Continents and oceans on the surface of the earth. What is the mainland and what does it consist of

The mainland is called a significant land surface, which is washed from all sides by oceans or seas.

How many continents on Earth and their names

The earth is very big planet, but despite this, its significant area is water - more than 70%. And only about 30% is occupied by continents and islands of different sizes.

One of the largest is Eurasia, it occupies over 54 million square meters. It houses the 2 largest parts of the world - Europe and Asia. Eurasia is the only continent that is washed on all sides by oceans. On its shores you can see a large number of large and small bays, islands of different sizes. Eurasia is located on 6 tectonic platforms, which is why its relief is so diverse.

The highest mountains are located in Eurasia, as well as Baikal - the deepest lake. The population of this part of the world is almost a third of the entire planet, which live in 108 states.

Africa covers over 30 million square meters... The name of all continents on the planet is studied in detail in school curriculum, but some people in adulthood do not know their number. This may be due to the fact that continents are often called continents in geography lessons. These two names have significant differences. The main difference is that the continent has no land border.

Africa is the hottest among all the others. The main part of its surface is made up of plains and mountains. In hot Africa flows the longest river on Earth - the Nile, as well as the desert - the Sahara.

Africa is divided into 5 regions: South, North, West, East, and Central. 62 countries are located on this part of the Earth.

North America is included in the name of all continents.... It is washed on all sides by the Pacific, Arctic and Atlantic Ocean. The coast of North America is uneven, along with a large number of large and small bays, islands of different sizes, straits and bays. In the central part there is a huge plain.

North America

The local inhabitants of the mainland are Eskimos or Indians. In total, there are 23 states in this part of the Earth, among them: Mexico, USA and Canada.

South America occupies on the surface of the planet more than 17 million square meters. It is washed by the Pacific and Atlantic Oceans, and is also home to the longest mountain range. The rest of the surface is mainly plateaus or plains. Of all the parts, South America is the rainiest. Its indigenous inhabitants are Indians living in 12 states.

South America

The number of continents on planet Earth includes and Antarctica, its area is more than 14 million square meters. Its entire surface is covered with blocks of ice, the average thickness of this layer is about 1500 meters. Scientists have calculated that if this ice melted completely, the water level on Earth would rise by about 60 meters!

Antarctica

Its main area is a desert of ice, the population lives only on the shores. Antarctica is the lowest-temperature surface of the planet, the average air temperature is from -20 to -90 degrees.

Australia- the occupied area is more than 7 million square meters. It is the only continent with only 1 state. Plains and mountains occupy its main area, they are located along the entire coast. It is in Australia that the largest number of large and small wild animals and birds live, and there is also the greatest variety of vegetation. The indigenous people are Aborigines and Bushmen.

Australia

How many continents on Earth are 6 or 7?

There is an opinion that their number is not 6 at all, but 7. The area around the South Pole is huge blocks of ice. Currently, many scientists call it another continent on planet Earth. But there is no life at this South Pole, only penguins live.

To the question: “ How many continents are there on planet Earth?", You can answer exactly - 6.

Continents

There are only 4 continents on Earth:

1. America.
2. Antarctica.
3. Australia.
4. AfroEurasia.

But each country has its own opinion about their number. For example, in India, as well as the inhabitants of China, they believe that their total number is 7, the inhabitants of these countries call Asia and Europe separate continents. The Spaniards, when they mention continents, name all surfaces of the world associated with America. And the inhabitants of Greece say that there are only 5 continents on the planet, because as soon as people live on them.

What is the difference between the island and the mainland

And then, and another definition - this is a large or smaller area of ​​land, washed on all sides by water. At the same time, there are certain significant differences between them.

1. Dimensions. One of the smallest is Australia, it occupies a much larger area than Greenland - one of the largest islands.
2. History of education. Each island is formed in a special way. There are continents that arose as a result of ancient fragments of the plates of the lithosphere. Others are due to volcanic eruptions. There are also those species that emerged from polyps, they are also called "coral islands".
3. Its habitability. There is life on absolutely all six continents, even on the coldest one - Antarctica. But most of the islands remain uninhabited to this day. But on them you can meet animals and birds of a wide variety of breeds, see plants that have not yet been explored by man.

MAINLAND
or a continent, a large land mass (as opposed to a smaller massif - an island), surrounded by water. There are seven parts of the world (Europe, Asia, Africa, North America, South America, Australia and Antarctica) and six continents: Eurasia, Africa, North America, South America, Australia and Antarctica. Some large islands are similar in size to the mainland and are sometimes referred to as "mainland islands". Among them, the most famous are Greenland, New Guinea, Kalimantan and Madagascar. The continents are surrounded by shallow oceans - shelves, with depths usually not exceeding 150 m.

