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84-796: Second Fleet's area of responsibility includes about 6,700,000 square miles (17,000,000 km) of the Atlantic Ocean from the North Pole to the Caribbean and from the shores of the United States to the middle of the Atlantic Ocean . Second Fleet's United States West Coast counterpart was United States First Fleet from the immediate post-World War II years until 1973, and United States Third Fleet from 1973. In 2011, Second Fleet oversaw about 126 ships, 4,500 aircraft, and 90,000 personnel homeported at U.S. Navy installations along

168-492: A World Heritage Site for their geological value, four of them are considered of "Outstanding Universal Value" based on their cultural and natural criteria: Þingvellir , Iceland; Landscape of the Pico Island Vineyard Culture , Portugal; Gough and Inaccessible Islands , United Kingdom; and Brazilian Atlantic Islands: Fernando de Noronha and Atol das Rocas Reserves, Brazil. Continental shelves in

252-505: A DoD news article that the Navy would disestablish Second Fleet in order to "use those savings and more to fund additional ships". The fleet was officially dissolved in a ceremony at Norfolk on 30 September 2011. Second Fleet's responsibilities and its additional title of Commander, Task Force 20 , were transferred to the re-organized United States Fleet Forces Command , as was the post of CJOS COE. On 4 May 2018, Admiral Chris Grady announced

336-506: A Navy Sonic Depth Finder to draw a continuous map across the bed of the Atlantic. This involved little guesswork because the idea of sonar is straightforward with pulses being sent from the vessel, which bounce off the ocean floor, then return to the vessel. The deep ocean floor is thought to be fairly flat with occasional deeps, abyssal plains , trenches , seamounts , basins , plateaus , canyons , and some guyots . Various shelves along

420-721: 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. This system of currents transports warm water into the North Atlantic, without which temperatures in the North Atlantic and Europe would plunge dramatically. North of

504-416: A weak Intertropical Convergence Zone , South Atlantic tropical cyclones are rare. The Atlantic Ocean is underlain mostly by dense mafic oceanic crust made up of basalt and gabbro and overlain by fine clay, silt and siliceous ooze on the abyssal plain. The continental margins and continental shelf mark lower density, but greater thickness felsic continental rock that is often much older than that of

588-621: Is a complex of four water masses, two that form by deep convection in the open ocean – classical and upper Labrador sea water – and two that form from the inflow of dense water across the Greenland-Iceland-Scotland sill – Denmark Strait and Iceland-Scotland overflow water. Along its path across Earth the composition of the NADW is affected by other water masses, especially Antarctic bottom water and Mediterranean overflow water. The NADW

672-467: Is fed by a flow of warm shallow water into the northern North Atlantic which is responsible for the anomalous warm climate in Europe. Changes in the formation of NADW have been linked to global climate changes in the past. Since human-made substances were introduced into the environment, the path of the NADW can be traced throughout its course by measuring tritium and radiocarbon from nuclear weapon tests in

756-498: Is found off the eastern coast of Canada. Surface water temperatures, which vary with latitude, current systems, and season and reflect the latitudinal distribution of solar energy, range from below −2 °C (28 °F) to over 30 °C (86 °F). Maximum temperatures occur north of the equator, and minimum values are found in the polar regions. In the middle latitudes, the area of maximum temperature variations, values may vary by 7–8 °C (13–14 °F). From October to June

840-575: Is interrupted by larger transform faults at two places: the Romanche Trench near the Equator and the Gibbs fracture zone at 53°N . The MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the other. 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

924-854: 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 . 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 . In

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1008-729: Is now northern and central Brazil. The formation of the Central American Isthmus closed the Central American Seaway at the end of the Pliocene 2.8 Ma ago. 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

