Africa is a part of the world with an area of \u200b\u200bwith islands of 30.3 million km 2, this is the second place after Eurasia, 6% of the entire surface of our planet and 20% of the land.
Geographical position
Africa is located in the Northern and Eastern Hemispheres (most), a small part in the Southern and Western. Like all large fragments of the ancient mainland Gondwana, it has a massive outline, large peninsulas and deep bays are absent. The length of the continent from north to south is 8 thousand km, from west to east - 7.5 thousand km. In the north it is washed by the waters of the Mediterranean Sea, in the northeast by the Red Sea, in the southeast by the Indian Ocean, in the west by the Atlantic Ocean. Africa is separated from Asia by the Suez Canal, from Europe by the Strait of Gibraltar.
Main geographical features
Africa lies on an ancient platform, which determines its flat surface, which in some places is dissected by deep river valleys. On the coast of the mainland there are few lowlands, the northwest is the location of the Atlas Mountains, the northern part, almost completely occupied by the Sahara desert, is the Ahaggar and Tibetsi highlands, the east is the Ethiopian highlands, the southeast is the East African plateau, the extreme south is the Cape and Draconian mountains The highest point in Africa is Mount Kilimanjaro (5895 m, Masai plateau), the lowest is 157 meters below sea level in Lake Assal. Along the Red Sea, in the Ethiopian Highlands and to the mouth of the Zambezi River, the world's largest fault in the earth's crust stretches, which is characterized by frequent seismic activity.
Rivers flow through Africa: Congo (Central Africa), Niger ( West Africa), Limpopo, Orange, Zambezi (South Africa), as well as one of the most full-flowing and longest rivers in the world - the Nile (6852 km), flowing from south to north (its sources are on the East African plateau, and it flows into delta in the Mediterranean). The rivers are high-water only in the equatorial zone, due to the large amount of precipitation there, most of them are characterized by high flow speed, have many rapids and waterfalls. In lithospheric faults filled with water, lakes formed - Nyasa, Tanganyika, the largest freshwater lake in Africa and the second largest after Lake Superior ( North America) - Victoria (its area is 68.8 thousand km 2, length 337 km, max depth - 83 m), the largest saline drainless lake - Chad (its area is 1.35 thousand km 2, located on the southern outskirts of the world's greatest desert Sahara).
Due to Africa's location between two tropical belts, it is characterized by high total solar radiation, which gives the right to call Africa the hottest continent on Earth (the highest temperature on our planet was recorded in 1922 in El Azizia (Libya) - +58 C 0 in the shade).
In Africa, there are such natural areas as evergreen equatorial forests (the coast of the Gulf of Guinea, the depression of the Congo), in the north and south turning into mixed deciduous-evergreen forests, then comes the natural zone of savannahs and light forests, extending to Sudan, East and South Africa, in the north and south of Africa, savannas are replaced by semi-deserts and deserts (Sahara, Kalahari, Namib). In the southeastern part of Africa there is a small zone of mixed coniferous-deciduous forests, on the slopes of the Atlas Mountains - a zone of hard-leaved evergreen forests and shrubs. The natural zones of mountains and plateaus are subject to the laws of altitudinal zonation.
African countries
The territory of Africa is divided among 62 countries, 54 are independent, sovereign states, 10 are dependent territories belonging to Spain, Portugal, Great Britain and France, the rest are unrecognized, self-proclaimed states - Galmudug, Puntland, Somaliland, the Saharan Arab Democratic Republic (SADR). For a long time, the countries of Asia were foreign colonies of various European states and only by the middle of the last century gained independence. Africa is divided into five regions based on geographic location: North, Central, West, East and South Africa.
List of African countries
Nature
Mountains and plains of Africa
Most of the African continent is a plain. There are mountain systems, uplands and plateaus. They are presented:
- the Atlas Mountains in the northwestern part of the continent;
- the Tibesti and Ahaggar uplands in the Sahara desert;
- Ethiopian highlands in the eastern part of the mainland;
- Dragon Mountains in the south.
The highest point in the country is Mount Kilimanjaro, with a height of 5,895 m, belonging to the East African Plateau in the southeastern part of the mainland ...
Deserts and savannas
The largest desert zone of the African continent is located in the northern part. This is the Sahara Desert. In the southwestern side of the continent is another smaller desert, the Namib, and from it inland to the east is the Kalahari Desert.
The territory of the savanna occupies the main part of Central Africa. In terms of area, it is much larger than the northern and southern parts of the mainland. The territory is characterized by the presence of pastures typical for savannahs, low shrubs and trees. The height of grassy vegetation varies depending on the amount of precipitation. It can be almost desert savannas or tall grasses, with grass cover from 1 to 5 m in height...