MATERIALS AND THEIR DIMENSIONS

The names of parts of the world and continents have different origins. The ancient Greeks called all the lands west of the Bosphorus Europe, and to the east of it Asia. The Romans divided their eastern (Asian) provinces into Asia and Asia Minor (Anatolia). The name "Africa", also of ancient origin, referred only to the northwestern part of the continent and did not include Egypt, Libya and Ethiopia. Ancient geographers assumed that there should be a large continent in the south (Terra Australis - southern land) that would counterbalance the vast land masses in the north, but it was not discovered until the 17th century. Its original name " New Holland"later it was replaced by" Australia. "The first guesses about the existence of Antarctica (which means" the antipode of the Arctic ") date back to the 18th century, but the discovery and exploration of this continent refers only to the 19th and 20th centuries. In contrast to Australia, the existence of America is not was predicted, and when it was discovered, it was mistaken for part of China or India.The term "America" ​​first appeared on the map of Martin Waldseemüller (1507), who so named the New World in honor of the geographer and explorer Amerigo Vespucci. Vespucci was probably the first to understand that a new continent was discovered.The very term "mainland" in its modern meaning appeared in England in the 17th century. The continents account for 94% of the land area and 29% of the planet's surface area. However, not all of the continent is land, since there are large inland seas (for example, the Caspian), lakes and areas covered with ice (especially in Antarctica and Greenland). The boundaries of the continents have often been the subject of controversy. The inhabitants of the UK, for example, traditionally from divided their island state from the mainland of Europe, which, in their opinion, began from Calais. The borders of parts of the world and continents have always caused "headaches" to geographers. Europe and Asia are delineated along the watershed Ural mountains, but to the south, the border becomes less clear and is again defined only in the Greater Caucasus. Further, the border runs along the Bosphorus, dividing Turkey into the European part (Thrace) and the Asian part (Anatolia, or Asia Minor). A similar problem arises in Egypt: the Sinai Peninsula is often referred to as Asia. From a geographical point of view, the whole of Central America, including Panama, is usually annexed to North America, but politically, it is often practiced to assign all territories located south of the USA, to Latin America.
STRUCTURAL GEOLOGY
The word "continent" comes from the Latin continens (continere - to stick together), which implies structural unity, although not necessarily in relation to land. With the development of the theory of tectonics of lithospheric plates in geology, a geophysical definition of continental plates arose in contrast to oceanic ones. These structural units have completely different structure, power and development history. The continental crust, consisting of rocks, which mainly include silicon (Si) and aluminum (Al), is lighter and much older (some areas are more than 4 billion years old) than the oceanic crust, which consists mainly of silicon (Si) and magnesium (Mg) and having an age of no more than 200 million years. The boundary between the continental and oceanic crust runs along the foot of the continental slope or along the outer edge of the shallow shelf that borders each continent. The shelf adds 18% to the area of ​​the continents. This geophysical definition emphasizes the well-known differences between such "mainland islands" as British, Newfoundland and Madagascar, from oceanic ones - Bermuda, Hawaiian and Guam.
History of the continents. In the course of a long evolution crust continents gradually expanded due to the accumulation of lava and ash during volcanic eruptions, the intrusion of molten magma from rocks such as granite, and the accumulation of sediments originally deposited in the ocean. The constant fragmentation of ancient land masses - "foremothers" - predetermined the drift of the continents, as a result of which they periodically collided. Ancient mainland slabs were firmly connected along these contact lines, or "seams", forming a complex mosaic ("patchwork quilt") structural units that make up modern continents. In eastern North America, such a suture zone can be traced from Newfoundland to Alabama. The fossils found in the rocks to the east of it are of African origin, which is evidence of the separation of this area from the African continent (about 300 million years ago). Another suture zone, marking the collision of Europe with Africa about 100 million years ago, is traced in the Alps. Another seam runs along the southern border of Tibet, where the Indian subcontinent collided with the Asian one and in geologically recent time (about 50 million years ago) the Himalayan mountain system was formed.

