A continent is one of several very large landmasses. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in area to smallest, they are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.
Geologically, the continents largely correspond to areas of continental crust that are found on the continental plates. However, some areas of continental crust are regions covered with water not usually included in the list of continents. Zealandia is one such area (see submerged continents below). This type of landmass is only known to exist on Earth.
Islands are frequently grouped with a neighbouring continent to divide all the world's land into geopolitical regions. Under this scheme, most of the island countries and territories in the Pacific Ocean are grouped together with the continent of Australia to form a geopolitical region called Oceania.
By convention, "continents are understood to be large, continuous, discrete masses of land, ideally separated by expanses of water." Several of the seven conventionally recognized continents are not discrete landmasses separated completely by water. The criterion "large" leads to arbitrary classification: Greenland, with a surface area of 2,166,086 square kilometres (836,330 sq mi) is considered the world's largest island, while Australia, at 7,617,930 square kilometres (2,941,300 sq mi) is deemed the smallest continent.
The most restricted meaning of continent is that of a continuous area of land or mainland, with the coastline and any land boundaries forming the edge of the continent. In this sense the term continental Europe (sometimes referred to in Britain as "the Continent") is used to refer to mainland Europe, excluding islands such as Great Britain, Ireland, Malta and Iceland, and the term continent of Australia may refer to the mainland of Australia, excluding Tasmania and New Guinea. Similarly, the continental United States refers to the 48 contiguous states and the District of Columbia in central North America and may include Alaska in the northwest of the continent (the two being separated by Canada), while excluding Hawaii, Puerto Rico, and Guam in the oceans.
From the perspective of geology or physical geography, continent may be extended beyond the confines of continuous dry land to include the shallow, submerged adjacent area (the continental shelf) and the islands on the shelf (continental islands), as they are structurally part of the continent.
From this perspective, the edge of the continental shelf is the true edge of the continent, as shorelines vary with changes in sea level. In this sense the islands of Great Britain and Ireland are part of Europe, while Australia and the island of New Guinea together form a continent.
As a cultural construct, the concept of a continent may go beyond the continental shelf to include oceanic islands and continental fragments. In this way, Iceland is considered part of Europe and Madagascar part of Africa. Extrapolating the concept to its extreme, some geographers group the Australian continental plate with other islands in the Pacific into one continent called Oceania. This divides the entire land surface of Earth into continents or quasi-continents.
The ideal criterion that each continent is a discrete landmass is commonly relaxed due to historical conventions. Of the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by the ocean. Several continents are defined not as absolutely distinct bodies but as "more or less discrete masses of land". Asia and Africa are joined by the Isthmus of Suez, and North and South America by the Isthmus of Panama. In both cases, there is no complete separation of these landmasses by water (disregarding the Suez Canal and Panama Canal, which are both narrow and shallow, as well as artificial). Both these isthmuses are very narrow compared to the bulk of the landmasses they unite.
North America and South America are treated as separate continents in the seven-continent model. However, they may also be viewed as a single continent known as America or the Americas. This viewpoint was common in the United States until World War II, and remains prevalent in some Asian six-continent models. This remains the more common vision in Latin American countries, Spain, Portugal, France, Italy, Greece and Hungary where they are taught as a single continent.
The criterion of a discrete landmass is completely disregarded if the continuous landmass of Eurasia is classified as two separate continents: Europe and Asia. Physiographically, Europe and South Asia are peninsulas of the Eurasian landmass. However, Europe is widely considered a continent with its comparatively large land area of 10,180,000 square kilometres (3,930,000 sq mi), while South Asia, with less than half that area, is considered a subcontinent. The alternative view—in geology and geography—that Eurasia is a single continent results in a six-continent view of the world. Some view separation of Eurasia into Asia and Europe as a residue of Eurocentrism: "In physical, cultural and historical diversity, China and India are comparable to the entire European landmass, not to a single European country. [...]." However, for historical and cultural reasons, the view of Europe as a separate continent continues in several categorizations.
If continents are defined strictly as discrete landmasses, embracing all the contiguous land of a body, then Africa, Asia, and Europe form a single continent which may be referred to as Afro-Eurasia. This produces a four-continent model consisting of Afro-Eurasia, America, Antarctica and Australia.
When sea levels were lower during the Pleistocene ice ages, greater areas of continental shelf were exposed as dry land, forming land bridges. At those times Australia–New Guinea was a single, continuous continent. Likewise, the Americas and Afro-Eurasia were joined by the Bering land bridge. Other islands such as Great Britain were joined to the mainlands of their continents. At that time there were just three discrete continents: Afro-Eurasia-America, Antarctica, and Australia-New Guinea.
There are several ways of distinguishing the continents:
|Six continents||Africa||Eurasia||North America||South America||Antarctica||Australia/Oceania|||
|Seven continents||Africa||Asia||Europe||North America||South America||Antarctica||Australia/Oceania|||
The term Oceania refers to a group of island countries and territories in the Pacific Ocean, together with the continent of Australia. Pacific islands with ties to other continents (such as Japan, Hawaii or Easter Island) are usually grouped with those continents rather than Oceania. This term is used in several different continental models instead of Australia.
The following table summarizes the area and population of the continental regions used by the United Nations. These regions differ from the physical continents in various ways that are explained in the notes.
|Africa||[note 1]||30,370,000||11,730,000||20.4%||1,287,920,000||16.9%||Lagos, Nigeria|
|Antarctica||[note 2]||14,000,000||5,400,000||9.2%||4,490||0.0%||McMurdo Station|
|Asia||[note 3]||44,579,000||17,212,000||29.5%||4,545,133,000||59.5%||Shanghai, China|
|Europe||[note 4]||10,180,000||3,930,000||6.8%||742,648,000||9.7%||Moscow, Russia|
|North America||[note 5]||24,709,000||9,540,000||16.5%||587,615,000||7.7%||Mexico City, Mexico|
|Australia||[note 6]||8,600,000||3,300,000||5.9%||41,261,000||0.5%||Sydney, Australia|
|South America||17,840,000||6,890,000||12.0%||428,240,000||5.6%||São Paulo, Brazil|
The total land area of all continents is 148,647,000 square kilometres (57,393,000 sq mi), or 29.1% of earth's surface (510,065,600 km2 or 196,937,400 sq mi).
