetry, Articles containing Ancient Greek (to 1453)-language text, Articles to be expanded from December 2020, Articles with dead external links from June 2019, Articles with permanently dead external links, Articles with dead external links from May 2019, Articles with dead external links from July 2017, Wikipedia articles with WORLDCATID identifiers, Creative Commons Attribution-ShareAlike License, 111,866 km (69,510 mi) including marginal seas, This page was last edited on 16 December 2020, at 12:50. L'étude s'est concentrée sur 11 modèles informatiques qui reproduisaient le plus fidèlement les différentes strates de température de l'océan Atlantique nord. [30], The remainder of the ridge was discovered in the 1920s by the German Meteor expedition using echo-sounding equipment. Colonialism evolved as part of the Trans-Atlantic trade, but this trade also strengthened the position of merchant groups at the expense of monarchs. During the 21st century some species have shown weak signs of recovery, including Greenland halibut, yellowtail flounder, Atlantic halibut, haddock, spiny dogfish, while other stocks shown no such signs, including cod, witch flounder, and redfish. [86], In the South-East Atlantic catches have decreased from 3.3 million tons in the early 1970s to 1.3 million tons in 2013. Stocks of invertebrates, in contrast, remain at record levels of abundance. The South Atlantic Central Water originates in this gyre, while Antarctic Intermediate Water originates in the upper layers of the circumpolar region, near the Drake Passage and the Falkland Islands. The GCFR is delimited to the north by the Cape Fold Belt and the limited space south of it resulted in the development of social networks out of which complex Stone Age technologies emerged. [85], Various international treaties attempt to reduce pollution caused by environmental threats such as oil spills, marine debris, and the incineration of toxic wastes at sea. 50 kya-old, deeply stratified shell middens found in Ysterfontein on the western coast of South Africa are associated with the Middle Stone Age (MSA). Mises à … This system of currents transport warm water into the North Atlantic, without which temperatures in the North Atlantic and Europe would plunge dramatically. The Atlantic Ocean is divided into two parts, by the Equatorial Counter Current, with the North(ern) Atlantic Ocean and the South(ern) Atlantic Ocean at about 8°N. The Gulf Stream also keeps extreme temperatures from occurring on the Florida Peninsula. [44], The location of the spawning ground for European eels remained unknown for decades. The south tides in the Atlantic Ocean are semi-diurnal; that is, two high tides occur during every 24 lunar hours. The International Hydrographic Organization (IHO) defined the limits of the oceans and seas in 1953,[17] but some of these definitions have been revised since then and some are not used by various authorities, institutions, and countries, see for example the CIA World Factbook. [74] These hypotheses remained the long-held view regarding the settlement of the Americas, a view challenged by more recent archaeological discoveries: the oldest archaeological sites in the Americas have been found in South America; sites in north-east Siberia report virtually no human presence there during the LGM; and most Clovis artefacts have been found in eastern North America along the Atlantic coast. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea and Barents Sea. Following rapid climate changes at the end of the LGM this region was repopulated by Magdalenian culture. Furthermore, it is clear from statistical analyses of annual tropical cyclones that these changes do not display multidecadal cyclicity. The reduced quantities of shells in the lower levels can represent the few shells that were exported inland.[72]. This setback was caused by a range of factors: an unsustainable economy resulted in erosion and denudation, while conflicts with the local Inuit resulted in the failure to adapt their Arctic technologies; a colder climate resulted in starvation, and the colony got economically marginalized as the Great Plague and Barbary pirates harvested its victims on Iceland in the 15th century. L'eau se refroidit, se mélange à de l'eau froide venant de l'océan arctique, et devient si dense qu'elle descend, au sud et à l'est du Groenland. 