The theory of plate tectonics is today as common in geology as, for example, the law of gravity in physics. Rocks and fossils of the "African type" are found in many places in the east of America. Suture zones can be clearly seen on satellite images. It is possible to measure the speeds of upward movements where the mountains, which have arisen as a result of the collision of continents, still continue to rise. These speeds do not exceed 1 mm per year in the Alps, and in some parts of the Himalayas are more than 10 mm per year. The logical consequence of the considered mechanism of mountain building is continental rifting and ocean floor spreading. Fragmentation of the earth's crust is a widespread phenomenon, clearly visible on satellite images. Major fault lines, called lineaments, can be traced both in space - thousands of kilometers, and in time - to the most ancient stages of geological history. When both sides of the lineament are strongly displaced, a fault is formed. The origin of the largest faults has not yet been fully established. The computer model of the network of faults suggests that their formation is associated with changes in the shape of the globe in the past, which, in turn, was predetermined by fluctuations in the speed of rotation of the Earth and a change in the position of its poles. These changes were caused by a number of processes, among which the most significant influence was exerted by ancient glaciations and the bombardment of the Earth by meteorites. Ice ages recurred approximately every 250 million years and were accompanied by the accumulation of significant masses of glacial ice near the poles. This accumulation of ice caused an increase in the speed of the Earth's rotation, leading to a flattening of its shape. At the same time, the equatorial belt expanded in diameter, and the spheroid seemed to contract at the poles (that is, the Earth became less and less like a ball). Due to the fragility of the earth's crust, a network of intersecting faults has formed. The Earth's rotation rate changed dozens of times during one ice age. In the early stages of Earth's history, there was an intense bombardment of the planet by asteroids and smaller objects - meteorites. It was uneven and, apparently, led to a deviation of the axis of rotation and a change in its speed. The scars from these impacts and the craters left by the "heavenly guests" are visible everywhere on the lower planets (Mercury and Venus), although the earth's surface they are partially masked by precipitation, water and ice. These bombings also contributed to the chemical composition of the mainland crust. Since the falling objects tended to concentrate near the equator, they increased the mass of the outer edge of the globe, noticeably slowing down the speed of its rotation. In addition, throughout geological history, any powerful outpouring of volcanic lavas in one of the hemispheres or any movement of masses contributed to a change in the inclination of the axis of rotation and the speed of rotation of the Earth. It was found that lineaments are weakened zones of the continental crust. The earth's crust is able to bend like a window pane under the onslaught of gusts of wind. All of it is actually cut by faults. Along these zones, minor movements occur all the time, due to the tidal forces of the moon. As the plate moves towards the equator, it is subjected to more and more stress, both due to the action of tidal forces and due to changes in the speed of rotation of the Earth. These stresses are most pronounced in the central parts of the continents, where rifting occurs. Zones of young rifting occur in North America from the Snake River to the Rio Grande River, in Africa and the Middle East - from the Jordan River Valley to Lakes Tanganyika and Nyasa (Malawi). IN central regions Asia also has a rift system passing through Lake Baikal. As a result of long-term processes of rifting, continental drift and their collisions, the continental crust was formed in the form of a "patchwork quilt", consisting of fragments of different ages. It is curious to note that at the present time, apparently, rocks of all geological eras are represented on each continent. The basis of the continents is made up of the so-called. shields, composed of ancient solid crystalline rocks (mainly of granite and metamorphic series), which belong to different epochs of the Precambrian (i.e., their age exceeds 560 million years). In North America, such an ancient core is the Canadian Shield. At least 75% of the continental crust was formed 2.5 billion years ago. Areas of shields covered by sedimentary rocks are called platforms. They are characterized by flat flat relief or gently undulating arched uplands and hollows. When drilling for oil, the crystalline basement is sometimes exposed under sedimentary rocks. Platforms are always extensions of ancient shields. In general, this core of the continent - the shield together with the platform - is called the craton (from the Greek krtos - strength, fortress). Fragments of young folded mountain belts, usually including small cores ("fragments") of other continents, are attached to the edges of the craton. Thus, in North America, in the eastern Appalachians, there are "fragments" of African origin. These young components of each continent provide clues to the history of the ancient shield and, apparently, evolved in much the same way as itself. In the past, the shield also consisted of mountain belts, which are now leveled almost to a flat or only moderately dissected by erosion of the relief. Such a leveled surface, called a peneplain, is the result of erosion-denudation processes that took place more than half a billion years ago. Basically, these alignment processes took place under tropical crust formation conditions. Since the main agent of such processes is chemical weathering, a sculptural plain is formed as a result. In the modern era, only bedrocks are represented on the shields, which remained after rivers and glaciers destroyed and demolished ancient loose sediments. In younger mountain belts, uplifts were often repeated along the edges of the cratons, but there was not enough time for the formation of the peneplain, so a series of stepped erosional surfaces formed instead.