Aside from the conventionally known continents, the scope and meaning of the term continent varies. Supercontinents, largely in evidence earlier in the geological record, are landmasses that comprise more than one craton or continental core. These have included Laurasia, Gondwana, Vaalbara, Kenorland, Columbia, Rodinia, Pangaea. Over time, these supercontinents broke apart into large land masses which caused the formation of our present continents.
Certain parts of continents are recognized as subcontinents, especially the large peninsulas separated from the main continental landmass by geographical features. The most notable examples are the Indian subcontinent and the Arabian Peninsula. The Southern Cone of South America and Alaskan peninsula of North America are other examples.
In many of these cases, the "subcontinents" concerned are on different tectonic plates from the rest of the continent, providing a geological justification for the terminology. Greenland, generally reckoned as the world's largest island on the northeastern periphery of the North American Plate, is sometimes referred to as a subcontinent. This is a significant departure from the more conventional view of a subcontinent as comprising a very large peninsula on the fringe of a continent.
Where the Americas are viewed as a single continent (America), it is divided into two subcontinents (North America and South America) or three (with Central America being the third). When Eurasia is regarded as a single continent, Europe is treated as a subcontinent.
Some areas of continental crust are largely covered by the sea and may be considered submerged continents. Notable examples are Zealandia, emerging from the sea primarily in New Zealand and New Caledonia, and the almost completely submerged Kerguelen Plateau in the southern Indian Ocean.
Some islands lie on sections of continental crust that have rifted and drifted apart from a main continental landmass. While not considered continents because of their relatively small size, they may be considered microcontinents. Madagascar, the largest example, is usually considered an island of Africa, but its divergent evolution has caused it to be referred to as "the eighth continent" from a biological perspective.
"Continents" may be defined differently for specific purposes. The Biodiversity Information Standards organization has developed the World Geographical Scheme for Recording Plant Distributions, used in many international plant databases. This scheme divides the world into nine "botanical continents". Some match the traditional geographical continents, but some differ significantly. Thus the Americas are divided between Northern America (Mexico northwards) and Southern America (Central America and the Caribbean southwards) rather than between North America and South America.
The term "continent" translates Greek ἤπειρος, properly "landmass, terra firma", the proper name of Epirus and later especially used of Asia (i.e. Asia Minor), The first distinction between continents was made by ancient Greek mariners who gave the names Europe and Asia to the lands on either side of the waterways of the Aegean Sea, the Dardanelles strait, the Sea of Marmara, the Bosporus strait and the Black Sea. The names were first applied just to lands near the coast and only later extended to include the hinterlands. But the division was only carried through to the end of navigable waterways and "... beyond that point the Hellenic geographers never succeeded in laying their finger on any inland feature in the physical landscape that could offer any convincing line for partitioning an indivisible Eurasia ..."
Ancient Greek thinkers subsequently debated whether Africa (then called Libya) should be considered part of Asia or a third part of the world. Division into three parts eventually came to predominate. From the Greek viewpoint, the Aegean Sea was the center of the world; Asia lay to the east, Europe to the north and west, and Africa to the south. The boundaries between the continents were not fixed. Early on, Europe–Asia boundary was taken to run from the Black Sea along the Rioni River (known then as the Phasis) in Georgia. Later it was viewed as running from the Black Sea through Kerch Strait, the Sea of Azov and along the Don River (known then as the Tanais) in Russia. The boundary between Asia and Africa was generally taken to be the Nile River. Herodotus in the 5th century BC, however, objected to the unity of Egypt being split into Asia and Africa ("Libya") and took the boundary to lie along the western border of Egypt, regarding Egypt as part of Asia. He also questioned the division into three of what is really a single landmass, a debate that continues nearly two and a half millennia later.
Eratosthenes, in the 3rd century BC, noted that some geographers divided the continents by rivers (the Nile and the Don), thus considering them "islands". Others divided the continents by isthmuses, calling the continents "peninsulas". These latter geographers set the border between Europe and Asia at the isthmus between the Black Sea and the Caspian Sea, and the border between Asia and Africa at the isthmus between the Red Sea and the mouth of Lake Bardawil on the Mediterranean Sea.
Through the Roman period and the Middle Ages, a few writers took the Isthmus of Suez as the boundary between Asia and Africa, but most writers continued to consider it the Nile or the western border of Egypt (Gibbon). In the Middle Ages, the world was usually portrayed on T and O maps, with the T representing the waters dividing the three continents. By the middle of the 18th century, "the fashion of dividing Asia and Africa at the Nile, or at the Great Catabathmus [the boundary between Egypt and Libya] farther west, had even then scarcely passed away".
Christopher Columbus sailed across the Atlantic Ocean to the West Indies in 1492, sparking a period of European exploration of the Americas. But despite four voyages to the Americas, Columbus never believed he had reached a new continent—he always thought it was part of Asia.
In 1501, Amerigo Vespucci and Gonçalo Coelho attempted to sail around what they considered the southern end of the Asian mainland into the Indian Ocean, passing through Fernando de Noronha. After reaching the coast of Brazil, they sailed a long way further south along the coast of South America, confirming that this was a land of continental proportions and that it also extended much further south than Asia was known to. On return to Europe, an account of the voyage, called Mundus Novus ("New World"), was published under Vespucci's name in 1502 or 1503, although it seems that it had additions or alterations by another writer. Regardless of who penned the words, Mundus Novus credited Vespucci with saying, "I have discovered a continent in those southern regions that is inhabited by more numerous people and animals than our Europe, or Asia or Africa", the first known explicit identification of part of the Americas as a continent like the other three.