Rivers
On the territory of the African continent is the longest river in the world - the Nile. Its direction of flow is from south to north.
In the list of major water systems of the mainland, Limpopo, Zambezi and the Orange River, as well as the Congo, which flows through the territory of Central Africa.
On the Zambezi River is the famous Victoria Falls, 120 meters high and 1,800 meters wide...
lakes
The list of large lakes of the African continent includes Lake Victoria, which is the second largest freshwater reservoir in the world. Its depth reaches 80 m, and its area is 68,000 square kilometers. Two more large lakes of the continent: Tanganyika and Nyasa. They are located in the faults of the lithospheric plates.
There is Lake Chad in Africa, which is one of the world's largest endorheic relict lakes that have no connection with the oceans ...
Seas and oceans
The African continent is washed by the waters of two oceans at once: the Indian and the Atlantic. Also off its coast are the Red and Mediterranean Seas. From the Atlantic Ocean in the southwestern part of the water form the deep Gulf of Guinea.
Despite the location of the African continent, coastal waters are cool. This is influenced by the cold currents of the Atlantic Ocean: the Canary in the north and the Bengal in the southwest. From the side indian ocean currents are warm. The largest are Mozambique, in the northern waters, and Needle, in the southern ...
Forests of Africa
Forests from the entire territory of the African continent make up a little more than a quarter. Here are subtropical forests growing on the slopes of the Atlas Mountains and the valleys of the ridge. Here you can find holm oak, pistachio, strawberry tree, etc. High in the mountains grow coniferous plants, represented by Aleppo pine, Atlas cedar, juniper and other tree species.
Closer to the coast there are cork oak forests, in the tropical area evergreen equatorial plants are common, for example, mahogany, sandalwood, ebony, etc...
Nature, plants and animals of Africa
The vegetation of the equatorial forests is diverse, about 1000 species grow here. various types Trees: ficus, ceiba, wine tree, oil palm, wine palm, banana tree, tree ferns, sandalwood, redwood, rubber trees, liberian a coffee tree etc. It is home to many species of animals, rodents, birds and insects living right on the trees. On earth live: bush pigs, leopards, African deer - a relative of the okapi giraffe, large apes - gorillas ...
40% of the territory of Africa is occupied by savannas, which are huge steppe areas covered with forbs, low, thorny shrubs, milkweed, and separately standing trees(tree-like acacias, baobabs).
Here there is the largest accumulation of such large animals as: rhinoceros, giraffe, elephant, hippopotamus, zebra, buffalo, hyena, lion, leopard, cheetah, jackal, crocodile, hyena dog. The most numerous animals of the savannah are such herbivores as: bubal (antelope family), giraffe, impala or black-footed antelope, different kinds gazelles (Thomson, Grant), blue wildebeest, in some places there are still rare jumping antelopes - springboks.
The vegetation of deserts and semi-deserts is characterized by poverty and unpretentiousness, these are small thorny shrubs, separately growing bunches of herbs. The oases grow a unique date palm Erg Chebbi, as well as plants resistant to drought conditions and salt formation. Grow in the Namib desert unique plants velvichia and nara, the fruits of which feed on porcupines, elephants and other animals of the desert.
Of the animals, various species of antelopes and gazelles live here, adapted to the hot climate and capable of traveling great distances in search of food, many species of rodents, snakes, and turtles. Lizards. Among mammals: spotted hyena, common jackal, maned sheep, Cape hare, Ethiopian hedgehog, gazelle dorcas, saber-horned antelope, Anubis baboon, wild Nubian donkey, cheetah, jackal, fox, mouflon, there are permanently living and migratory birds.
Climatic conditions
Seasons, weather and climate of African countries
The central part of Africa, through which the equator line passes, is located in the region low pressure and receives sufficient moisture, the territories north and south of the equator are in the subequatorial climatic zone, this is a zone of seasonal (monsoonal) moisture and an arid desert climate. The extreme north and south are in the subtropical climate zone, the south receives precipitation brought by air masses from the Indian Ocean, the Kalahari Desert is located here, the north receives the minimum amount of precipitation due to the formation of the region high pressure and the peculiarities of the movement of the trade winds, the largest desert in the world is the Sahara, where the amount of precipitation is minimal, in some areas it does not fall at all ...
Resources
African Natural Resources
By reserves water resources Africa is considered one of the least wealthy continents in the world. The average annual volume of water is only enough to meet primary needs, but this does not apply to all regions.