1092-794: Is now the Carpathian region, that were similar to the Sargasso Sea. It is possible that the population in the Sargasso Sea migrated to the Atlantic as the Tethys closed at the end of the Miocene around 17 Ma. The origin of the Sargasso fauna and flora remained enigmatic for centuries. The fossils found in the Carpathians in the mid-20th century often called the "quasi-Sargasso assemblage", finally showed that this assemblage originated in

1176-520: The Age of Discovery , the Atlantic was also known to English cartographers as the Great Western Ocean . The pond is a term often used by British and American speakers in reference to the northern Atlantic Ocean, as a form of meiosis , or ironic understatement. It is used mostly when referring to events or circumstances "on this side of the pond" or "on the other side of the pond" or "across

1260-564: The Carpathian Basin from where it migrated over Sicily to the central Atlantic where it evolved into modern species of the Sargasso Sea. The location of the spawning ground for European eels remained unknown for decades . 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

1344-703: The Guantanamo Bay Naval Base , dependents were evacuated to the United States on 22 October, and Marine units were shipped by air and sea to reinforce the base. Task Force 135, including the carrier USS  Enterprise , was sent to the south of Cuba, ready to join in the defense of the Guantanamo Bay base if needed. The carrier USS  Independence and the supporting ships of Carrier Division Six stood by to provide additional support. Antisubmarine forces were redeployed to cover

1428-474: The Icelandic Low produces frequent storms. Icebergs are common from early February to the end of July across the shipping lanes near the Grand Banks of Newfoundland . The ice season is longer in the polar regions, but there is little shipping in those areas. Hurricanes are a hazard in the western parts of the North Atlantic during the summer and autumn. Due to a consistently strong wind shear and

1512-534: The Maritime Prepositioning ship and underway replenishment fleets, and a further three amphibious operations ships also participated. During the evacuation of Hurricane Irene in August 2011, the fleet evacuated to the safety of the open ocean. On 21 August 2010, it was reported that Secretary Robert Gates was considering disestablishing Second Fleet. On 6 January 2011, it was reported via

1596-684: The North American and Eurasian plates in the North Atlantic and the South American and African plates in the South Atlantic. The MAR produces basaltic volcanoes in Eyjafjallajökull , Iceland, and pillow lava on the ocean floor. 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. The MAR

1680-616: The North Atlantic Drift is thought to have at least some influence on climate. 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 Gulf Stream also keeps extreme temperatures from occurring on the Florida Peninsula. In the higher latitudes, the North Atlantic Drift, warms

1764-514: The North Atlantic oscillation , occurs. On average, the Atlantic is the saltiest major ocean; surface water salinity in the open ocean ranges from 33 to 37 parts per thousand (3.3–3.7%) by mass and varies with latitude and season. Evaporation, precipitation, river inflow and sea ice melting influence surface salinity values. Although the lowest salinity values are just north of the equator (because of heavy tropical rainfall), in general,

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1848-555: The Scotia Sea , and other tributary water bodies. Including these marginal seas the coast line of the Atlantic measures 111,866 km (69,510 mi) compared to 135,663 km (84,297 mi) for the Pacific. Including its marginal seas, the Atlantic covers an area of 106,460,000 km (41,100,000 sq mi) or 23.5% of the global ocean and has a volume of 310,410,900 km (74,471,500 cu mi) or 23.3% of

1932-619: 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 . On the other hand, to early Greek sailors and in ancient Greek mythological literature such as the Iliad and the Odyssey , this all-encompassing ocean was instead known as Oceanus , the gigantic river that encircled the world; in contrast to

2016-496: The United States Coast Guard . When activated, Joint Task Force 120 was tasked to execute a variety of contingency missions. Commander Second Fleet oversaw several subordinate task forces, which were activated as needed. Additionally, Commander, Second Fleet was the immediate superior to a number of Carrier Strike Groups , Expeditionary Strike Group 2, Commander Strike Force Training Atlantic , as well as