Within a few years, the name "New World" began appearing as a name for South America on world maps, such as the Oliveriana (Pesaro) map of around 1504–1505. Maps of this time though, still showed North America connected to Asia and showed South America as a separate land.
In 1507 Martin Waldseemüller published a world map, Universalis Cosmographia, which was the first to show North and South America as separate from Asia and surrounded by water. A small inset map above the main map explicitly showed for the first time the Americas being east of Asia and separated from Asia by an ocean, as opposed to just placing the Americas on the left end of the map and Asia on the right end. In the accompanying book Cosmographiae Introductio, Waldseemüller noted that the earth is divided into four parts, Europe, Asia, Africa and the fourth part, which he named "America" after Amerigo Vespucci's first name. On the map, the word "America" was placed on part of South America.
From the 16th century the English noun continent was derived from the term continent land, meaning continuous or connected land and translated from the Latin terra continens. The noun was used to mean "a connected or continuous tract of land" or mainland. It was not applied only to very large areas of land—in the 17th century, references were made to the continents (or mainlands) of Isle of Man, Ireland and Wales and in 1745 to Sumatra. The word continent was used in translating Greek and Latin writings about the three "parts" of the world, although in the original languages no word of exactly the same meaning as continent was used.
While continent was used on the one hand for relatively small areas of continuous land, on the other hand geographers again raised Herodotus's query about why a single large landmass should be divided into separate continents. In the mid-17th century, Peter Heylin wrote in his Cosmographie that "A Continent is a great quantity of Land, not separated by any Sea from the rest of the World, as the whole Continent of Europe, Asia, Africa." In 1727, Ephraim Chambers wrote in his Cyclopædia, "The world is ordinarily divided into two grand continents: the old and the new." And in his 1752 atlas, Emanuel Bowen defined a continent as "a large space of dry land comprehending many countries all joined together, without any separation by water. Thus Europe, Asia, and Africa is one great continent, as America is another." However, the old idea of Europe, Asia and Africa as "parts" of the world ultimately persisted with these being regarded as separate continents.
From the late 18th century, some geographers started to regard North America and South America as two parts of the world, making five parts in total. Overall though, the fourfold division prevailed well into the 19th century.
Europeans discovered Australia in 1606, but for some time it was taken as part of Asia. By the late 18th century, some geographers considered it a continent in its own right, making it the sixth (or fifth for those still taking America as a single continent). In 1813, Samuel Butler wrote of Australia as "New Holland, an immense island, which some geographers dignify with the appellation of another continent" and the Oxford English Dictionary was just as equivocal some decades later. It was in the 1950s that the concept of Oceania as a “great division” of the world was replaced by the concept of Australia as a continent.
Antarctica was sighted in 1820 during the First Russian Antarctic Expedition and described as a continent by Charles Wilkes on the United States Exploring Expedition in 1838, the last continent identified, although a great "Antarctic" (antipodean) landmass had been anticipated for millennia. An 1849 atlas labelled Antarctica as a continent but few atlases did so until after World War II.
From the mid-19th century, atlases published in the United States more commonly treated North and South America as separate continents, while atlases published in Europe usually considered them one continent. However, it was still not uncommon for American atlases to treat them as one continent up until World War II. From the 1950s, most U.S. geographers divided the Americas into two continents. With the addition of Antarctica, this made the seven-continent model. However, this division of the Americas never appealed to Latin Americans, who saw their region spanning an América as a single landmass, and there the conception of six continents remains dominant, as it does in scattered other countries.
Some geographers regard Europe and Asia together as a single continent, dubbed Eurasia. In this model, the world is divided into six continents, with North America and South America considered separate continents.
Geologists use the term continent in a different manner from geographers. In geology a continent is defined by continental crust: a platform of metamorphic and igneous rock, largely of granitic composition. Some geologists restrict the term 'continent' to portions of the crust built around stable Precambrian "shield", typically 1.5 to 3.8 billion years old, called a craton. The craton itself is an accretionary complex of ancient mobile belts (mountain belts) from earlier cycles of subduction, continental collision and break-up from plate tectonic activity. An outward-thickening veneer of younger minimally deformed sedimentary rock covers much of the craton. The margins of geologic continents are characterized by currently active or relatively recently active mobile belts and deep troughs of accumulated marine or deltaic sediments. Beyond the margin, there is either a continental shelf and drop off to the basaltic ocean basin or the margin of another continent, depending on the current plate-tectonic setting of the continent. A continental boundary does not have to be a body of water. Over geologic time, continents are periodically submerged under large epicontinental seas, and continental collisions result in a continent becoming attached to another continent. The current geologic era is relatively anomalous in that so much of the continental areas are "high and dry"; that is, many parts of the continents that were once below sea level are now elevated well above it due to changes in sea levels and the subsequent uplifting of those continental areas from tectonic activity.
Some argue that continents are accretionary crustal "rafts" that, unlike the denser basaltic crust of the ocean basins, are not subjected to destruction through the plate tectonic process of subduction. This accounts for the great age of the rocks comprising the continental cratons. By this definition, Eastern Europe, India and some other regions could be regarded as continental masses distinct from the rest of Eurasia because they have separate ancient shield areas (i.e. East European craton and Indian craton). Younger mobile belts (such as the Ural Mountains and Himalayas) mark the boundaries between these regions and the rest of Eurasia.