Land resources are represented by large areas with fertile land. Only 20% of all possible land is cultivated. The reason for this is the lack of the proper volume of water, soil erosion, etc.
The forests of Africa are a source of timber, including species of valuable varieties. The countries in which they grow, the raw materials are exported. Resources are misused and ecosystems are slowly being destroyed.
In the bowels of Africa there are deposits of minerals. Among those sent for export: gold, diamonds, uranium, phosphorus, manganese ores. There are significant reserves of oil and natural gas.
Energy-intensive resources are widely represented on the continent, but they are not used due to the lack of proper investments...
Among the developed industrial sectors of the countries of the African continent, one can note:
- the mining industry that exports minerals and fuels;
- the oil refining industry, distributed mainly in South Africa and North Africa;
- chemical industry specializing in the production of mineral fertilizers;
- as well as the metallurgical and engineering industries.
main products Agriculture are cocoa beans, coffee, corn, rice and wheat. In the tropical regions of Africa, oil palm is grown.
Fishing is poorly developed and accounts for only 1-2% of the total volume of agriculture. The indicators of animal husbandry are also not high, and the reason for this is the infection of livestock with tsetse flies ...
culture
The peoples of Africa: culture and traditions
About 8,000 peoples and ethnic groups live on the territory of 62 African countries, which in total is about 1.1 billion people. Africa is considered the cradle and ancestral home of human civilization, it was here that the remains of ancient primates (hominids) were found, which, according to scientists, are considered the ancestors of people.
Most of the peoples in Africa may number from several thousand people to several hundred living in one or two villages. 90% of the population are representatives of 120 peoples, their number is more than 1 million people, 2/3 of them are peoples with more than 5 million people, 1/3 - peoples with more than 10 million people (this is 50% of the total population of Africa) - Arabs , Hausa, Fulbe, Yoruba, Igbo, Amhara, Oromo, Rwanda, Malagasy, Zulu...
There are two historical and ethnographic provinces: North African (the predominance of the Indo-European race) and Tropical-African (the majority of the population is the Negroid race), it is divided into such areas as:
- West Africa. The peoples who speak Mande (Susu, Maninka, Mende, Wai), Chadian (Hausa), Nilo-Saharan (Songhai, Kanuri, Tubu, Zagawa, Mawa, etc.), Niger-Congo languages (Yoruba, Igbo, Bini, nupe, gbari, igala and idoma, ibibio, efik, kambari, birom and jukun, etc.);
- Equatorial Africa. Inhabited by Buanto-speaking peoples: Duala, Fang, Bubi (Fernandese), Mpongwe, Teke, Mboshi, Ngala, Komo, Mongo, Tetela, Cuba, Kongo, Ambundu, Ovimbundu, Chokwe, Luena, Tonga, Pygmies, etc.;
- South Africa. Rebellious-speaking peoples, and speaking Khoisan languages: Bushmen and Hottentots;
- East Africa. Bantu, Nilotic and Sudanese groups of peoples;
- North East Africa. The peoples speaking Ethio-Semitic (Amhara, Tigre, Tigra.), Cushitic (Oromo, Somalis, Sidamo, Agau, Afar, Konso, etc.) and Omotian languages (Ometo, Gimirra, etc.);
- Madagascar. Malagasy and Creoles.
In the North African province, the main peoples are considered to be Arabs and Berbers, belonging to the South European minor race, mainly practicing Sunni Islam. There is also an ethno-religious group of Copts, who are direct descendants of the Ancient Egyptians, they are Monophysite Christians.
Africa is dominated by plains (Fig. 53). Large mountain ranges cover only a fifth of the territory of the mainland. This is due to the fact that the mainland is based on the ancient African-Arabian platform. It has been established that the thickness of its sedimentary cover in some places is 7000 m. Folded structures collapsed under the influence of external forces, forming high plains. They stretch for hundreds of kilometers. This is the uplands Tibesti.
In the north and west of the mainland, individual blocks of the platform sank more often, forming huge depressions. They were repeatedly flooded by the sea. Now heights up to 1000 m prevail here, and therefore this whole part of the mainland is called Low Africa.
The southern and eastern part of the mainland, where the average heights exceed 1000 m, is called High Africa. Here the platform rose and fell, as a result of which, over time, Ethiopian highlands and East African plateau. At the same time, individual blocks of the platform in East Africa were sinking, thanks to "the theme arose a whole system of deep faults in the earth's crust, which formed Great African Rift (Fig. 54). Here magma erupted and volcanoes erupted. Some of them have already died out, such as the highest peak in Africa - Mt. kilimanjaro, the height of which is 5895 m (Fig. 55).