Continental rifting. The most impressive result of young rifting is the Red Sea rift between the Arabian Peninsula and Northeast Africa. The formation of this rift began ca. 30 million years ago and continues to this day. The opening of the Red Sea depression continues to the south in the East African rift zone and to the north - in the Dead Sea zone and the Jordan River valley. The biblical story of the collapsed walls of Jericho is probably based on fact, since this ancient city is within the main drop zone. The Red Sea is a "young ocean". Although its width is only 100-160 km, the depths in some areas are comparable to those in the ocean, but what is most remarkable is that there are no remnants of the continental crust there. Previously, it was believed that the rift is like a destroyed arch with a fallen upper ("castle") stone. Numerous studies have not confirmed this assumption. It has been established that the two edges of the rift are, as it were, moved apart, and the bottom consists of hardened "oceanic" lava, currently largely overlapped by young sediments. This is the beginning of seafloor spreading, a geological process that produces ocean-type crust (ocean floor spreading is seen as strong evidence in favor of plate tectonics theory.) All deep oceans have this type of crust, and only shallow seas like the Hudson or Persian Gulfs. are underlain by the continental crust. At the beginning of the formation of plate tectonics theory, the question was often asked: if continental rifts and ocean floors expand during spreading, should not the globe itself expand accordingly? The mystery was solved when subduction zones were discovered - planes tilted at approximately 45 °, along which the oceanic crust is pushed under the edge of the continental plate. At a depth of approx. 500-800 km from the Earth's surface, the crust melts and rises again, forming magma chambers - reservoirs with lava, which then erupts from volcanoes.
Volcanoes. The locations of volcanoes are closely related to the movement of lithospheric plates, with three types of volcanic zones being distinguished. The volcanoes of the subduction zones form the Pacific "ring of fire", the Indonesian arc and the Antillean arc in the West Indies. Such volcanoes of subduction zones are known as Fujiyama in Japan, St. Helens and others in the Cascade Mountains of the USA, Montagne Pele in the West Indies. Inland volcanoes are often associated with fault zones or rifts. They are found in the Rocky Mountains from Yellowstone National Park and the Snake River to the Rio Grande River, as well as in East Africa(e.g. Mount Kenya and Mount Kilimanjaro). Volcanoes of mid-oceanic fault zones are found on the oceanic islands of Hawaii, Tahiti, Iceland, etc. Both inland and mid-oceanic volcanoes (at least the largest of them) are associated with deep-lying "hot spots" (ascending convective jets) in the mantle. As the overlapping plate moves, a chain of volcanic centers appears, arranged in chronological order. These three types of volcanoes differ in the nature of their volcanic activity, chemical composition lava and development history. Only the lava of volcanoes in subduction zones contains large volumes of dissolved gases, which can lead to catastrophic explosions. Other types of volcanoes can hardly be called "friendly", but they are much less dangerous. Note that only the most general classification of eruptions is possible, since the activity of the same volcano each time proceeds in its own way, and even separate phases of one eruption may differ.
The surface of the continents. The features of the relief of the continents are studied by the science of geomorphology (geo is a derivative of the Greek goddess of the Earth Gaia, morphology is the science of forms). Landforms can be of any size: from large, including mountain systems (such as the Himalayas), giant river basins (Amazon), deserts (Sahara); to small ones - sea beaches, cliffs, hills, streams, etc. Each relief form can be analyzed from the point of view of structural features, material composition and development. It is also possible to consider dynamic processes, which are understood as physical mechanisms that caused the change in relief forms in time, i.e. predetermined the modern appearance of the relief. Almost all geomorphological processes depend on the following factors: the nature of the source material (substrate), the structural position and tectonic activity, as well as the climate. The largest landforms are mountain systems, plateaus, depressions and plains. Mountain systems have undergone crushing and compression in the process of plate movement; at present, erosion-denudation processes prevail there. The land surface is gradually destroyed by frost, ice, rivers, landslides and wind, and the products of destruction accumulate in depressions and plains. Structurally, mountains and plateaus are characterized by continuing uplifts (from the point of view of the theory of plate tectonics, this means heating of deep layers), while depressions and plains are characterized by weak subsidence (due to cooling of deep layers).