60,000 years ago? In the North-East Atlantic 21% of stocks are considered overfished. The NADW, in its turn, feeds the meridional overturning circulation (MOC), the northward heat transport of which is threatened by anthropogenic climate change. [86], In the South-West Atlantic, a peak was reached in the mid-1980s and catches now fluctuate between 1.7 and 2.6 million tons. [87], In the Eastern Central Atlantic small pelagic fishes constitute about 50% of landings with sardine reaching 0.6–1.0 million tons per year. In the early 1990s, this finally resulted in the collapse of the Atlantic northwest cod fishery. While their middens resemble 12–11 kya-old Late Stone Age (LSA) middens found on every inhabited continent, the 50–45 kya-old Enkapune Ya Muto in Kenya probably represents the oldest traces of the first modern humans to disperse out of Africa. [24], The MAR divides the Atlantic longitudinally into two-halves, in each of which a series of basins are delimited by secondary, transverse ridges. Active and inactive spreading systems in this area are marked by the interaction with the Iceland hotspot. [28] A much vaguer, nameless boundary, between the North American and South American plates, intersects the MAR near or just north of the Fifteen-Twenty Fracture Zone, approximately at 16°N.[29]. Rifting in the central segment, however, coincided with the Cretaceous Normal Superchron (also known as the Cretaceous quiet period), a 40 Ma period without magnetic reversals, which makes it difficult to date sea-floor spreading in this segment. [27], The MAR is intersected by two perpendicular ridges: the Azores–Gibraltar Transform Fault, the boundary between the Nubian and Eurasian plates, intersects the MAR at the Azores Triple Junction, on either side of the Azores microplate, near the 40°N. [10] The Greek word thalassa has been reused by scientists for the huge Panthalassa ocean that surrounded the supercontinent Pangaea hundreds of millions of years ago. [83], Trans-Atlantic trade also resulted in increasing urbanization: in European countries facing the Atlantic, urbanization grew from 8% in 1300, 10.1% in 1500, to 24.5% in 1850; in other European countries from 10% in 1300, 11.4% in 1500, to 17% in 1850. [4] The average depth is 3,646 m (11,962 ft) and the maximum depth, the Milwaukee Deep in the Puerto Rico Trench, is 8,376 m (27,480 ft). The North Atlantic covers 41,490,000 km2 (16,020,000 sq mi) (11.5%) and the South Atlantic 40,270,000 km2 (15,550,000 sq mi) (11.1%). Changes in the formation of NADW have been linked to global climate changes in the past. Meteo Paris - … Currently, there is no cost-effective way to mine or extract gold from the ocean to make a profit. "[73] Others later proposed a "three-wave" migration over the Bering Land Bridge. [24], Continental shelves in the Atlantic are wide off Newfoundland, southernmost South America, and north-eastern Europe. 211):[7] Atlantikôi pelágei (Greek: Ἀτλαντικῷ πελάγει; English: 'the Atlantic sea'; etym. For their own safety, the crew jettisoned two nuclear bombs, which were never recovered. The exact timing is controversial with estimates ranging from 200 to 170 Ma. Drift net fishing can kill dolphins, albatrosses and other seabirds (petrels, auks), hastening the fish stock decline and contributing to international disputes. Maximum temperatures occur north of the equator, and minimum values are found in the polar regions. Besides major transatlantic transportation and communication routes, the Atlantic offers abundant petroleum deposits in the sedimentary rocks of the continental shelves. [40], The South Atlantic is dominated by the anti-cyclonic southern subtropical gyre. La figure 4.3 représente la distribution moyenne de la température sur une coupe de l'océan Atlantique Ouest.Cette figure illustre bien le confinement des températures élevées dans la partie supérieure de l'océan. In the early 19th century it was discovered that the southern Sargasso Sea is the spawning ground for both the European and American eel and that the former migrate more than 5,000 km (3,100 mi) and the latter 2,000 km (1,200 mi). Ceci pourrait notamment expliquer la forte activité cyclonique dans l'Ouest du Pacifique et surtout sur l'Atlantique. [38], North of the North Atlantic Gyre, the cyclonic North Atlantic Subpolar Gyre plays a key role in climate variability. Geologists distinguish two magmatic phases. There are numerous submarine canyons off north-eastern North America, western Europe, and north-western Africa. [51], The opening of the Atlantic Ocean