There are many microcontinents, or continental fragments, that are built of continental crust but do not contain a craton. Some of these are fragments of Gondwana or other ancient cratonic continents: Zealandia, which includes New Zealand and New Caledonia; Madagascar; the northern Mascarene Plateau, which includes the Seychelles. Other islands, such as several in the Caribbean Sea, are composed largely of granitic rock as well, but all continents contain both granitic and basaltic crust, and there is no clear boundary as to which islands would be considered microcontinents under such a definition. The Kerguelen Plateau, for example, is largely volcanic, but is associated with the breakup of Gondwanaland and is considered a microcontinent, whereas volcanic Iceland and Hawaii are not. The British Isles, Sri Lanka, Borneo, and Newfoundland are margins of the Laurasian continent—only separated by inland seas flooding its margins.
Plate tectonics offers yet another way of defining continents. Today, Europe and most of Asia constitute the unified Eurasian Plate, which is approximately coincident with the geographic Eurasian continent excluding India, Arabia, and far eastern Russia. India contains a central shield, and the geologically recent Himalaya mobile belt forms its northern margin. North America and South America are separate continents, the connecting isthmus being largely the result of volcanism from relatively recent subduction tectonics. North American continental rocks extend to Greenland (a portion of the Canadian Shield), and in terms of plate boundaries, the North American plate includes the easternmost portion of the Asian landmass. Geologists do not use these facts to suggest that eastern Asia is part of the North American continent, even though the plate boundary extends there; the word continent is usually used in its geographic sense and additional definitions ("continental rocks," "plate boundaries") are used as appropriate.
The movement of plates has caused the formation and break-up of continents over time, including occasional formation of a supercontinent that contains most or all of the continents. The supercontinent Columbia or Nuna formed during a period of 2.0–1.8 billion years ago and broke up about 1.5–1.3 billion years ago. The supercontinent Rodinia is thought to have formed about 1 billion years ago and to have embodied most or all of Earth's continents, and broken up into eight continents around 600 million years ago. The eight continents later re-assembled into another supercontinent called Pangaea; Pangaea broke up into Laurasia (which became North America and Eurasia) and Gondwana (which became the remaining continents).
The following table lists the seven continents with their highest and lowest points on land, sorted in decreasing highest points.
|Continent||Highest point||Elevation (m)||Elevation (ft)||Country or territory containing highest point||Lowest point||Elevation (m)||Elevation (ft)||Country or territory containing lowest point|
|Asia||Mount Everest||8,848||29,029||Nepal||Dead Sea||−427||−1,401||Israel, Jordan and Palestine|
|South America||Aconcagua||6,960||22,830||Argentina||Laguna del Carbón||−105||−344||Argentina|
|North America||Denali||6,198||20,335||United States||Death Valley †||−86||−282||United States|
|Africa||Mount Kilimanjaro||5,895||19,341||Tanzania||Lake Assal||−155||−509||Djibouti|
|Europe||Mount Elbrus||5,642||18,510||Russia||Caspian Sea||−28||−92||Russia|
|Antarctica||Vinson Massif||4,892||16,050||(none)||Deep Lake, Vestfold Hills †||−50||−160||(none)|
|Australia||Puncak Jaya||4,884||16,024||Indonesia (Papua)||Lake Eyre||−15||−49||Australia|
† The lowest exposed points are given for North America and Antarctica. The lowest non-submarine bedrock elevations in these continents are the trough beneath Jakobshavn Glacier (−1,512 metres (−4,961 ft)) and Bentley Subglacial Trench (−2,540 metres (−8,330 ft)), but these are covered by kilometers of ice.
Some sources list the Kuma–Manych Depression (a remnant of the Paratethys) as the geological border between Europe and Asia. This would place the Caucasus outside of Europe, thus making Mont Blanc (elevation 4810 m) in the Graian Alps the highest point in Europe – the lowest point would still be the shore of the Caspian Sea.
structurally it includes shallowly submerged adjacent areas (continental shelf) and neighbouring islands
And since Africa and Asia are connected at the Suez Peninsula, Europe, Africa, and Asia are sometimes combined as Afro-Eurasia or Eurafrasia.
the five interlaced rings, which represent the union of the five continents
Africa is the world's second largest and second most-populous continent. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area. With
1.2 billion people as of 2016, it accounts for about 16% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, the Isthmus of Suez and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It contains 54 fully recognised sovereign states (countries), nine territories and two de facto independent states with limited or no recognition. The majority of the continent and its countries are in the Northern Hemisphere, with a substantial portion and number of countries in the Southern Hemisphere.
Africa's average population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Algeria is Africa's largest country by area, and Nigeria is its largest by population. Africa, particularly central Eastern Africa, is widely accepted as the place of origin of humans and the Hominidae clade (great apes), as evidenced by the discovery of the earliest hominids and their ancestors as well as later ones that have been dated to around 7 million years ago, including Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis and H. ergaster—the earliest Homo sapiens (modern human), found in Ethiopia, date to circa 200,000 years ago. Africa straddles the equator and encompasses numerous climate areas; it is the only continent to stretch from the northern temperate to southern temperate zones.Africa hosts a large diversity of ethnicities, cultures and languages. In the late 19th century, European countries colonised almost all of Africa; most present states in Africa emerged from a process of decolonisation in the 20th century. African nations cooperate through the establishment of the African Union, which is headquartered in Addis Ababa.Americas
The Americas (also collectively called America; French: Amérique, Dutch: Amerika, Spanish and Portuguese: América) comprise the totality of the continents of North and South America. Together, they make up most of the land in Earth's western hemisphere and comprise the New World.
Along with their associated islands, they cover 8% of Earth's total surface area and 28.4% of its land area. The topography is dominated by the American Cordillera, a long chain of mountains that runs the length of the west coast. The flatter eastern side of the Americas is dominated by large river basins, such as the Amazon, St. Lawrence River / Great Lakes basin, Mississippi, and La Plata. Since the Americas extend 14,000 km (8,700 mi) from north to south, the climate and ecology vary widely, from the arctic tundra of Northern Canada, Greenland, and Alaska, to the tropical rain forests in Central America and South America.