There is a compensation process, the so-called. isostasy, one of the results of which is that as the mountains are destroyed by erosion, they experience an uplift, and on the plains and depressions where sediment accumulates, there is a tendency to sink. The asthenosphere is located under the earth's crust, consisting of molten rocks, on the surface of which they "float" lithospheric plates ... If any part of the earth's crust is overloaded, then it will "sink" (sink into molten rock), while the rest of it will "float" (rise). The main reason for the uplifting of mountains and plateaus is plate tectonics, however, erosion-denudation processes in combination with isostasy contribute to the periodic rejuvenation of ancient mountain systems. Plateaus are similar to mountains, but they are not crushed as a result of collision (collision of plates), but are raised as a single block and are usually characterized by horizontal bedding of sedimentary rocks (which, for example, is clearly visible in the outcrops of the Grand Canyon in Colorado). Another geological process that plays a very important role in the long history of the continents - eustasia - reflects global fluctuations in sea level. There are three types of eustasia. Tectonic eustasia is caused by changes in the shape of the seabed. During rapid subduction, the width of the oceanic basin shrinks and the sea level rises. The oceanic basin also becomes shallower due to thermal expansion of the oceanic crust with a sudden acceleration of the spreading of the seabed. Sedimentary eustasia is caused by the filling of the oceanic basin with sediments and lava. Glacioeustasia is associated with the removal of water from the oceans during continental glaciations and its return during the subsequent global melting of glaciers. During periods of maximum glaciation, the area of ​​the continents increased by almost 18%. Of the three considered types, glacioeustasia has played the most important role in the history of mankind. On the other hand, the effect of tectonic eustasia was the longest. Periodically, the level of the World Ocean rose, and as a result, significant parts of the continents were flooded. The exceptions were mountains. These global floods are called "thalassocratic" (from the Greek thlassa sea and krtos - strength, power) phases of the Earth's development. The last such flood occurred ca. 100 million years ago, in the era of dinosaurs (some living organisms of that time preferred an aquatic lifestyle). The marine sediments of that time, with their characteristic fossils, found in the inland regions, indicate that North America, from the Gulf of Mexico to the Arctic, was submerged by the sea. Africa was divided into two parts by a shallow strait crossing the Sahara. Thus, each continent shrank to the size of a large archipelago. Quite different conditions existed in the era when the ocean floor was sinking. The sea retreated from the shelves, and the land expanded everywhere. Such epochs are called "epeirocratic" (from the Greek. peiros - mainland, land). The alternation of epeirocratic and thalassocratic phases determined the main course of geological history and left traces in the main features of the relief of each continent. These phenomena also had a great impact on the flora and fauna. The course of evolution, both physical and biological world was also determined by changes in the area of ​​the oceans. During the thalassocratic phases, an oceanic climate was formed with moisture-saturated air masses penetrating the land. As a result, the average temperature on Earth was at least 5.5 ° C higher than today. Glaciers only existed in very high mountains... Conditions on all continents were more or less uniform, the land was covered with lush vegetation, which contributed to the development of soils. However, terrestrial animals experienced severe stress due to overpopulation and disunity, unlike their marine counterparts, which thrived on the vast expanses of vastly expanded shelves. During the epeirocratic phases, the opposite situation developed. The area of ​​the continents increased, and new habitats were ideal for the existence of large animals such as dinosaurs. The largest land area was approx. 200 million years ago, which favored the evolution of these creatures. In the climatic conditions of that time with a high "index of continentality", deserts and red-colored deposits were widespread, and mechanical erosion prevailed. The modern topography is closely related to the geological history. The appearance of the Alps or Himalayas testifies to a young uplift: these mountains are typical collisional structures. The Great Inland Plains of North America and northern Eurasia are overlain by predominantly subhorizontal sedimentary formations that were formed during repeated global marine transgressions throughout geological history. In turn, they are covered by a thin moraine cover (sediments of ice ages) and loess (products of the activity of especially strong winds, usually blowing in the direction from large ice sheets to their periphery). It is interesting to note that the plains of the Northern and Southern Hemispheres look completely different. In Brazil, South Africa and Australia, exotic landforms are invariably amazed. The modern era is an epeirocratic phase in the history of the Earth with the growing differentiation of individual continents and intensifying climatic contrasts. But why is there a difference between the northern and southern continents? The answer to this question is provided by plate tectonics. All northern continents have been moved apart for considerable distances and during the last almost 200 million years have been slowly moving northward. As a result of this drift, they moved from tropical and subtropical latitudes to temperate and arctic. Red-colored soils, typical for hot dry climates, were inherited from those distant times, and many existing landforms could not have formed in modern climatic conditions. In the recent geological past, vast areas of these continents were covered with glaciers. History of development southern continents was completely different. They experienced the last glaciation 250 million years ago, being part of the pre-existing ancestral land of Gondwana. Since then, they have gradually shifted northward (i.e. towards the modern equator), so that many modern forms relief in these regions inherited from colder climatic conditions... In the Northern Hemisphere, the land area is 48% larger than in the Southern. This distribution has a profound effect on the climate, causing a large continentality in the north and a large oceanicity in the south.
The rate of erosion-denudation processes. Studies have shown that in many regions of the world there are ancient land areas - cratons, which are outliers composed of ancient sedimentary formations, which are often cemented with a bed of silica and form solid, like quartz, covers. This cementation took place during the formation of sculpted plains in tropical and subtropical conditions. Once formed, such a carapace, armor-plating, could then exist unchanged for millions of years. In mountainous regions, rivers cut through this solid cover, but fragments of it often remain. Subhorizontal watersheds in the Appalachian, Ardennes and Urals represent the remnants of pre-existing sculpted plains. By the age of such ancient residual formations, the average speed denudation over a long time interval, amounting to approx. 10 cm in a million years. The surfaces of the ancient cratons of the Earth have absolute heights of 250-300 m, therefore, in order to cut them down to modern level sea, it would take approx. 3 billion years.
LITERATURE
Le Pichon C., Fransteau J., Bonnin J. Plate tectonics. M., 1977 Leontiev O.K., Rychagov G.I. General geomorphology. M., 1979 Ushakov S. A., Yasamanov N. A. Drift of continents and climates of the Earth. M., 1984 Khain V.E., Mikhailov A.E. General geotectonics. M., 1985