2100-729: The United States East Coast . As of 2008, the Commander, Second Fleet (COMSECONDFLT), under the Commander, U.S. Fleet Forces Command (CUSFFC), was also designated as Commander, Task Force 20 . CTF-20 planned for, and when directed, conducted battle force operations in the Atlantic command in support of designated unified or allied commanders. CTF-20 directed movements and exercised operational control of USFFC assigned units to carry out scheduled ocean transits and other special operations as directed, in order to maximize fleet operational readiness to respond to contingencies in

2184-638: The meridional overturning circulation (MOC), the northward heat transport of which is threatened by anthropogenic climate change. 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. The South Atlantic is dominated by the anti-cyclonic southern subtropical gyre. The South Atlantic Central Water originates in this gyre, while Antarctic Intermediate Water originates in

2268-458: The thermocline of the subtropical gyre. The Sargasso Sea in the western North Atlantic can be defined as the area where two species of Sargassum ( S. fluitans and natans ) float, an area 4,000 km (2,500 mi) wide and encircled by the Gulf Stream , North Atlantic Drift , and North Equatorial Current . This population of seaweed probably originated from Tertiary ancestors on

2352-578: The 1870s, the Challenger expedition discovered parts of what is now known as the Mid-Atlantic Ridge, or: An elevated ridge rising to an average height of about 1,900 fathoms [3,500 m; 11,400 ft] below the surface traverses the basins of the North and South Atlantic in a meridianal direction from Cape Farewell, probably its far south at least as Gough Island, following roughly

2436-618: The 1953 definition it extends south to Antarctica, while in later maps it is bounded at the 60° parallel by the Southern Ocean. The Atlantic has irregular coasts indented by numerous bays, gulfs and seas. 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

2520-485: The 1960s and CFCs . The clockwise warm-water North Atlantic Gyre occupies the northern Atlantic, and the counter-clockwise warm-water South Atlantic Gyre appears in the southern Atlantic. 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 ,

2604-488: The Atlantic and Pacific. Marine organisms on both sides of the isthmus became isolated and either diverged or went extinct. Western Hemisphere Group The Western Hemisphere Group was a United States Navy formation active from 1 September 1995 to 1999–2000. Headquarters was at Naval Station Mayport , Florida. In 1996 a U.S. Navy study said that "the recently created Western Hemisphere Group, composed of 16 naval surface ships—including two Aegis cruisers-serves as

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2688-537: The Atlantic are wide off Newfoundland, southernmost South America, and northeastern Europe. In the western Atlantic carbonate platforms dominate large areas, for example, the Blake Plateau and Bermuda Rise . 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

2772-401: The Atlantic command area of operations. In order to command and control its forces, CTF-20 maintained a Joint Maritime Operations Center at its Maritime Headquarters, which was officially said to offer a new approach to command and control for fleet commanders. Until 2005, COMSECONDFLT had a permanent assignment with NATO 's Supreme Allied Commander Atlantic 's (SACLANT) chain of command , as

2856-625: The Atlantic include the Challenger expedition and the German Meteor expedition ; as of 2001 , Columbia University 's Lamont–Doherty Earth Observatory and the United States Navy Hydrographic Office conduct research on the ocean. The MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2,000 m (6,600 ft) along most of its length, but

2940-403: The Atlantic north of the equator. The coldest zones are in high latitudes, with the coldest regions corresponding to the areas covered by sea ice. Ocean currents influence the climate by transporting warm and cold waters to other regions. The winds that are cooled or warmed when blowing over these currents influence adjacent land areas. The Gulf Stream and its northern extension towards Europe,

3024-469: The Atlantic sea ' , etym . ' Sea of Atlas ' ) and in The Histories of Herodotus around 450 BC (Hdt. 1.202.4): Atlantis thalassa (Ancient Greek: Ἀτλαντὶς θάλασσα , ' Sea of Atlas ' or ' the Atlantic sea ' ) where the name refers to "the sea beyond the pillars of Heracles " which is said to be part of the sea that surrounds all land. In these uses, the name refers to Atlas ,