In High Africa, there are both single peaks and large mountain ranges at the edges of the platform. For a significant height, they are called mountains. These are, for example, dragon mountains(Fig. 56). The slopes of the mountains resemble giant steps descending to the hinterland of the mainland. To the coast of the Indian Ocean, mountains often break off with sheer slopes. Also steep slopes have old cape mountains, extending along the southern edge of Africa. (Use the atlas map to determine their age.)
Africa is "spreading". This can be explained by the continental drift hypothesis. After the split of Gondwana, Africa, unlike other continents, moved relatively little, since it was more influenced by tensile forces, rather than compressive forces. And the cracks in the earth's crust are proof of these stretching forces. The Red Sea is also a consequence of these faults. Scientists believe that East Africa may someday separate from the rest of the mainland, as the Arabian Peninsula did earlier, and before it, the island of Madagascar.
Under the influence of wind and flowing waters, numerous small forms of the earth's surface were formed in Africa. On a large territory of Africa, the wind is in charge, forming the so-called eolian landforms. These are sandy hills, dunes, dunes, many of which occupy huge areas and reach the height of skyscrapers (Fig. 57).
- At the heart of the mainland lies an ancient platform, which determined the predominance of the flat relief of Africa.
- Volcanism contributed to the formation of high uplands and individual volcanic peaks.
On this page, material on the topics:
The relief and geological structure of Africa briefly
Briefly about the relief of Africa
What are the main landforms of Africa that cross the Greenwich meridian
Gdz compendium on the geography of the relief of Africa
Geological development of Africa
Questions about this item:
Everyone remembers that Africa is the hottest continent on the planet. But few people know that Africa is also the "highest" of the continents, since it has the highest average height above sea level. The relief of Africa is different great variety and complexity: there are mountain systems, plateaus, large plains, active and long-extinct volcanoes.
The relief of any region, as is known, is closely connected with the tectonic and geological structure of the territory. The relief of Africa and the minerals of this continent are also associated with the tectonics of the mainland. Let's consider this question in more detail.
Plan for describing the relief of the territory of Africa
The relief of any continent is characterized according to a specific plan. The relief of Africa is described according to the following algorithm:
- characteristics of the mainland.
- Analysis of the history of the development of the earth's crust.
- Characterization of external and internal (exogenous and endogenous) factors of relief formation.
- Description common features relief of the continent.
- Highlighting the maximum and minimum height.
- Minerals and their distribution on the territory of the mainland.
Low and High Africa
The description of the relief of Africa should begin with the fact that the mainland, from an orographic point of view, is divided into two parts: High and Low Africa.
Low Africa occupies more than 60% of the entire area of the continent (geographically, these are the northern, western and central parts of Africa). Heights up to 1000 meters prevail here. High Africa covers the southern and eastern parts of the mainland, where the average heights are 1000-1500 meters above sea level. Here are the highest points - Kilimanjaro (5895 meters), Rwenzori and Kenya.
General characteristics of the African relief
Now consider the main features of the relief of Africa.
The main feature is that the relief of the mainland is mostly flat. Mountain ranges border the mainland only in the south and northwest. AT East Africa the relief is predominantly flat.
Such landforms of Africa predominate: plateaus, plains, highlands, plateaus, remnant peaks and volcanic massifs. At the same time, they are located on the territory of the mainland very unevenly: inside it there are mostly leveled surfaces - plains and plateaus, and along the edges - hills and mountain ranges. This feature is associated with the tectonic structure of Africa, most of which lies on the ancient platform of the Precambrian age, and along its edges there are areas of folding.
Of all the mountain systems in Africa, only the Atlas is young. In the east of the mainland, the huge East African Rift Valley stretches for more than 6,000 kilometers in length. Grandiose volcanoes formed in the places of its faults, and very deep lakes formed in the depressions.
It is worth listing the largest landforms in Africa. These include the Atlas, Draconian and Ethiopian highlands, the Tibesti and Ahaggar highlands, the East African plateau.
atlas mountains
The mountainous landforms of Africa are, as already mentioned, only in the south and northwest of the mainland. One of the African mountain systems is the Atlas.
The Atlas Mountains arose 300 million years ago as a result of the collision of the Eurasian and African plates. Later, they were raised to considerable heights due to neotectonic movements that took place at the end of the Paleogene. It is worth noting that earthquakes occur in this area even now.
The Atlas is composed mainly of marls, limestones, and also ancient volcanic rocks. The bowels are rich in metal ores, as well as phosphorites and oil.