Collier's Encyclopedia. - Open Society. 2000 .

Today, with your permission, I will take a walk into the past and try to look a little into the future. What will be the object of my curiosity, who or what will become the hero of my story today? And it will become, literally, the land on which we live. No, reader, we are not talking about the planet - today I will tell my story about continents and continents.

What is the mainland

Mainland- he is continent(synonyms utterly are equivalent, just geologists prefer the first term, and politicians, for some reason, the second) - this is a large part of the earth's land, the edges of which, like a crust on a pie, bent, lowered down and are below ocean level... Why, you ask, Greenland is not considered a mainland, but Australia, for example, consider? It's simple. Greenland is made up of rocks from the oceanic crust, which is typical for islands, besides, he has no continental shelf... the same is "Piece" of continental crust, which, in addition to itself, includes the adjacent islands. So the most that Greenland "shines" is an encouraging "mainland island", although this title is somewhat unscientific.

Continental history

What is the mainland- sort of figured out. Now he will rewind the film a little, only for several billion years ago, and look at landform planet earth. Let me remind you - I deliberately do not dwell on modern continental models, I am more attracted to their history! So, how, according to numerous hypotheses of scientists, before the land and the ocean were more clearly separated than now, and all modern continents consisted of one- the so-called supercontinent:

• Kenorland, 2.75 billion years ago. The supercontinent was located in the southern latitudes.
• Nuna, 1.8 billion years ago. Consisted of the ancient "progenitors" of the Ukrainian shield, the Amazon, Australia, Siberia, the Kalahari platform and others.
• Lavrussia(Euroamerica, Caledonia, "Red continent"). It was formed as a result of the collision of the North American (Laurentian continent) and East European (Baltic continent) platforms, then merged with Pangea, becoming part of Laurasia.
• Gondwana, 700 million years ago, located around the South Pole. About 360 million years ago, it merged with the Scandinavian mainland in Pangea. About 80 million years ago, it split into modern continents.
• Pangea, Paleozoic. At the end of the Triassic period, it split into Laurasia and Gondwana.
• Laurasia, Mesozoic. Contained the modern northern continents.

The future of the continents

Some scientists agree in their forecast that through 100-200 million years old continents again come together in a large pile with the prefix "super". Suggest three options views of the future supercontinent:

• Pangea Ultima, a giant desert supercontinent dotted with towering mountain ranges;
• Amazia, a supercontinent centered at the North Pole, which is formed as a result of a sort of compression, "shrinking" of all modern continents together (as if a giant sponge was squeezed;
• Novopangea, with the Pacific Ocean closed inside the Australian-Asian chain and the extremely warmed Antarctica.

Each of us has heard the word "mainland". It is often used in educational institutions, news, movies, and even conversations with friends or colleagues. But not everyone can give precise definition the word "mainland" and tell about its features. So let's learn together about what the continent is and what is its role in our world.

What is the mainland: definition

The mainland (continent) is a fairly large massif of the earth's crust, the largest part of which protrudes above the surface of the World Ocean. From which we can conclude that the continent is not only land, but also its part located under water (peripheral).

In the modern era, there are six continents: South America, North America, Eurasia, Australia, Africa, and Antarctica. The largest of these is Eurasia. It is located in all four hemispheres and occupies more than a third of the land area of ​​our huge planet.

What does continental geography study? Continental geography studies the natural landscapes of the earth's surface, planetary patterns, as well as the conditions for their emergence, distribution and development. When studying the geography of the continents huge role playing use geographic maps which are subdivided into groups. For example, to study the geography of the continents, you need to familiarize yourself with the 3 main groups of maps: by the topic they are devoted to, by the coverage of the territory and by scale. In addition to maps, it is important to study aerial photographs and space images from satellites. To study the geography of continents, there are several research methods: cartographic, historical, observation method, physical, mathematical, chemical methods, as well as the method of space research.

Continent(from Latin continens, genitive continentis) - a large massif of the earth's crust, a significant part of which is located above sea level (land), and the rest of the peripheral part is below sea level. The continent also includes islands located on the underwater periphery. In addition to the concept of continent, the term continent is also used.

Terminology

Mainland- a vast expanse of land, washed by seas and oceans (or Land, land - as opposed to water or islands). In Russian, the words continent and continent have the same meaning.

From a tectonic point of view, continents are areas of the lithosphere with a continental structure of the earth's crust.

There are several continental models in the world (see below). On the territory of the post-Soviet space, the model of six continents with a divided America is adopted as the main one.

There is also a similar concept of a part of the world. The division into continents is carried out on the basis of separation by water space, and parts of the world are more of a historical and cultural concept. Thus, the continent of Eurasia consists of two parts of the world - Europe and Asia. And part of the world America is located on two continents - South America and North America. In other cases, parts of the world coincide with the above continents.

The border between Europe and Asia runs along the Ural Mountains, then the Ural River to the Caspian Sea, the Kuma and Manych rivers to the mouth of the Don River and further along the shores of the Black and Mediterranean Seas. The Europe-Asia border described above is not indisputable. This is just one of several options accepted in the world.

In geology, the continent is also often referred to as the underwater margin of the continent, including the islands located on it.

In English and some other languages, continent refers to both continents and parts of the world.

Continental models

In the world different countries the number of continents is estimated differently. Number of continents in different traditions

• 4 continents: Afro-Eurasia, America, Antarctica, Australia
• 5 continents: Africa, Eurasia, America, Antarctica, Australia
• 6 continents: Africa, Europe, Asia, America, Antarctica, Australia
• 6 continents: Africa, Eurasia, North America, South America, Antarctica, Australia
• 7 continents: Africa, Europe, Asia, North America, South America, Antarctica, Australia

The seven continents model is popular in China, India, partly in Western Europe and in English-speaking countries.

The model of six continents with a united America (we usually call it "Parts of the World") is popular in Spanish-speaking countries and parts of eastern Europe, including Greece with its five-continent model (five inhabited continents).

