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Lakes of Africa. Great lakes of Africa. The deepest lake in Africa. Tanganyika is the deepest lake in Africa

10.10.2019

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Africa is the second largest continent 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 the name given to the part of the world consisting of the continent of Africa and adjacent islands. The area of Africa is 29.2 million km², with islands about 30.3 million km², thus covering 6% of the total surface area of the Earth and 20.4% of the land surface. There are 55 states in Africa.

Africa's population is about a billion people. Africa is considered the ancestral home of humanity: it is here that the most ancient remains of early hominids and their probable ancestors were found.

The African continent crosses the equator and several climate zones; it is the only continent that stretches from the northern subtropical climate zone to the southern subtropical climate zone. Due to the lack of constant precipitation and irrigation - as well as glaciers or the aquifer of mountain systems - there is practically no natural regulation of climate anywhere except the coasts.

Extreme points

Northern - Cape Blanco (Ben Sekka, Ras Engela, El Abyad)

South - Cape Agulhas (Agullas)

Western - Cape Almadi

Eastern - Cape Ras Hafun

Africa covers an area of 30.3 million km². The length from north to south is 8 thousand km, from west to east in the northern part - 7.5 thousand km.

For the most part it is flat, in the north-west there are the Atlas Mountains, in the Sahara there are the Ahaggar and Tibesti highlands. In the east is the Ethiopian Highlands, to the south of it is the East African Plateau, where the Kilimanjaro volcano (5895 m) is located - the highest point of the continent. In the south are the Cape and Drakensberg Mountains. The lowest point (157 meters below sea level) is located in Djibouti, this is the salt lake Assal. The deepest cave is Anu Ifflis, located in the north of Algeria in the Tel Atlas Mountains.

The structure of the continent's surface is quite peculiar. The relief of Africa is vast plains changing high mountains and endless deserts. Plains and plateaus with heights from 200 to 1000 m predominate; there are very few lowlands. The most extensive plateaus are East African and South African. Elevated areas alternate with basins, the most extensive of which are the Kalahari Basin, the Congo Basin, etc.

The relief features are associated with the history of the development of the continent. The continent is based on the ancient African-Arabian Plate - part of the split Gondwana. The platform was formed in the Archean and Proterozoic and over 2 - 3 billion years acquired greater stability. Only the Atlas Mountains in the north and the Cape in the south were created by later movements of the earth's crust.

The huge African block experienced uplift and subsidence, while the northern part of the continent more often sank than rose and was flooded with seas. The crystalline foundation of the platform is covered by sedimentary rocks and only comes to the surface in the center of the Sahara and on the coast of the Gulf of Guinea.

Relief of the Eastern and South Africa was formed differently - the uplift of the earth's crust prevailed, giant faults, horsts and grabens were formed. Volcanic activity was actively developing. There are many lava plains here, the grabens are occupied by lakes. Volcanic eruptions and earthquakes still occur today. The rift belt contains volcanoes, including highest point mainland - Kilimanjaro volcano (5895 meters)

Africa is the hottest continent on the planet. The reason for this is the geographical location of the continent: the entire territory of Africa is located in hot climate zones and the continent is intersected by the equator line. It is in Africa that the hottest place on Earth is located - Dallol.

Central Africa and the coastal regions of the Gulf of Guinea belong to the equatorial belt, where there is heavy rainfall throughout the year and there is no change of seasons. To the north and south of the equatorial belt there are subequatorial belts. Here, in summer, humid equatorial air masses dominate (rainy season), and in winter, dry air from tropical trade winds (dry season). North and south of the subequatorial belts are the northern and southern tropical belts. They are characterized by high temperatures and low precipitation, which leads to the formation of deserts.

In the north is the largest desert on Earth, the Sahara Desert, in the south is the Kalahari Desert, and in the southwest is the Namib Desert. The northern and southern ends of the continent are included in the corresponding subtropical zones.

High temperatures throughout the year in most of Africa depend on the height of the sun above the horizon and strong insolation. On a large part of the continent, the average annual temperature exceeds 20 °C. The northern part of Africa is more massive, so in general it warms up more than the southern part, and there is the highest average monthly temperature (35...40 ° C), as well as the highest maximum temperature (up to 58 ° C) observed on Earth.

All of Africa is characterized by significant daily temperature fluctuations as a manifestation of the continental climate. For example, in the Sahara, daily temperature amplitudes can reach 50 °C.

Precipitation is distributed extremely unevenly across the continent. Regular and heavy convective rains fall in the equatorial part, approximately between 5° N latitude. and 10° S The maximum precipitation in Africa (about 10,000 mm) was recorded on the slopes of the Cameroon massif, facing the prevailing southwesterly winds.