This is the largest mountain system Africa, which includes several almost parallel mountain ranges:
- High Atlas.
- Rif.
- Tel Atlas.
- Middle Atlas.
- Sahara Atlas.
- Antiatlas.
The total length of the mountain range is about 2400 kilometers. The maximum heights are located on the territory of the state of Morocco (Mount Toubkal, 4165 meters). The average heights of the ridges range from 2000-2500 meters.
dragon mountains
This mountain system in the south of the mainland is located on the territory of three states - Lesotho, South Africa and Swaziland. The highest point of the Dragon Mountains is Mount Thabana-Ntlenyana with a height of 3482 meters. The mountains formed 360 million years ago, during the Hercynian era. They got such a formidable name due to their inaccessibility and wild appearance.
The territory is rich in minerals: platinum, gold, tin and coal. Unique and organic world Dragon Mountains, which has several endemic species. The main part of the mountain range (Drakensberg Park) is a UNESCO site.
The Drakensberg Mountains are the watershed boundary between the Indian Ocean basin and the upper reaches of the Orange River. They have a unique shape: their tops are flat, table-like, separated by erosion processes into separate plateaus.
Ethiopian highlands
The relief of Africa is strikingly diverse. Here you can find high mountain ranges of the Alpine type, hilly plateaus, vast plains and deep depressions. One of the most famous mainland is the Ethiopian Highlands, within which not only Ethiopia is located, but also 6 other African states.
This is a real mountain system with average heights of 2-3 kilometers and the highest point of 4550 meters (Mount Ras Dashen). Due to the specific features of the relief of the highlands, it is often called the "roof of Africa". In addition, this "roof" often shakes, seismicity remains high here.
The highlands formed only 75 million years ago. It consists of crystalline schists and gneisses overlain from above by volcanic rocks. Quite picturesque are the western slopes of the Ethiopian Highlands, indented by the canyons of the Blue Nile River.
Within the highlands there are rich deposits of gold, sulfur, platinum, copper and in addition, it is also an important agricultural region. It is considered the birthplace of coffee, as well as some varieties of wheat.
Mount Kilimanjaro
This volcano is not only the highest point of the mainland (5895 meters), but also a kind of symbol of all of Africa. The volcano is located on the border of two states - Kenya and Tanzania. From the Swahili language, the name of the volcano is translated as "sparkling mountain".
Kilimanjaro rises above the Masai plateau at a height of 900 meters, so visually it seems that the volcano is unrealistically high. Scientists do not predict the activity of the volcano in the near future (apart from the possible release of gases), although it was recently found that the lava is located 400 meters from the Kibo crater.
According to local legends, the volcano erupted about two centuries ago. Although there is no documentary evidence for this. The highest point of Kilimanjaro - Uhuru Peak - was first conquered in 1889 by Hans Meyer. Today, the speedy conquest of Kilimanjaro is practiced. In 2010, the Spaniard Kilian Burgada set a kind of world record by climbing to the top of the volcano in 5 hours and 23 minutes.
Relief of Africa and minerals
Africa is a continent with huge economic potential, which is characterized by huge reserves of various minerals. In addition, a more or less even, slightly dissected topography of the territory contributes to the development of industry and the construction of roads and other means of communication.
Africa is rich in minerals, on the basis of which metallurgy and petrochemistry can develop. Thus, the continent holds the absolute leadership in the world in terms of total reserves of phosphorites, chromites and tantalum. Africa also has large deposits of manganese, copper and uranium ore, bauxite, gold and even diamonds. On the mainland, they even distinguish the so-called "copper belt" - a belt of high mineral and raw material potential, stretching from Katanga to (DRC). In addition to copper itself, gold, cobalt, tin, uranium and oil are also mined here.
In addition, such regions of Africa as North Africa and West Africa (its Guinean part) are also considered very rich in the presence of minerals.
So you got acquainted with the features of the relief of the hottest continent on Earth. The relief of Africa is unique and diverse, here you can find all its forms - mountain ranges, plateaus and plateaus, highlands, hills and depressions.
1. Why does the study of the features of the mainland begin with determining its geographical position?
The study of geographic location should begin with the definition of geographic location. It is the geographical location that determines many characteristics of the mainland: the amount of heat and the set of climatic zones, the prevailing winds, the amount of precipitation, coastal currents.
2. What is the main feature of Africa is determined by its geographical position?
Due to its geographical position, Africa is the hottest continent.