3108-548: The Atlantic". Perry said it sends the message that "we understand we are in a battle for the Atlantic, and we will contest it." The Navy declared 2nd Fleet fully operational on 31 December 2019. During Exercise Steadfast Defender '21, Canadian Rear Admiral Steve Waddell, vice commander, Second Fleet, served as commander of C2F’s forward-deployed Task Force 20. On May 26, 2021, the U.S. Navy announced that Rear Admiral (lower half) Brian L. Davies would be assigned additional duties as deputy commander, Second Fleet, Norfolk, Virginia. He

3192-784: The Atlantic, it was the expedition of Christopher Columbus in 1492 that proved to be the most consequential. Columbus' expedition ushered in an age of exploration and colonization of the Americas by European powers , most notably Portugal , Spain , France , and the United Kingdom . From the 16th to 19th centuries, the Atlantic Ocean was the center of both an eponymous slave trade and the Columbian exchange while occasionally hosting naval battles. Such naval battles, as well as growing trade from regional American powers like

3276-633: The Bahamas, while coarse river outwash sands and silt are common in shallow shelf areas like the Georges Bank . Coarse sand, boulders, and rocks were transported into some areas, such as off the coast of Nova Scotia or the Gulf of Maine during the Pleistocene ice ages. The break-up of Pangaea began in the central Atlantic, between North America and Northwest Africa, where rift basins opened during

3360-781: The Combined Joint Operations from the Sea Center of Excellence located at the Second Fleet headquarters. During its existence, Second Fleet was responsible for training and certifying Atlantic Fleet units for forward deployment to other numbered fleets, primarily U.S. Fourth Fleet , U.S. Fifth Fleet , and U.S. Sixth Fleet . Second Fleet's main training and certification venues were the Composite Unit Training Exercise (COMTUEX) and Joint Task Force Exercise (JTFEX), conducted off

3444-513: The Commander Striking Fleet Atlantic (COMSTRIKFLTLANT). COMSTRIKFLTLANT commanded a multinational force whose primary mission was to deter aggression and to protect NATO 's Atlantic interests. Striking Fleet Atlantic was tasked with ensuring the integrity of NATO's sea lines of communication . STRIKFLTLANT was deactivated in a ceremony to be held on USS  Iwo Jima  (LHD-7) on 24 June 2005, being replaced by

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3528-505: The Commander for Joint Force Command for the Atlantic that will report to the Supreme Allied Commander Europe . This Joint Forces Command is formally known as Joint Force Command Norfolk . Rear Adm. Doug Perry, director of joint and fleet operations at Fleet Forces Command, was quoted in early November 2018 that the fleet was reformed because "the Navy needed a commander to direct sustained combat operations in

3612-516: The European shores of the former Tethys Ocean and has, if so, maintained itself by vegetative growth , floating in the ocean for millions of years. Other species endemic to the Sargasso Sea include the sargassum fish , a predator with algae-like appendages which hovers motionless among the Sargassum . Fossils of similar fishes have been found in fossil bays of the former Tethys Ocean, in what

3696-623: The Late Triassic and Early Jurassic. This period also saw the first stages of the uplift of the Atlas Mountains. The exact timing is controversial with estimates ranging from 200 to 170 Ma. 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

3780-539: The North Atlantic Gyre, the cyclonic North Atlantic Subpolar Gyre plays a key role in climate variability. It is governed by ocean currents from marginal seas and regional topography, rather than being steered by wind, both in the deep ocean and at sea level. The subpolar gyre forms an important part of the global thermohaline circulation . Its eastern portion includes eddying branches of the North Atlantic Current which transport warm, saline waters from