Comparison of area and population

Continent	Length (km from east to west, and from south to north, along the periphery)	Share of sushi	Population	Population share
Afroeurasia
Oceania

- the largest and only continent on Earth, washed by four oceans: in the south - the Indian, in the north - the Arctic, in the west - the Atlantic, in the east - the Pacific. The continent is located in the Northern Hemisphere between approximately 9 ° W. d. and 169 ° W while part of the islands of Eurasia are located in the Southern Hemisphere. Most of continental Eurasia lies in the Eastern Hemisphere, although the extreme western and eastern ends of the continent are in the Western Hemisphere. Eurasia stretches from west to east for 10.5 thousand km, from north to south - for 5.3 thousand km, with an area of ​​53.6 million km2. This is more than a third of the entire land area of ​​the planet. The area of ​​the islands of Eurasia is approaching 2.75 million km2.

Contains two parts of the world: Europe and Asia. The border line between Europe and Asia is most often drawn along the eastern slopes of the Ural Mountains, the Ural River, the Emba River, the northwestern coast of the Caspian Sea, the Kuma River, the Kumo-Manych depression, the Manych River, the eastern coast of the Black Sea, the southern coast of the Black Sea, the strait The Bosphorus, the Sea of ​​Marmara, the Dardanelles, the Aegean and Mediterranean seas, the Strait of Gibraltar. This division has developed historically. Naturally, there is no sharp border between Europe and Asia. The continent is united by the continuity of the land, the currently formed tectonic consolidation and the unity of numerous climatic processes.

(English North America, French Amérique du Nord, Spanish América del Norte, Norteamérica, Ast. Ixachitlān Mictlāmpa) is one of the continents of planet Earth, located in the north of the Western Hemisphere of the Earth. North America is washed from the west by the Pacific Ocean with the Bering Sea, the Gulfs of Alaska and California, from the east by the Atlantic Ocean with the Labrador, Caribbean, Gulf of St. Lawrence and Mexico, and from the north by the Arctic Ocean with the Beaufort, Baffin, Greenland and Hudson Seas. From the west, the continent is separated from Eurasia by the Bering Strait. In the south, the border between North and South America runs across the Isthmus of Panama.

Numerous islands are also included in North America: Greenland, the Canadian Arctic Archipelago, the Aleutian Islands, Vancouver Island, the Alexander Archipelago and others. The area of ​​North America with islands is 24.25 million km2, without islands 20.36 million km2.

(Spanish América del Sur, Sudamérica, Suramérica, port América do Sul, English South America, Dutch Zuid-Amerika, French Amérique du Sud, guar Ñembyamérika, Quechua Urin Awya Yala, Urin Amerika in) - southern continent America, located mainly in the Western and Southern Hemispheres of the planet Earth, however, part of the continent is located in the Northern Hemisphere. It is washed in the west by the Pacific Ocean, in the east - by the Atlantic Ocean, from the north it is limited to North America, the border between the Americas runs along the Isthmus of Panama and the Caribbean Sea.

South America also includes various islands, most of which belong to the countries of the continent. The Caribbean territories belong to North America. The countries of South America that border the Caribbean - including Colombia, Venezuela, Guyana, Suriname, and French Guiana - are known as Caribbean South America.

The most important river systems in South America are the Amazon, Orinoco and Parana, with a combined basin of 7,000,000 km2 (South America area 17,800,000 km2). Most of the lakes in South America are located in the Andes, the largest of which and the world's highest navigable lake is Titicaca, on the border of Bolivia and Peru. The largest in area is Lake Maracaibo in Venezuela, it is also one of the oldest on the planet.

In South America, there is the highest waterfall in the world - Angel. The most powerful waterfall, Iguazu, is also located on the mainland.

- the second largest continent on our planet Earth after Eurasia, washed by the Mediterranean Sea from the north, the Red Sea from the northeast, the Atlantic Ocean from the west and the Indian Ocean from the east and south.

Africa is also called the part of the world, consisting of the continent of Africa and adjacent islands, the largest of which is the island of Madagascar.

The African continent is crossed by the equator and several climatic zones; its peculiarity is that it is the only continent stretching from the northern subtropical climatic zone to the southern subtropical.

Due to the lack of constant rainfall and irrigation on the denser continent - as well as glaciers or the aquifer of mountain systems - there is practically no natural regulation of the climate anywhere except on the coasts.

(from Latin austrālis - "southern") - a continent located in the Eastern and Southern hemispheres of our planet Earth.

The entire territory of the mainland is the main part of the state of the Commonwealth of Australia. The mainland is part of the world Australia and Oceania.

The northern and eastern coasts of Australia are washed by the seas of the Pacific Ocean: the Arafur, Coral, Tasman, Timor seas; western and southern - Indian Ocean.

The large islands of New Guinea and Tasmania are located near Australia.

Along the northeastern coast of Australia for more than 2000 km stretches the well-known, the world's largest coral reef - the Great Barrier Reef.

(Greek ἀνταρκτικός - the opposite of Arctida) - a continent located in the very south of the Earth, the center of Antarctica roughly coincides with the southern geographic pole... Antarctica is washed by the waters of the Southern Ocean. Antarctica is also called the part of the world, consisting of the mainland of Antarctica and adjacent islands.