3. Fill in the gaps in the sentences using textbook text and a map of Africa.
The area of mainland Africa is 30.3 million km2. The population of the mainland is more than 900 million people. Africa is the hottest continent on earth. Africa is located in subtropical, tropical, subequatorial and equatorial climatic zones. The shores of the mainland are poorly dissected. The largest island - Madagascar - is of continental origin, it is located about 400 km east of Africa.
5. Remember from the geography course of grades 5-6 what types of plains are distinguished by height. Via physical map draw a diagram "Views of the plains of Africa." Give examples of each type of plain.
In terms of height, the plains are low (up to 200 m), elevated (200-500 m), highlands (above 500 m).
6. Determine what types of plains are shown on the African relief profile in Figure 66 in the textbook.
The profile shows elevated plains and plateaus.
9. Here are four climate charts. Determine which climate zone they characterize.
1 - tropical;
2 - subtropical;
3 - equatorial;
4 - subequatorial.
10. What natural zone and what geographical object are we talking about in the following passage?
Desert natural zone, Sahara.
13. Apply to contour map and sign the warm and cold currents off the coast of Africa.
Cold - Canary, Benguela, Samal current.
Warm - Guinea, Angolan, for Cape Agulhas, Mozambique for.
14. Using the map of climatic zones in the atlas, determine in which main and transitional climatic zones Africa is located.
The main belts are equatorial and tropical.
Transitional belts - subequatorial, subtropical.
15. Determine on the map which basins of the oceans the rivers belong to:
Nile - Atlantic Ocean;
Congo - Atlantic Ocean;
Zambezi - Indian Ocean;
Niger - Atlantic Ocean;
Limpopo - Indian Ocean;
Senegal - Atlantic Ocean.
18. How would you dress if you were at the mouth of the Congo River? Justify the answer.
The mouth of the Congo River is located in the subequatorial zone in the natural zone of variable-humid forests. In conditions high temperature and humidity, it is better to wear light clothing from natural materials. However, for security, it needs to be closed.
19. Imagine that the island of Madagascar will shift south by 300. How will the climate and natural areas on the island change?
If the island moves 300 south, it will be within the temperate and subantarctic climatic zones. Temperatures will be much lower. Tropical forests will be replaced by mixed and coniferous, in the extreme south - by tundra.
20. One of the major problems on the African continent is deforestation. Continue the chain of changes in the natural complex that will occur as a result of the destruction of forests in order to harvest valuable breeds trees for export.
Determine which part of Africa is experiencing the most intensive deforestation. What can you suggest to solve the problem?
Intensive deforestation is taking place in the Congo Basin. Considering that forests are climatic and hydrological regulators, deforestation in the equatorial regions of the Earth can lead to radical climate change. In this regard, there is a need to protect not just some forest areas or typical forests, but the entire forest fund of the planet, all logging must certainly be accompanied by reforestation.
21. What letter on the map (Fig. 5) indicates Cape Agulhas?
BUT); AT); WITH); D)
22. What letter on the map (Fig. 6) indicates the Atlas Mountains?
BUT); AT); WITH); D)
23. Almost the entire continent experiences the action of winds:
1) monsoons;
2) trade winds;
3) Western
2) trade winds
24. in figure 7, the numbers indicate:
1) the Congo River;
2) Atlas mountains;
3) the Nile River;
4) Dragon mountains;
5) Lake Victoria;
6) Ethiopian highlands;
7) Lake Tanganyika
8) Lake Chad.
25. Dry riverbeds in Africa are called:
3) meanders
26. Specify the excess:
3) Victoria;
4) Orange
3) Victoria.
27. The Zambezi River is full-flowing:
3) autumn;
28. The population of Africa is:
1) 900 million people;
2) 500 million people;
3) 1.5 billion people
1) 900 million people
1) in the Nile Delta;
2) in the Sahara;
3) on the coast of the Gulf of Guinea
1) in the Nile Delta
30. What letter on the map (Fig. 8) indicates Angola?
BUT); AT); WITH); D)
31. What letter on the map (Fig. 9) is Nigeria?
BUT); AT); WITH); D)
32. Match:
Peoples Where they live
1) pygmies; A) South Africa
2) drills; B) the Congo basin;
3) Berbers; B) Kalahari
4) Bushmen; D) Sugar
1-B; 2-A; 3-G; 4-B.
33. Most of Africa is occupied by a natural zone:
1) savannas and light forests;
2) deserts and semi-deserts;
3) humid equatorial forests;
4) forest-steppes and steppes
1) savannas and woodlands
34. What letter on the map (Fig. 10) indicates the zone of savannas and light forests?
BUT); AT); WITH); D)
35. Choose the only false statement:
1. 40% of the area of Africa is occupied by savannahs.