Humans first settled the Americas from Asia between 42,000 and 17,000 years ago. A second migration of Na-Dene speakers followed later from Asia. The subsequent migration of the Inuit into the neoarctic around 3500 BCE completed what is generally regarded as the settlement by the indigenous peoples of the Americas.
The first known European settlement in the Americas was by the Norse explorer Leif Erikson. However, the colonization never became permanent and was later abandoned. The Spanish voyages of Christopher Columbus from 1492 to 1502 resulted in permanent contact with European (and subsequently, other Old World) powers, which led to the Columbian exchange and inaugurated a period of exploration, conquest, and colonization whose effects and consequences persist to the present. The Spanish presence involved the enslavement of large numbers of the indigenous population of America. During the first half of the 16th century, Spanish colonists conducted raids throughout the Caribbean Basin, bringing captives from Central America, northern South America, and Florida back to Hispaniola and other Spanish settlements.Diseases introduced from Europe and West Africa devastated the indigenous peoples, and the European powers colonized the Americas. Mass emigration from Europe, including large numbers of indentured servants, and importation of African slaves largely replaced the indigenous peoples.
Decolonization of the Americas began with the American Revolution in the 1770s and largely ended with the Spanish–American War in the late 1890s. Currently, almost all of the population of the Americas resides in independent countries; however, the legacy of the colonization and settlement by Europeans is that the Americas share many common cultural traits, most notably Christianity and the use of Indo-European languages: primarily Spanish, English, Portuguese, French, and, to a lesser extent, Dutch.
The Americas are home to over a billion inhabitants, two-thirds of whom reside in the United States, Brazil, and Mexico. It is home to eight megacities (metropolitan areas with ten million inhabitants or more): New York City (23.9 million), Mexico City (21.2 million), São Paulo (21.2 million), Los Angeles (18.8 million), Buenos Aires (15.6 million), Rio de Janeiro (13.0 million), Bogotá (10.4 million), and Lima (10.1 million).Antarctica
Antarctica (UK: or , US: (listen)) is Earth's southernmost continent. It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,200,000 square kilometres (5,500,000 square miles), it is the fifth-largest continent and nearly twice the size of Australia. At 0.00008 people per square kilometre, it is by far the least densely populated continent. About 98% of Antarctica is covered by ice that averages 1.9 km (1.2 mi; 6,200 ft) in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula.
Antarctica, on average, is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents. Most of Antarctica is a polar desert, with annual precipitation of 20 cm (7.9 in) along the coast and far less inland. The temperature in Antarctica has reached −89.2 °C (−128.6 °F) (or even −94.7 °C (−135.8 °F) as measured from space), though the average for the third quarter (the coldest part of the year) is −63 °C (−81 °F). Anywhere from 1,000 to 5,000 people reside throughout the year at research stations scattered across the continent. Organisms native to Antarctica include many types of algae, bacteria, fungi, plants, protista, and certain animals, such as mites, nematodes, penguins, seals and tardigrades. Vegetation, where it occurs, is tundra.
Antarctica is noted as the last region on Earth in recorded history to be discovered, unseen until 1820 when the Russian expedition of Fabian Gottlieb von Bellingshausen and Mikhail Lazarev on Vostok and Mirny sighted the Fimbul ice shelf. The continent, however, remained largely neglected for the rest of the 19th century because of its hostile environment, lack of easily accessible resources, and isolation. In 1895, the first confirmed landing was conducted by a team of Norwegians.
Antarctica is a de facto condominium, governed by parties to the Antarctic Treaty System that have consulting status. Twelve countries signed the Antarctic Treaty in 1959, and thirty-eight have signed it since then. The treaty prohibits military activities and mineral mining, prohibits nuclear explosions and nuclear waste disposal, supports scientific research, and protects the continent's ecozone. Ongoing experiments are conducted by more than 4,000 scientists from many nations.Asia
Asia ( (listen)) is Earth's largest and most populous continent, located primarily in the Eastern and Northern Hemispheres. It shares the continental landmass of Eurasia with the continent of Europe and the continental landmass of Afro-Eurasia with both Europe and Africa. Asia covers an area of 44,579,000 square kilometres (17,212,000 sq mi), about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but also dense and large settlements, as well as vast barely populated regions. Its 4.5 billion people (as of June 2019) constitute roughly 60% of the world's population.In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, and ethnic differences, some of which vary on a spectrum rather than with a sharp dividing line. The most commonly accepted boundaries place Asia to the east of the Suez Canal separating it from Africa; and to the east of the Turkish Straits, the Ural Mountains and Ural River, and to the south of the Caucasus Mountains and the Caspian and Black Seas, separating it from Europe.China and India alternated in being the largest economies in the world from 1 to 1800 CE. China was a major economic power and attracted many to the east, and for many the legendary wealth and prosperity of the ancient culture of India personified Asia, attracting European commerce, exploration and colonialism. The accidental discovery of a trans-Atlantic route from Europe to America by Columbus while in search for a route to India demonstrates this deep fascination. The Silk Road became the main east–west trading route in the Asian hinterlands while the Straits of Malacca stood as a major sea route. Asia has exhibited economic dynamism (particularly East Asia) as well as robust population growth during the 20th century, but overall population growth has since fallen. Asia was the birthplace of most of the world's mainstream religions including Hinduism, Zoroastrianism, Judaism, Jainism, Buddhism, Confucianism, Taoism, Christianity, Islam, Sikhism, as well as many other religions.