Distribution inland waters closely related to relief and climate. Approximately one second of the continent belongs to areas of internal drainage, since large areas of the continent receive little rainfall. Where there is a lot of precipitation, the river network is dense. In other words, the river network is unevenly distributed on the mainland.

The East African Plateau is a watershed, so most of the rivers flow into the Atlantic Ocean. The rivers of Africa have many rapids and waterfalls, and they are of little use for navigation, but they have huge reserves of hydroelectric power. Almost all rivers are fed mainly by rain. In areas with an equatorial climate, they are full of water all year round and form a dense river network. In subequatorial zones, rivers are full only during the rainy season. Territories with a dry tropical climate are almost devoid of surface water, but there are artesian basins. There are often dry riverbeds - wadis, rarely filled with water from occasional rains. On rivers in the subtropical zone, the water level rises only during the rainy season, on the coast Mediterranean Sea this happens in winter.

In terms of total annual flow (5390 cubic km), Africa is inferior to Asia and South America. In terms of basin area, length, and flow volume, many rivers are among the largest in the world (Nile, Congo). The distribution of the river network and flow across the continent is extremely uneven, which depends mainly on differences in climatic conditions, topography and the nature of the rocks of certain areas. Along with areas with a dense hydrographic network and large lakes, vast areas of Africa are almost or completely devoid of local river networks. Many rivers do not reach the ocean and end in inland drainage basins. Almost all the continent's rivers are fed by rain. Only in deserts and semi-deserts do they feed on groundwater, and on the high peaks of the Atlas and East Africa mountains the sources of rivers are also fed by meltwater from snow and glaciers. The Congo, Zambezi, Niger, Senegal, Orange, Nile and others rivers flow through the continent. The Nile is the longest river in the world. The rivers of Africa are high-water only in its equatorial part, since there is a lot of precipitation there. Many rivers in Africa are fast, rapids, and abound with waterfalls; lakes are concentrated mainly in the east, where water fills the cracks of faults.

The total area of East African lakes, according to rough estimates, exceeds 170 thousand km2. This is twice the territory of Austria and six times that of Belgium. The volume of water contained in the Great African Lakes is also enormous. In order to fill the deepest of them - Tanganyika, even such a high-water river as the Congo would take a quarter of a century, and, say, the Volga - about 120 years (and this is not taking into account the loss of water due to evaporation, with taking into account their named dates would have to be increased significantly). The largest of the Great Lakes of East Africa, Victoria, in terms of area, ranks third among the world’s lakes (after the Caspian Sea and Lake Superior in North America) and on the second - among freshwater lakes. The other two largest East African lakes, Tanganyika and Nyasa, rank seventh and ninth among the world's lakes by the same indicator, and if we count only freshwater lakes, then fifth and seventh, respectively.

Most lakes, especially large ones, are concentrated in eastern Africa. Their basins are located in narrow elongated depressions in the East African fault zone of the earth's crust. These lakes have steep banks and great depths. The deepest in Africa and the second deepest in the world after Lake Baikal is Lake Tanganyika (1,435 m). With a width of 60 km, it stretches for 650 km! The lake is runoff, so the water in it is fresh. It has a unique organic world and is exceptionally rich in fish. There are about 250 species of fish in the lake, most of which are endemic. Lake Nyasa also has an elongated shape and is of tectonic origin. However, it is inferior to Tanganyika in area and depth. The lake is fresh and rich in fish.

Lake Victoria looks like the sea. The largest lake in East Africa and the entire continent, Victoria, is not a rift lake. It occupies a vast flat basin, also created by tectonic processes, but mainly not by faults (although in some places along the shores of the lake they apparently occur), but by a slow, relatively small vertical amplitude subsidence of the axial part of the East African arch. Lake occupies a gentle tectonic trough in the northern part of the East African Plateau, dammed from the north by a lava flow. It arose in the middle of the Anthropocene period during the formation of the Albert and Edward lake depressions in the central branch of the East African Rift Zone, which disrupted the previous flow into the Congo Basin. New system The flow was turned east, towards a trough on the plateau, where a huge reservoir was formed, the area of which was especially large in pluvial eras. The ancient lake received flow to the west, into Lake Albert and further into the Nile system through the river. Victoria Nile at the formation of Murchison Falls. Victoria and Lake Kyoga, which lies to the north, are relics of an ancient reservoir. In the same shallow depressions of the ancient foundation lie lakes Kyoga and Bangweulu. It is the largest lake in Africa and one of the largest in area in the world. The lake was formed not in a fault, but in a trough of the platform. Therefore, the lake is relatively shallow (up to 80 m) and has low-lying shores, strongly dissected by bays and peninsulas. The lake is located at an altitude of 1134 m. Area - 68 thousand km², volume - 8400 km². This is the second largest freshwater lake in the world (after Lake Superior). The greatest length is 320 km, width 274 km. The average depth is 40 m (the greatest is 80 m). After the construction of the Owen Falls dam in 1954, the lake was turned into a reservoir. There are many islands on the lake. The high-water river flows into Kagera, the river flows out. Victoria Nile. Fishing (more than 100 species of fish, many endemics) and shipping are developed on the lake. The main ports are Mwanza, Bukoba (Tanzania), Entebbe, Jinja (Uganda), Kisumu (Kenya). On about. Rubondo (Tanzania) - national park. Hurricane winds, often accompanied by thunderstorms, cause strong storms on the lake.