3864-1012: The Sea Center of Excellence . On 1 July 2008, the Navy re-established the United States Fourth Fleet , based at Naval Station Mayport in Jacksonville, Florida , which then assumed responsibility for U.S. Navy ships, aircraft and submarines operating in the Caribbean Sea and the waters of Central and South America. In the aftermath of the 2010 Haiti earthquake , Second Fleet dispatched 17 ships, 48 helicopters, 12 fixed-wing aircraft and over 10,000 sailors and Marines in support of Humanitarian Assistance/Disaster Response. Second Fleet units conducted 336 air deliveries, delivered 32,400 US gallons (123,000 L; 27,000 imp gal) of water, 111,082 meals and 9,000 lb (4,100 kg) of medical supplies. Hospital ship USNS  Comfort , as well as survey vessels, ferries, elements of

3948-434: The Second Fleet to the Caribbean to lead the invasion of Grenada during Operation Urgent Fury . Leading joint forces, Vice Admiral Joseph Metcalf, III , COMSECONDFLT, became Commander, Joint Task Force 120 (CJTF 120), and commanded units from the Air Force , Army , Navy , and the Marine Corps . The amphibious force for the operation was made up of Amphibious Squadron 4 (the amphibious assault ship USS  Guam ,

4032-437: The South Atlantic, and the "Atmospheric Bridge", which evaporates subtropical Atlantic waters and exports it to the Pacific. The Atlantic Ocean consists of four major, upper water masses with distinct temperature and salinity. The Atlantic subarctic upper water in the northernmost North Atlantic is the source for subarctic intermediate water and North Atlantic intermediate water. North Atlantic central water can be divided into

4116-457: The Standing Navy Command Element (COMSTANDNAV CE), a deployable command element that has served multiple rotations as the headquarters of Combined Joint Task Force-Horn of Africa . In October 1996 COMSECONDFLT created Task Force 28, consisting of independent deployers operating in both the Caribbean Sea and Eastern Pacific. Commander, Western Hemisphere Group was assigned as Commander Task Force 28 (CTF 28). This arrangement assigned COMWESTHEMGRU

4200-538: The United States East Coast and in the northern Atlantic Ocean, as well as plan and conduct maritime, joint, and combined operations and train, certify and provide maritime forces to respond to global contingencies. Commander, Second Fleet will report to United States Fleet Forces Command . Vice Admiral Andrew L. Lewis was confirmed on 18 June 2018 as Commander, U.S. 2nd Fleet. Second Fleet was reactivated in Norfolk on 1 July 2018 and received formal establishment on 24 August 2018. Commander Second Fleet will be dual-hatted as

4284-404: The United States and Brazil , both increased in degree during the early 20th century, and while no major military conflicts have taken place in the Atlantic recently, the ocean remains a core component of trade around the world. The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, and the Americas to the west. As one component of

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4368-463: The amphibious transport dock USS  Trenton , the dock landing ship USS  Fort Snelling , and the tank landing ships USS  Manitowoc and USS  Barnstable County ) and the 22nd Marine Amphibious Unit , built around 2nd Battalion, 8th Marines . Vice Admiral Metcalf assigned to the amphibious force, designated Task Force 124, the mission of seizing the Pearls Airport and the port of Grenville, and of neutralizing any opposing forces in

4452-421: The area. Simultaneously, Army Rangers (Task Force 121)— together with elements of the 82d Airborne Division (Task Force 123)— would secure points at the southern end of the island, including the nearly completed jet airfield under construction near Point Salines. Task Group 20.5, a carrier battle group build around USS  Independence  (CV-62) and Air Force elements would support the ground forces. Before

4536-412: The atmosphere over the oceans, keeping the British Isles and northwestern Europe mild and cloudy, and not severely cold in winter, like other locations at the same high latitude. The cold water currents contribute to heavy fog off the coast of eastern Canada (the Grand Banks of Newfoundland area) and Africa's northwestern coast. In general, winds transport moisture and air over land areas. Every winter,