Given its size and diversity, the concept of Asia—a name dating back to classical antiquity—may actually have more to do with human geography than physical geography. Asia varies greatly across and within its regions with regard to ethnic groups, cultures, environments, economics, historical ties and government systems. It also has a mix of many different climates ranging from the equatorial south via the hot desert in the Middle East, temperate areas in the east and the continental centre to vast subarctic and polar areas in Siberia.Australasia
Australasia comprises Australia, New Zealand, and some neighbouring islands (see the section Derivations). It is used in a number of different contexts including geopolitically, physiogeographically, and ecologically where the term covers several slightly different but related regions.Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. It is the largest country in Oceania and the world's sixth-largest country by total area. The neighbouring countries are Papua New Guinea, Indonesia, and East Timor to the north; the Solomon Islands and Vanuatu to the north-east; and New Zealand to the south-east. The population of 26 million is highly urbanised and heavily concentrated on the eastern seaboard. Australia's capital is Canberra, and its largest city is Sydney. The country's other major metropolitan areas are Melbourne, Brisbane, Perth, and Adelaide.
Indigenous Australians inhabited the continent for about 65,000 years prior to European discovery with the arrival of Dutch explorers in the early 17th century, who named it New Holland. In 1770, Australia's eastern half was claimed by Great Britain and initially settled through penal transportation to the colony of New South Wales from 26 January 1788, a date which became Australia's national day. The population grew steadily in subsequent decades, and by the time of an 1850s gold rush, most of the continent had been explored and an additional five self-governing crown colonies established. On 1 January 1901, the six colonies federated, forming the Commonwealth of Australia. Australia has since maintained a stable liberal democratic political system that functions as a federal parliamentary constitutional monarchy, comprising six states and ten territories.
Being the oldest, flattest and driest inhabited continent, with the least fertile soils, Australia has a landmass of 7,617,930 square kilometres (2,941,300 sq mi). A megadiverse country, its size gives it a wide variety of landscapes, with deserts in the centre, tropical rainforests in the north-east and mountain ranges in the south-east. Its population density, 2.8 inhabitants per square kilometre, remains among the lowest in the world. Australia generates its income from various sources including mining-related exports, telecommunications, banking, and manufacturing.Australia is a highly developed country, with the world's 14th-largest economy. It has a high-income economy, with the world's tenth-highest per capita income. It is a regional power and has the world's 13th-highest military expenditure. Australia has the world's eighth-largest immigrant population, with immigrants accounting for 29% of the population. Having the third-highest human development index and the eighth-highest ranked democracy globally, the country ranks highly in quality of life, health, education, economic freedom, civil liberties and political rights, with all its major cities faring well in global comparative livability surveys. Australia is a member of the United Nations, G20, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development (OECD), World Trade Organization, Asia-Pacific Economic Cooperation, Pacific Islands Forum, and the ASEAN Plus Six mechanism.Australia (continent)
The continent of Australia, sometimes known in technical contexts by the names Sahul (), Australinea, Oceania or Meganesia to distinguish it from the country of Australia, consists of the land masses which sit on Australia's continental plate. This includes mainland Australia, Tasmania, and the island of New Guinea (comprising Papua New Guinea and two Indonesian provinces). Situated in the geographical region of Oceania, it is the smallest of the seven traditional continents in the English conception.
The continent includes a continental shelf overlain by shallow seas which divide it into several landmasses—the Arafura Sea and Torres Strait between mainland Australia and New Guinea, and Bass Strait between mainland Australia and Tasmania. When sea levels were lower during the Pleistocene ice age, including the Last Glacial Maximum about 18,000 BC, they were connected by dry land. During the past 10,000 years, rising sea levels overflowed the lowlands and separated the continent into today's low-lying arid to semi-arid mainland and the two mountainous islands of New Guinea and Tasmania.The Australian continent, being part of the Indo-Australian plate (more specifically, the Australian plate), is the lowest, flattest, and oldest landmass on Earth and it has had a relatively stable geological history. New Zealand is not part of the continent of Australia, but of the separate, submerged continent of Zealandia. New Zealand and Australia are both part of the Oceanian sub-region known as Australasia, with New Guinea being in Melanesia.
The term Oceania, originally a "great division" of the world, was replaced by the concept of Australia in the 1950s. Today, the term Oceania is often used to denote the region encompassing the Australian continent, Zealandia and various islands in the Pacific Ocean that are not included in the seven-continent model.Papua New Guinea, a country within the continent, is one of the most culturally and linguistically diverse countries in the world. It is also one of the most rural, as only 18
percent of its people live in urban centres. West Papua, a province of Indonesia, is home to an estimated 44 uncontacted tribal groups. Australia, the largest landmass in the continent, is highly urbanised, and has the world's 14th-largest economy with the second-highest human development index globally. Australia also has the world's 9th largest immigrant population. The first settlers of Australia, New Guinea, and the large islands just to the east arrived between 50,000 and 30,000 years ago.Continental Europe
Continental or mainland Europe is the continuous continent of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent – which can conversely mean the whole of Europe – and by Europeans, simply the Continent.
The most common definition of continental Europe excludes continental islands, encompassing the Greek Islands, Cyprus, Malta, Sicily, Sardinia, Corsica, the Balearic Islands, Great Britain and Ireland and surrounding islands, Novaya Zemlya and the Nordic archipelago, as well as nearby oceanic islands, including the Canary Islands, Madeira, the Azores, Iceland, the Faroe Islands, and Svalbard.
The Scandinavian Peninsula is sometimes also excluded, as even though it is technically part of "mainland Europe", the de facto connections to the rest of the continent are across the Baltic Sea or North Sea (rather than via the lengthy land route that involves travelling to the north of the peninsula where it meets Finland, and then south through north-east Europe).
The old notion of Europe as a cultural and European unification term was centred on core Europe (Kerneuropa), the continental territory of the historical Carolingian Empire, corresponding to modern France, Italy, Germany (or German-speaking Europe) and the Benelux states (historical Austrasia).