2. The Benguela Current contributed most to the formation of the Namib Desert.
4. There is no temperate climate zone in Africa.
3. Extreme northern point Africa is Cape Piai.
36. Which of the statements is correct?
A) Baobab is a characteristic tree of the African savannas.
b) The Strait of Gibraltar separates Africa from the Arabian Peninsula.
1) only A is true;
2) only B is true;
3) both are true;
4) both are wrong
Creating a Majority modern forms relief of Africa occurred in the Neogene and at the beginning of the Quaternary, when differentiated tectonic movements Inland depressions and uplifts separating them were formed, the highest eastern margin of Africa was fragmented, and in the North-West, the formation of the Atlas Mountains was basically completed.
The flat relief of a large part of Africa is the result of a long peneplenization. AT modern era the leveling surfaces created in the Neogene are most developed; the levels of these surfaces - vast plains and plateaus, composed mainly of sedimentary rocks, rise from North to South, from Low Africa to High Africa. Most of the plateaus and highlands, rising in steep ledges above the Neogene leveling surfaces, are remnant massifs preserved from destruction, mainly crystalline, often also flat-topped, leveled by previous cycles of peneplenization up to the Early Mesozoic.
In modern and past geological epochs, the dissection of the surface of Africa was hampered by the widespread development of armoring "shells" - lateritic crusts in areas of hot and variable humid climates and salt crusts in areas of a desert climate. Therefore, Africa is a continent with a predominance of table landforms, alternating in places with cuest ledges of monoclinal sedimentary suites. Only in the zones of manifestation of fault tectonics (mainly along the eastern margin of the mainland), Hercynian and Alpine folding (in the Cape and Atlas mountains), does the relief acquire a mountainous character with alternating ridges, intermountain valleys and basins.
The relief of Africa is very characteristic of stepped plains, plateaus and plateaus, crowned with numerous remnant peaks. Plains and plateaus lie mainly inside the mainland, most of the hills and ridges are located on its outskirts, lowlands - mainly along the coasts of the oceans and seas.
The Atlas Mountains frame Low Africa from the North-West. They form a complex system of ridges with an average height of 1200-1500 m, mainly folded in the North, along the Mediterranean coast, and folded-blocky in the South. They reach their highest height in the West, in the High Atlas (Tubkal, 4165 m). The northern ridge of the Rif and the High Atlas frame the plateau of the Moroccan Meseta, stepwise descending to the coast of the Atlantic Ocean. Numerous spurs extending from the ridges to the East of the High Atlas surround high-mountain basins, united by the name High Plateaus.
Most of Low Africa is occupied by the plains and plateaus of the Sahara and Sudan, extending in the South to the North Guinea Upland and the Azande Upland. These plains and plateaus surround the highlands of Ahaggar (Tahat, 3003 m) and Tibesti (Emi-Kusi volcano, 3415 m) in the Central Sahara, where the ancient base of the mainland, raised to the highest height for Low Africa, is blocked by lava flows and crowned with cones extinct volcanoes. Ahaggar and Tibesti are surrounded by cuesta ridges, reaching a height of 1000 m and framed by a ring of lower (500-1000 m high) plateaus (Tanezruft, Hamada-el-Hamra, Tademait, etc.). The plateau is adjoined by accumulative plains in the Western, Northern and Eastern Sahara, as well as in Sudan, lying in the troughs of the ancient basement of the African Platform. Most of the Pre-Atlas trough (in the northwestern part of the Sahara) is filled with demolition products from the Atlas Mountains and is expressed in relief as piedmont plains. Wide strips of lowlands go to the coasts of the Mediterranean Sea and the Atlantic Ocean.
In addition to Ahaggar and Tibesti, the crystalline base of the platform is exposed in the Etbay Ridge (Oda, 2259 m), which rises steeply (along the fault line) above the Red Sea, on the Darfur plateau, which separates the White Nile and Chad depressions, and on the El-Eghlab plateau separating the El-Dzhuf basin from the Atlantic lowland.
On the plains of the Sahara and Sudan, differences in relief associated with exogenous processes are clearly manifested. In the Sahara, where physical weathering dominates, gravelly deserts (hamads), pebble (regs) and clayey (serirs) are classically represented, occupying most of its area. Sands cover about 1/5 of the surface of the Sahara and stand out as a special type of sandy deserts (ergs). At the same time, traces of the impact of the humid climate of the pluvial epochs of the Quaternary period have been preserved in the relief of the Sahara - dry channels (oueds), lake basins, the bottoms of which are now occupied by solonchaks, etc.