4620-417: The beginning of the Gulf War in January 1991, Second Fleet trained more than half of the Navy ships deployed to Southwest Asia. On 22 February 2005/24 June 2005, with the establishment of Allied Command Transformation , and in the total absence of the Soviet threat that had prompted its creation, the Striking Fleet Atlantic nucleus was disbanded. It was replaced in 2006 by the Combined Joint Operations from

4704-431: The east, the boundaries of the ocean proper are Europe: the Strait of Gibraltar (where it connects with the Mediterranean Sea  – one of its marginal seas  – and, in turn, the Black Sea , both of which also touch upon Asia) and Africa. In the southeast, the Atlantic merges into the Indian Ocean. The 20° East meridian , running south from Cape Agulhas to Antarctica defines its border. In

4788-567: The eastern U.S. coast from Virginia to Florida. These exercises serve as a ready-for-deployment certification events for Carrier Strike Groups , Amphibious ready groups , as well as independently deploying units. In times of crisis and during certain exercises, Second Fleet became the Commander, Joint Task Force 120 . This joint task force consists of elements of the Atlantic Fleet, U.S. Army quick reaction airborne and air assault units, U.S. Air Force aircraft and support personnel, U.S. Marine Corps amphibious forces, and at times, designated units of

4872-544: The eastern and western North Atlantic central water since the western part is strongly affected by the Gulf Stream and therefore the upper layer is closer to underlying fresher subpolar intermediate water. The eastern water is saltier because of its proximity to Mediterranean water. North Atlantic central water flows into South Atlantic central water at 15°N . There are five intermediate waters: four low-salinity waters formed at subpolar latitudes and one high-salinity formed through evaporation. Arctic intermediate water flows from

4956-400: The enclosed seas well known to the Greeks: the Mediterranean and the Black Sea. In contrast, the term "Atlantic" originally referred specifically to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the West African coast. The term " Aethiopian Ocean ", derived from Ancient Ethiopia , was applied to the southern Atlantic as late as the mid-19th century. During

5040-568: The interconnected World Ocean , it is connected in the north to the Arctic Ocean , to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south. Other definitions describe the Atlantic as extending southward to Antarctica . The Atlantic Ocean is divided in two parts, the northern and southern Atlantic, by the Equator . The oldest known mentions of an "Atlantic" sea come from Stesichorus around mid-sixth century BC (Sch. A. R. 1. 211): Atlantikôi pelágei (Ancient Greek: Ἀτλαντικῷ πελάγει , '

5124-454: The latter 2,000 km (1,200 mi). Ocean currents such as the Gulf Stream transport eel larvae from the Sargasso Sea to foraging areas in North America, Europe, and northern Africa. Recent but disputed research suggests that eels possibly use Earth's magnetic field to navigate through the ocean both as larvae and as adults. The climate is influenced by the temperatures of the surface waters and water currents as well as winds. Because of

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5208-474: The limits of the oceans and seas in 1953, but some of these definitions have been revised since then and some are not recognized by various authorities, institutions, and countries, for example the CIA World Factbook . Correspondingly, the extent and number of oceans and seas vary. The Atlantic Ocean is bounded on the west by North and South America. It connects to the Arctic Ocean through the Denmark Strait , Greenland Sea , Norwegian Sea and Barents Sea . To

5292-429: The lowest values are in the high latitudes and along coasts where large rivers enter. Maximum salinity values occur at about 25° north and south , in subtropical regions with low rainfall and high evaporation. The high surface salinity in the Atlantic, on which the Atlantic thermohaline circulation is dependent, is maintained by two processes: the Agulhas Leakage/Rings , which brings salty Indian Ocean waters into

5376-454: The margins of the continents constitute about 11% of the bottom topography with few deep channels cut across the continental rise. The mean depth between 60°N and 60°S is 3,730 m (12,240 ft), or close to the average for the global ocean, with a modal depth between 4,000 and 5,000 m (13,000 and 16,000 ft). In the South Atlantic the Walvis Ridge and Rio Grande Rise form barriers to ocean currents. The Laurentian Abyss