Antarctica is the highest continent, its average height is 2040 meters. The mainland also contains about 85% of the planet's glaciers. There is no permanent population on Antarctica, but there are more than forty scientific stations belonging to different states and intended for research and detailed study of the characteristics of the continent.

Antarctica is almost completely covered with ice sheets, the average thickness of which is more than 2500 meters. There are also a large number of subglacial lakes (over 140), the largest of which is Lake Vostok, discovered by Russian scientists in the 1990s.

Hypothetical continents

Kenorland

Kenorland is a hypothetical supercontinent, which, according to geophysicists, existed in the Neoarchean (about 2.75 billion years ago). The name comes from the Kenoran folding phase. Paleomagnetic studies indicate that Kenorland was at low latitudes.

Nuna

Nuna (Columbia, Hudsonland) is a hypothetical supercontinent that existed between 1.8 and 1.5 billion years ago (maximum assembly ~ 1.8 billion years ago). Its existence was suggested by J. Rogers and M. Santosh in 2002. Nuna dates back to the Paleoproterozoic era, making it supposedly the oldest supercontinent. It consisted of the precursor plateaus of the ancient platforms that were part of the earlier continents of Laurentia, Fennosarmatia, the Ukrainian Shield, the Amazon, Australia and possibly Siberia, the Sino-Korean platform and the Kalahari platform. The existence of the continent of Columbia is based on geological and paleomagnetic data.

Rodinia

Rodinia (from Russian Motherland or from Russian to give birth) is a hypothetical supercontinent, presumably existing in the Proterozoic - Precambrian eon. It originated about 1.1 billion years ago and disintegrated about 750 million years ago. At that time, the Earth consisted of one giant piece of land and one giant ocean, called Mirovia, also taken from the Russian language. Rodinia is often considered the oldest known supercontinent, but its position and shape are still the subject of controversy. After the collapse of Rodinia, the continents managed to once again unite into the supercontinent Pangea and disintegrate again.

Lavrussia

Lavrusia (Euramerica) is a Paleozoic supercontinent formed as a result of the collision of the North American (ancient continent of Laurentia) and East European (ancient continent of the Baltic Sea) platforms during the Caledonian orogeny. The names of Caledonia, "Old Red Continent", "Old Red Sandstone Continent" are also known. In the Permian period, it merged with Pangea and became its integral part. After the collapse of Pangea, it became part of Laurasia. In the Paleogene it disintegrated.

Gondwana

Gondwana in paleogeography is an ancient supercontinent that arose about 750-530 million years ago, for a long time localized around the South Pole, which included almost the entire land, now located in the southern hemisphere (Africa, South America, Antarctica, Australia), as well as tectonic blocks of Hindustan and Arabia, which have now moved to the northern hemisphere and became part of the Eurasian continent. In the early Paleozoic, Gondwana gradually shifted northward and in the Carboniferous period (360 million years ago) merged with the North American-Scandinavian continent into the giant protocontinent Pangea. Then, during the Jurassic period (about 180 million years ago), Pangea again split into Gondwana and the northern continent of Laurasia, which were divided by the Tethys Ocean. 30 million years later, in the same Jurassic period, Gondwana gradually began to disintegrate into new (present) continents. Finally, all modern continents: Africa, South America, Australia, Antarctica and the Indian subcontinent separated from Gondwana only at the end of the Cretaceous period, that is, 70-80 million years ago.

Pangea

Pangea (ancient Greek Πανγαῖα - "all-earth") is the name given by Alfred Wegener to the proto-continent that arose in the Paleozoic era. The giant ocean that washed Pangea from the Silurian period of the Paleozoic to the Early Mesozoic, inclusive, was named Panthalassa (from ancient Greek παν- “all-” and θάλασσα “sea”). Pangea was formed in the Permian period, and split at the end of the Triassic (about 200 - 210 million years ago) into two continents: the northern continent - Laurasia and the southern continent - Gondwana. In the process of the formation of Pangea, mountain systems arose from the more ancient continents at the places of their collision, some of them have existed to this day, for example, the Urals or the Appalachians. These early mountains are much older than the relatively young mountain systems (the Alps in Europe, the Cordillera in North America, the Andes in South America, or the Himalayas in Asia). Due to erosion lasting for many millions of years, the Urals and Appalachians are low-rolling mountains.

Kazakhstan

Kazakhstan is a Middle Paleozoic continent located between Lavrusia and the Siberian platform. It stretches from the Turgai trough and the Turan lowland to the Gobi and Taklamakan deserts.

Laurasia

Laurasia is a supercontinent that existed as the northern part of the Pangea protocontinent (southern - Gondwana) fault in the Late Mesozoic. It united most of the territories that make up the existing continents of the Northern Hemisphere today - Eurasia and North America, which in turn split from each other from 135 to 200 million years ago.

Pangea Ultima

It is assumed that in the future, the continents will once again gather in a supercontinent called Pangea Ultima.

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