coincided with the initial break-up of the supercontinent Pangaea, both of which were initiated by the eruption of the Central Atlantic Magmatic Province (CAMP), one of the most extensive and voluminous large igneous provinces in Earth's history associated with the Triassic–Jurassic extinction event, one of Earth's major extinction events. Ocean currents such as the Gulf Stream transport eel larvae from the Sargasso Sea to foraging areas in North America, Europe, and Northern Africa. Off South Africa and Namibia deep-water hake and shallow-water Cape hake have recovered to sustainable levels since regulations were introduced in 2006 and the states of Southern African pilchard and anchovy have improved to fully fished in 2013. The most productive areas include the Grand Banks of Newfoundland, the Scotian Shelf, Georges Bank off Cape Cod, the Bahama Banks, the waters around Iceland, the Irish Sea, the Bay of Fundy, the Dogger Bank of the North Sea, and the Falkland Banks. For example, the Gulf Stream helps moderate winter temperatures along the coastline of southeastern North America, keeping it warmer in winter along the coast than inland areas. The third group, "continuously increasing trend since 1950", is only found in the Indian Ocean and Western Pacific. The second-largest ocean on Earth, the Atlantic drives our weather patterns, including hurricanes, and is home to many species from sea turtles to dolphins. Atlantic Ocean, body of salt water covering about one-fifth of Earth’s surface and separating the continents of Europe and Africa to the east from those of North and South America to the west. For European countries with direct access to the Atlantic (including Britain, France, the Netherlands, Portugal, and Spain) 1500–1800 was a period of sustained growth during which these countries grew richer than those in Eastern Europe and Asia. The warmest Pornichet sea water temperatures in the middle of August require something like a … [76] A proposed route across the Pacific to South America could explain early South American finds and another hypothesis proposes a northern path, through the Canadian Arctic and down the North American Atlantic coast. [25], The MAR rises 2–3 km (1.2–1.9 mi) above the surrounding ocean floor and its rift valley is the divergent boundary between the North American and Eurasian plates in the North Atlantic and the South American and African plates in the South Atlantic. Recovery plans for cod, sole, and plaice have reduced mortality in these species. [77] The Ertebølle middens in Denmark, for example, accumulated 2,000 m3 (71,000 cu ft) of shell deposits representing some 50 million molluscs over only a thousand years. The opening of the Northern Atlantic closely followed the margins of its predecessor, the Iapetus Ocean, and spread from the Central Atlantic in six stages: Iberia–Newfoundland, Porcupine–North America, Eurasia–Greenland, Eurasia–North America. 44% of stocks are being fished at unsustainable levels. The Atlantic is surrounded by passive margins except at a few locations where active margins form deep trenches: the Puerto Rico Trench (8,376 m or 27,480 ft maximum depth) in the western Atlantic and South Sandwich Trench (8,264 m or 27,113 ft) in the South Atlantic. The formation of the isthmus resulted in the migration and extinction of many land-living animals, known as the Great American Interchange, but the closure of the seaway resulted in a "Great American Schism" as it affected ocean currents, salinity, and temperatures in both the Atlantic and Pacific. Precipitation can be approximated from coastal weather data and air temperature from water temperatures. December average water temperature in Atlantic City is 9.1°C/48.4°F, the minimum temperature is 4.4°C/39.9°F, and the maximum is 13.6°C/56.5°F. Theoliitic dikes, sills, and lava flows from the CAMP eruption at 200 Ma have been found in West Africa, eastern North America, and northern South America. The term "Aethiopian Ocean", derived from Ancient Ethiopia, was applied to the Southern Atlantic as late as the mid-19th century. It is known to separate the "Old World" from the "New World" in European perception of the World. [6], From October to June the surface is usually covered with sea ice in the Labrador Sea, Denmark Strait, and Baltic Sea. On the African east coast the small cyclonic Angola Gyre lies embedded in the large subtropical gyre.

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