5460-407: The maximum depth, the Milwaukee Deep in the Puerto Rico Trench , is 8,376 m (27,480 ft). Top large seas: The bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge (MAR). It runs from 87°N or 300 km (190 mi) south of the North Pole to the subantarctic Bouvet Island at 54°S . Expeditions to explore the bathymertry of

5544-510: 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 . 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 extent of the volcanism has been estimated to 4.5 × 10  km (1.7 × 10  sq mi) of which 2.5 × 10  km (9.7 × 10  sq mi) covered what

5628-502: The north to become the source for North Atlantic deep water, south of the Greenland-Scotland sill. These two intermediate waters have different salinity in the western and eastern basins. The wide range of salinities in the North Atlantic is caused by the asymmetry of the northern subtropical gyre and a large number of contributions from a wide range of sources: Labrador Sea, Norwegian-Greenland Sea, Mediterranean, and South Atlantic Intermediate Water. The North Atlantic deep water (NADW)

5712-425: The ocean's great capacity to store and release heat, maritime climates are more moderate and have less extreme seasonal variations than inland climates. Precipitation can be approximated from coastal weather data and air temperature from water temperatures. The oceans are the major source of atmospheric moisture that is obtained through evaporation. Climatic zones vary with latitude; the warmest zones stretch across

5796-456: The operational center of gravity for future naval strategy in the Western Hemisphere;" and that "the Western Hemisphere Group will serve primarily as the naval forces component (CTF 125 [Commander Task Force 125]) to COMSECONDFLT (JTF120 [Joint Task Force 120]) and will train for operations in support of theater objectives." In October 1996 Commander U.S. Second Fleet created Task Force 28, consisting of independent deployers operating in both

5880-401: The operational control (OPCON) of these Second Fleet destroyers. The U.S. Second Fleet traces its origin to the reorganization of the Navy following World War II in December 1945 and the formation of the United States Eighth Fleet under the command of Vice Admiral Marc A. Mitscher . In January 1947, Eighth Fleet was renamed Second Task Fleet. Three years later, in February 1950, the command

5964-457: The outlines of the coasts of the Old and the New Worlds. The remainder of the ridge was discovered in the 1920s by the German Meteor expedition using echo-sounding equipment. The exploration of the MAR in the 1950s led to the general acceptance of seafloor spreading and plate tectonics . Most of the MAR runs under water but where it reaches the surfaces it has produced volcanic islands. While nine of these have collectively been nominated

6048-595: The pond", rather than to discuss the ocean itself. The term dates to 1640, first appearing in print in a pamphlet released during the reign of Charles I , and reproduced in 1869 in Nehemiah Wallington 's Historical Notices of Events Occurring Chiefly in The Reign of Charles I , where "great Pond" is used in reference to the Atlantic Ocean by Francis Windebank , Charles I's Secretary of State . The International Hydrographic Organization (IHO) defined

6132-600: The quarantine force was assigned to the Commander of the Second Fleet, Vice Admiral Alfred G. Ward , who organized Task Force 136 for this purpose. Task Force 136 included the support carrier USS Essex . Effective deployment constituted a mammoth task to be accomplished in minimum time. To prevent future difficulties, plans had to be developed, ship captains briefed, supply ships dispatched, and thousands of details checked. Other Navy and Marine forces faced similar tough schedules. Marines, if not already engaged in landing exercises, were loaded on amphibious ships and ordered to sea. At

6216-702: The quarantine operations. An intensive air surveillance of the Atlantic was initiated, keeping track of the 2,000 commercial ships usually in the area; regular and reserve Navy aircraft were joined in this search by SAC bombers. Major exercises the fleet participated in during the Cold War included Exercise Mariner , Operation Strikeback in 1957, the maritime component of Exercise Reforger , and Northern Wedding . From 9 to 12 February 1978, Task Group 21.6 ( USS  Inchon and USS Spruance ) visited Monrovia in Liberia . In 1983, President Ronald Reagan ordered