The oldest lake in Africa is Lake Chad, which lies south of the Sahara in a huge flat depression. It is the remnant of an ancient lake that existed in past geological eras. The lake is shallow (7 m). In the dry season, its area is halved, and in the rainy season it increases again. The banks are low-lying, swampy in many places, covered with thickets of reeds and reeds.

The role of lakes in people's lives is great. Their transport role is very important for Africa, since the rivers are “blocked” by numerous rapids. The lakes are rich in fish and are sources of fishing.

The freshwater system of the African continent includes the largest and deepest lakes on the planet. Most of them belong to the Great African Lakes, which have a connection with the Nile. But many geographers include only the following African lakes directly among the Great Lakes: Victoria, Edward and Albert. Because only they have a natural outlet to the White Nile. Lake Tanganyika has a natural flow into the Congo water system, and Lake Malawi is connected to the Zambezi River. All lakes in Africa (photos below) have very beautiful natural landscapes.

Largest lakes in Africa

Name	Greatest depth (in meters)	Height above sea level (in meters)
Victoria			Tanzania, Kenya, Uganda
Tanganyika			Tanzania, Zambia, Congo, Burundi
			Tanzania, Mozambique, Malawi
			Chad, Cameroon, Nigeria, Niger
			Kenya, Ethiopia
Mobutu-Sese-Seko			Uganda, Congo
			Zambia, Congo
Bangweulu

			Rwanda, Congo
			Uganda, Congo

Based on the origin of the lake basin in Africa, there are 3 types of lakes: 1) tectonic, 2) relict, 3) volcanic.

The lakes of East Africa are for the most part of tectonic origin. The Great Lakes are created by the Great Rifts. Most of these lakes lie at the bottom of rift basins, which began to fill with water almost from the moment of their origin (or, more precisely, their revival as a result of recent movements of the earth’s crust). Among the rift lakes there are large and small, deep and shallow, fresh and salty. But almost all of them have a characteristic elongated shape, determined by the outlines of the rifts themselves. As a rule, lakes are located in fault depressions (grabens) in a row, one after another, forming long chains or garlands. The first thing that catches your eye when looking at physical card East Africa is a unique chain of large lakes, starting in the south with Nyasa and continuing with the Western Rift lakes - Rukwa, Tanganyika, Kivu, Edward and Albert. Another lake garland is located on the territory of the Eastern Rift and its spurs; here, however, there is only one big lake- Rudolf, but there are many small ones. Mveru stands somewhat apart among the lakes of fault origin: it occupies an independent graben, which is believed to be a side branch of the Western Rift, but has no direct connection with it in the modern topography. Almost all large lakes in Africa lie in deep rift basins (grandiose faults in the earth's crust) on the East African Plateau and are classified as tectonic (Tanganyika, Nyasa, Edward, Albert, Kyoga, Mweru Rudolf, Victoria). Most of them are deep and bordered by steep slopes. Basins of lakes Tanganyika and Nyasa. Tectonic and volcanic processes in East Africa did not occur simultaneously, but over a very long period. It is therefore natural that East African lakes have different ages. Among them there are “old people”, formed millions of years ago, there are also “young people”, whose age is measured “only” in thousands of years (and in some small lakes - hundreds and even tens of years). Almost all large lakes are considered “old people”. They have undergone a long and complex evolution. Their level and outlines changed repeatedly depending on the movements of the earth's crust and climate fluctuations, primarily moisture conditions. During eras of humid climates, the size of the lakes increased, and some bodies of water now isolated from each other merged together. On the contrary, during dry periods the area of lakes was greatly reduced, and many of them dried up altogether. All these and other features of their history left a noticeable imprint on the modern appearance of lake basins and the lakes themselves, and had a strong influence on the development of life in lake waters.