This historical core of "Carolingian Europe" was consciously invoked in the 1950s as the historical ethno-cultural basis for the prospective European integration (see also Multi-speed Europe).Continental drift
Continental drift is the theory that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected by many for lack of any motive mechanism. Arthur Holmes later proposed mantle convection for that mechanism. The idea of continental drift has since been subsumed by the theory of plate tectonics, which explains that the continents move by riding on plates of the Earth's lithosphere.Eurasia
Eurasia is the largest continent on Earth, comprising all of Europe and Asia. Located primarily in the Northern and Eastern Hemispheres, it is bordered by the Atlantic Ocean to the west, the Pacific Ocean to the east, the Arctic Ocean to the north, and by Africa, the Mediterranean Sea, and the Indian Ocean to the south. The division between Europe and Asia as two different continents is a historical social construct, with no clear physical separation between them; thus, in some parts of the world, Eurasia is recognized as the largest of the six, five, or even four continents on Earth. In geology, Eurasia is often considered as a single rigid megablock. However, the rigidity of Eurasia is debated based on paleomagnetic data.Eurasia covers around 55,000,000 square kilometres (21,000,000 sq mi), or around 36.2% of the Earth's total land area. The landmass contains well over 5 billion people, equating to approximately 70% of the human population. Humans first settled in Eurasia between 60,000 and 125,000 years ago. Some major islands, including Great Britain, Iceland, and Ireland, and those of Japan, the Philippines and Indonesia, are often included under the popular definition of Eurasia, in spite of being separate from the contiguous landmass.
Physiographically, Eurasia is a single continent. The concepts of Europe and Asia as distinct continents date back to antiquity and their borders are geologically arbitrary. In ancient times the Black Sea and the Sea of Marmara, along with their associated straits, were seen as separating the continents, but today the Ural and Caucasus ranges are more seen as the main delimiters between the two. Eurasia is connected to Africa at the Suez Canal, and Eurasia is sometimes combined with Africa to make the largest contiguous landmass on Earth called Afro-Eurasia. Due to the vast landmass and differences in latitude, Eurasia exhibits all types of climate under the Köppen classification, including the harshest types of hot and cold temperatures, high and low precipitation and various types of ecosystems.Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, Asia to the east, and the Mediterranean Sea to the south. It comprises the westernmost part of Eurasia.
Europe is most commonly considered to be separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas and the waterways of the Turkish Straits. Although the term "continent" implies physical geography, the land border is somewhat arbitrary and has been redefined several times since its first conception in classical antiquity. The division of Eurasia into two continents reflects East-West cultural, linguistic and ethnic differences which vary on a spectrum rather than with a sharp dividing line. The geographic border between Europe and Asia does not follow any state boundaries: Turkey, Russia, Azerbaijan, Georgia and Kazakhstan are transcontinental countries. France, Portugal, Netherlands, Spain and United Kingdom are also transcontinental in that the main portion is in Europe while pockets of their territory are located in other continents.
Europe covers about 10,180,000 square kilometres (3,930,000 sq mi), or 2% of the Earth's surface (6.8% of land area). Politically, Europe is divided into about fifty sovereign states of which the Russian Federation is the largest and most populous, spanning 39% of the continent and comprising 15% of its population. Europe had a total population of about 741 million (about 11% of the world population) as of 2016. The European climate is largely affected by warm Atlantic currents that temper winters and summers on much of the continent, even at latitudes along which the climate in Asia and North America is severe. Further from the sea, seasonal differences are more noticeable than close to the coast.
Europe, in particular ancient Greece and ancient Rome, was the birthplace of Western civilization. The fall of the Western Roman Empire in 476 AD and the subsequent Migration Period marked the end of ancient history and the beginning of the Middle Ages. Renaissance humanism, exploration, art and science led to the modern era. Since the Age of Discovery started by Portugal and Spain, Europe played a predominant role in global affairs. Between the 16th and 20th centuries, European powers controlled at various times the Americas, almost all of Africa and Oceania and the majority of Asia.
The Age of Enlightenment, the subsequent French Revolution and the Napoleonic Wars shaped the continent culturally, politically and economically from the end of the 17th century until the first half of the 19th century. The Industrial Revolution, which began in Great Britain at the end of the 18th century, gave rise to radical economic, cultural and social change in Western Europe and eventually the wider world. Both world wars took place for the most part in Europe, contributing to a decline in Western European dominance in world affairs by the mid-20th century as the Soviet Union and the United States took prominence. During the Cold War, Europe was divided along the Iron Curtain between NATO in the West and the Warsaw Pact in the East, until the revolutions of 1989 and fall of the Berlin Wall.
In 1949 the Council of Europe was founded, following a speech by Sir Winston Churchill, with the idea of unifying Europe to achieve common goals. It includes all European states except for Belarus, Kazakhstan and Vatican City. Further European integration by some states led to the formation of the European Union (EU), a separate political entity that lies between a confederation and a federation. The EU originated in Western Europe but has been expanding eastward since the fall of the Soviet Union in 1991. The currency of most countries of the European Union, the euro, is the most commonly used among Europeans; and the EU's Schengen Area abolishes border and immigration controls among most of its member states.Indian subcontinent
The Indian subcontinent is a southern region and peninsula of Asia, mostly situated on the Indian Plate and projecting southwards into the Indian Ocean from the Himalayas. Geologically, the Indian subcontinent is related to the land mass that rifted from Gondwana and merged with the Eurasian plate nearly 55 million years ago. Geographically, it is the peninsular region in south-central Asia delineated by the Himalayas in the north, the Hindu Kush in the west, and the Arakanese in the east. Politically, the Indian subcontinent includes Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka.Sometimes, the geographical term 'Indian subcontinent' is used interchangeably with 'South Asia', although that last term is used typically as a political term and is also used to include Afghanistan. Which countries should be included in either of these remains the subject of debate.Lemuria (continent)
Lemuria or Limuria is a hypothetical lost land located in either the Indian or the Pacific Ocean, as postulated by a now-discredited 19th-century scientific theory. The idea was then adopted by the occultists of the time and consequently has been incorporated into pop culture. Some Tamil writers have associated it with Kumari Kandam, a mythical lost continent with an ancient Tamil civilization located south of present-day India in the Indian Ocean.List of tallest buildings
This list of tallest buildings includes skyscrapers with continuously occupiable floors and a height of at least 350 m. Non-building structures, such as towers, are not included in this list (see list of tallest buildings and structures).