To the south of the Sahara, in conditions of a variable humid climate, both physical weathering (mainly in the dry season) and water erosion (mainly in the wet season) take part in the formation of the relief. Plateaus and plateaus rise above the plains of Sudan - Air (1900 m), Ennedi (1450 m), Darfur (3088 m) and others. The plateaus of southern Sudan are dissected by wide, slightly incised valleys of permanent rivers, carrying a large amount of alluvium deposited during floods in the depressions of the Nigerian depression (in the region of the so-called mainland Niger delta), around Lake Chad and in the White Nile depression.
The North Guinea Upland, rising along the coast of the Gulf of Guinea, is a protrusion of the ancient crystalline foundation, dissected by tectonic troughs and faults into separate massifs, reaching greatest height in the East (Joe Plateau, 1735 m) and in the West (Bintimani, 1948 m). In the extreme South of Low Africa, in the closed syneclise of the African platform, lies the Congo depression, the bottom of which is bordered by an amphitheater of terrace-like plateaus from 500 to 1000 m high. The depression is surrounded on all sides by protrusions of an ancient crystalline foundation: in the North - Azande Plateau (Ngaya, 1388 m, Congo-Shari watershed); in the West - the Adamaua mountains (height up to 3008 m); in the South - the latitudinal watershed of the Congo - Zambezi rivers (Moko, 2610 m). The Congo Basin is separated from the Atlantic Ocean by the South Guinea Upland (1500-2000 m high), with the characteristic complex relief of a mountainous country, densely dissected by many rivers; to the East, above the depression, a steep wall rises the East African Plateau broken by faults.
High Africa includes the entire uplifted and tectonically fragmented eastern margin of Africa, including the Ethiopian Highlands, the East African Plateau, and South Africa. In High Africa, not only the absolute heights of the continent increase, but also the vertical dissection of the relief. This means that the crystalline rocks of the African platform are exposed; lava plateaus and volcanic cones are widespread.
The Ethiopian highlands lie on average at an altitude of 1800-2000 m, the highest high peak is Mt. Ras Dashen (4623 m). To the East and South-East, it abruptly breaks off along the lines of meridional faults to the Afar depression, where the deepest depression in Africa is located - Lake. Assal (-153 m), and to the Ethiopian graben, in the West it gradually decreases to the plains of Sudan. The western slopes of the highlands are cut by deep canyons of the Blue Nile and its tributaries.
Lying to the South-East of the Ethiopian Highlands, the Somali Peninsula is formed in the northern part by stepped plateaus, breaking off in the South-East to the accumulative coastal lowland.
The East African Plateau (average height is about 1000 m) is broken by numerous tectonic faults. In the relief, basement plains, fault depressions and ledges, blocky mountains, lava plateaus and volcanic cones alternate (among them the highest peak of Africa - Mt. Kilimanjaro, 5895 m).
Almost all of South Africa is occupied by the Kalahari Plain, similar in shape to the Congo Basin, but elevated by 900-1000 m above sea level. Edge mountains and plateaus rise stepwise above the Kalahari. In the North - this is the latitudinal watershed of the Congo-Zambezi rivers, in the East, between the Zambezi and Limpopo rivers - the Matabele plateau, abruptly breaking off along the fault line to the coastal lowland of Mozambique. To the south of Limpopo, the Weld Plateau, the Dragon Mountains, and the Basuto Highlands rise in steps over the Kalahari. The highest peaks of the Basuto Highlands, armored with basalt covers, retain flat shapes and reach the highest height in South Africa (Tabana-Ntlenyana, 3482 m). From the south, the Kalahari closes the Upper Karoo plateau. Dolerite intrusions crown its highest southern regions (Sniuberge mountains, 2505 m). From the West, the plateaus and plateaus of Namaqualand, Damaraland, Kaoko and the Serra da Shela range rise above the Kalahari. The marginal uplifts, framing the Kalahari, in the East and West abruptly break off to the coastal lowlands, in the South - to the B. Karru depression. The steep cliff of the Great Ledge, clearly expressed in the relief, forms not only an orographic, but also a landscape boundary, stretching from the river. Limpopo (to the East) to the river. Kunene (in the West).
In the extreme south of the mainland, the folded-blocky Cape Mountains (height up to 2326 m) rise, the flat-topped ridges of which are separated by wide longitudinal valleys (Small Karru and others) and are crossed by narrow transverse gorges.
Much in common with the relief of South Africa is the relief of the island of Madagascar, a continental block separated from South Africa by the graben of the Mozambique Channel.