6300-677: The reestablishment of the Second Fleet. Pentagon spokesman Johnny Michael said, "NATO is refocusing on the Atlantic in recognition of the great power competition prompted by a resurgent Russia". It was reestablished on 24 August 2018, with Vice Admiral Andrew "Woody" Lewis in command. Second Fleet was scheduled to resume operations officially on 1 July 2018, initially with a staff of 15 personnel (11 officers and four enlisted personnel), although plans call for its work force to expand to 256 (85 officers, 164 enlisted personnel, and seven civilians). It will exercise operational and administrative authorities over assigned ships, aircraft, and landing forces on

6384-438: The seafloor. The oldest oceanic crust in the Atlantic is up to 145 million years and is situated off the west coast of Africa and the east coast of North America, or on either side of the South Atlantic. In many places, the continental shelf and continental slope are covered in thick sedimentary layers. For instance, on the North American side of the ocean, large carbonate deposits formed in warm shallow waters such as Florida and

6468-551: The subtropics to the northeastern Atlantic. There this water is cooled during winter and forms return currents that merge along the eastern continental slope of Greenland where they form an intense (40–50  Sv ) current which flows around the continental margins of the Labrador Sea . A third of this water becomes part of the deep portion of the North Atlantic Deep Water (NADW). The NADW, in turn, feeds

6552-421: The surface is usually covered with sea ice in the Labrador Sea , Denmark Strait , and Baltic Sea. The Coriolis effect circulates North Atlantic water in a clockwise direction, whereas South Atlantic water circulates counter-clockwise. The south tides in the Atlantic Ocean are semi-diurnal; that is, two high tides occur every 24 lunar hours. In latitudes above 40° North some east–west oscillation, known as

6636-480: The total volume of the Earth's oceans. Excluding its marginal seas, the Atlantic covers 81,760,000 km (31,570,000 sq mi) and has a volume of 305,811,900 km (73,368,200 cu mi). The North Atlantic covers 41,490,000 km (16,020,000 sq mi) (11.5%) and the South Atlantic 40,270,000 km (15,550,000 sq mi) (11.1%). The average depth is 3,646 m (11,962 ft) and

6720-636: The upper layers of the circumpolar region, near the Drake Passage and the Falkland Islands. Both these currents receive some contribution from the Indian Ocean. On the African east coast, the small cyclonic Angola Gyre lies embedded in the large subtropical gyre. The southern subtropical gyre is partly masked by a wind-induced Ekman layer . The residence time of the gyre is 4.4–8.5 years. North Atlantic Deep Water flows southward below

6804-424: The western Atlantic and South Sandwich Trench (8,264 m or 27,113 ft) in the South Atlantic. There are numerous submarine canyons off northeastern North America, western Europe, and northwestern Africa. Some of these canyons extend along the continental rises and farther into the abyssal plains as deep-sea channels. In 1922, a historic moment in cartography and oceanography occurred. The USS Stewart used

6888-634: Was known for separating the New World of the Americas ( North America and South America ) from the Old World of Afro-Eurasia ( Africa , Asia , and Europe ). Through its separation of Afro-Eurasia from the Americas, the Atlantic Ocean has played a central role in the development of human society, globalization, and the histories of many nations. While the Norse were the first known humans to cross

6972-535: Was redesignated U.S. Second Fleet. Second Fleet's area of responsibility included the Atlantic coast of South America and part of the west coast of Central America . In October 1962, President John F. Kennedy called on Second Fleet to establish quarantine during the Cuban Missile Crisis . For more than a month, Second Fleet units operated northeast of the island, intercepting and inspecting dozens of ships for contraband. The operational control of

7056-412: Was to retain all currently assigned duties as Commander, Submarine Group 2 , Norfolk, Virginia. Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceanic divisions , with an area of about 85,133,000 km (32,870,000 sq mi). It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery , it

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