Historically, the world's tallest man-made structure was the Great Pyramids of Giza in Egypt, which held the position for over 3,800 years until the construction of the Lincoln Cathedral in England in 1311. Until the completion of the Washington Monument in 1884, the world's tallest buildings were churches and cathedrals, Christian places of worship, in Europe. The early skyscraper was pioneered in Chicago, forming the basis for which the United States would hold the position of the world's tallest building for much of the 20th century until 1998, when the Petronas Twin Towers were completed. Since then only two more buildings have held the title: Taipei 101 and Burj Khalifa.
Since the beginning of the 21st century, China, the Middle East as well as Southeast Asia have seen a boom in skyscraper construction.List of transcontinental countries
This is a list of countries located on more than one continent, known as transcontinental states or intercontinental states. While there are many countries with non-contiguous overseas territories fitting this definition, only a limited number of countries have territory straddling an overland continental boundary, most commonly the line that separates Europe and Asia.
The boundary between Europe and Asia is purely conventional, and several conventions remained in use well into the 20th century. However, the now-prevalent convention, used for the purposes of this list, follows the Caucasus northern chain, the Ural River and the Ural Mountains. It has been in use by some cartographers since about 1850. This convention results in several countries finding themselves almost entirely in "Asia", with a few small enclaves or districts technically in "Europe". Notwithstanding these anomalies, this list of transcontinental or intercontinental states respects the convention that Europe and Asia are full continents rather than subcontinents or component landmasses of the larger Eurasian continent.
Listed further below, separately, are countries with distant non-contiguous parts (overseas territories) on separate continents.New World
The New World is one of the names used for the majority of Earth's Western Hemisphere, specifically the Americas (including nearby islands), and Oceania.
The term originated in the early 16th century after Europeans made landfall in what would later be called the Americas in the Age of Discovery, expanding the geographical horizon of classical geographers, who had thought of the world as consisting of Africa, Europe, and Asia, collectively now referred to as the Old World (a.k.a. Afro-Eurasia).
The phrase gained prominence after the publication of a pamphlet titled Mundus Novus attributed to Italian explorer Amerigo Vespucci.The Americas were also referred to as the "fourth part of the world".North America
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.
North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the earth's land area and about 4.8% of its total surface.
North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands (most notably around the Caribbean) are included.
North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge approximately 40,000 to 17,000 years ago. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago (the beginning of the Archaic or Meso-Indian period). The Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended in 1492, with the beginning of the transatlantic migrations—the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples, African slaves and their descendants.
Owing to Europe's colonization of the Americas, most North Americans speak European languages such as English, Spanish or French, and their states' cultures commonly reflect Western traditions.South America
South America is a continent in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. It may also be considered a subcontinent of the Americas, which is how it is viewed in the Spanish and Portuguese-speaking regions of the Americas. The reference to South America instead of other regions (like Latin America or the Southern Cone) has increased in the last decades due to changing geopolitical dynamics (in particular, the rise of Brazil).It is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. It includes twelve sovereign states (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela), a part of France (French Guiana), and a non-sovereign area (the Falkland Islands, a British Overseas Territory though this is disputed by Argentina). In addition to this, the ABC islands of the Kingdom of the Netherlands, Trinidad and Tobago, and Panama may also be considered part of South America.
South America has an area of 17,840,000 square kilometers (6,890,000 sq mi). Its population as of 2016 has been estimated at more than 420 million. South America ranks fourth in area (after Asia, Africa, and North America) and fifth in population (after Asia, Africa, Europe, and North America). Brazil is by far the most populous South American country, with more than half of the continent's population, followed by Colombia, Argentina, Venezuela and Peru. In recent decades Brazil has also concentrated half of the region's GDP and has become a first regional power.Most of the population lives near the continent's western or eastern coasts while the interior and the far south are sparsely populated. The geography of western South America is dominated by the Andes mountains; in contrast, the eastern part contains both highland regions and vast lowlands where rivers such as the Amazon, Orinoco, and Paraná flow. Most of the continent lies in the tropics.
The continent's cultural and ethnic outlook has its origin with the interaction of indigenous peoples with European conquerors and immigrants and, more locally, with African slaves. Given a long history of colonialism, the overwhelming majority of South Americans speak Portuguese or Spanish, and societies and states reflect Western traditions.Zealandia
Zealandia (), also known as the New Zealand continent or Tasmantis, is an almost entirely submerged mass of continental crust that sank after breaking away from Australia 60–85 million years ago, having separated from Antarctica between 85 and 130 million years ago. It has variously been described as a continental fragment, a microcontinent, a submerged continent, and a continent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995. Zealandia's status as a continent is not universally accepted, but New Zealand geologist Nick Mortimer has commented that "if it wasn't for the ocean" it would have been recognized as such long ago.The land mass may have been completely submerged about 23 million years ago, and most of it (93%) remains submerged beneath the Pacific Ocean. With a total area of approximately 4,920,000 km2 (1,900,000 sq mi), it is the world's largest current microcontinent, more than twice the size of the next-largest microcontinent and more than half the size of the Australian continent. As such, and due to other geological considerations, such as crustal thickness and density, it is arguably a continent in its own right. This was the argument which made news in 2017, when geologists from New Zealand, New Caledonia, and Australia concluded that Zealandia fulfills all the requirements to be considered a continent, rather than a microcontinent or continental fragment.Zealandia supports substantial inshore fisheries and contains gas fields, of which the largest known is New Zealand's Maui gas field, near Taranaki. Permits for oil exploration in the Great South Basin were issued in 2007. Offshore mineral resources include iron sands, volcanic massive sulfides and ferromanganese nodule deposits.
Continents of the world