From a hydrographic point of view, the lakes of East Africa can be divided into four large groups. The first is formed by the famous Nile lakes. The upper, “head”, natural reservoir of the Nile system is Lake Victoria, which receives many tributaries - including the Kageru, the source of the Nile farthest from the mouth. Emerging from this vast natural reservoir, the Victoria Nile River flows through shallow Lake Kyoga and then flows into Lake Albert; this latter also receives the Semliki River - the drainage of Lake Edward. Finally, the Albert Nile River emerges from Lake Albert - the upper reaches of the White Nile, the main (in length) branch of the great African river, which ends its path by flowing into the Mediterranean Sea.

The second group consists of four lakes belonging to the Conto basin, and thereby to the Atlantic Ocean basin. Two of them, Bangweulu and Mweru, are parts of a complex lake-river system (Chambeshi River - Lake Bangweulu - Luapula River - Lake Mweru - Lovua River), which is considered the eastern source of the Congo. The other two lakes - Kivu and Tanganyika, connected by the Ruzizi River, flow into the Congo (Lualaba) through the Lukugu River.

The third hydrographic element is Lake Nyasa, which sends its waters along the Shire River to the Zambezi. Apart from this, there are no large lakes belonging to the Indian Ocean basin in East Africa.

As the fourth and last group Numerous lakes that do not drain into the ocean can be identified. These are, firstly, all the lake reservoirs of the Eastern Rift from Lake Rudolf in the north to Lake Manyara in the south; secondly, Lake Rukwa in the southern branch of the Western Rift; thirdly, Lake Shirva in one of the side spurs of the Nyasa rift. Unlike the lakes of the three previous groups, in which the water is fresh (only in Kivu it is brackish), the reservoirs of the fourth group are mostly salty. In addition to those listed, there are other closed lakes in East Africa (for example, many crater lakes), but they are all insignificant in size and are not of particular interest to us now.

Nyasa is a tectonic lake formed as a result of a fracture in the earth's crust. Depression is a depression earth's surface, the bottom of which lies below ocean level, crypto is a prefix to the name of the structure, denoting its thin appearance. The third largest lake in the Great Rift Valley in East Africa, which fills a deep depression in earth's crust between Malawi, Mozambique and Tanzania. The lake runs from north to south, length is 560 km, depth is 706 m. It is the ninth largest and third deepest (after Baikal and Tanganyika) among freshwater reservoirs in the world. It contains 7% of the world's liquid fresh water and creates the most diverse lake ecosystem in terms of the number of species, most of which are endemic.

Rice. Lake Nyasa. Photo from space.

The lake fills a crack in the earth's crust at the southern end of the Great Rift Valley, as a result of which it is elongated in the meridional direction and has a length of 584 km, its width varies from 16 to 80 km. The surface of the lake lies at an altitude of 472 m above sea level, its area is 29,604 km², the average depth is 292 m, the maximum is 706 m, that is, the deepest places of the lake are below sea level. The total volume of the lake is 8,400 km³. The depths gradually increase from south to north, where the steep slopes of the mountains surrounding the lake suddenly burst straight into the water. Elsewhere on the coast, the mountains and peaks that rise along the edges of the rift valley are separated from the lake by a wide coastal plain; where large rivers flow into the lake, the coastal plain expands and connects with the river plain, going deeper into the mountain ranges. As a result, the coastline topography varies from rocky cliffs to extensive beaches. The coastal plains are especially wide in the northwest, where the Songwe River flows into the lake, as well as in the southern part of the coast.

The bottom of the lake is covered with a thick layer of sedimentary rocks, in some places up to 4 km thick, which indicates the great age of the lake, which is estimated at least several million years.

The main part of the lake basin is occupied by highlands and mountains, which are the boundaries of the rift valley. The highest of them are the Livingstone Mountains in the northeast (up to 2000 m) and the Nyika Plateau and the Vipya and Chimaliro Mountains in the northwest and the Dowa Hills in the west; in the south the terrain gradually decreases. The lake basin is much wider to the west of the lake. In the east, the mountains come close to the water, and the basin narrows, expanding only in the northeast thanks to the Ruhuhu River, which cuts through the Livingston Mountains. The lake is fed by 14 year-round rivers, including the most important Ruhuhu, Songwe, North and South Rukuru, Dwangwa, Bua and Lilongwe . The lake's only external drainage is the Shire River, which emerges from the lake in the south and flows towards the Zambezi. Despite the large volume of the lake, the volume of its flow is small: of the approximately 63 km3 of water entering the lake annually, only 16% flows through the Shire River, the rest evaporates from the surface. Because of this, the lake has a very long water renewal period: it is estimated that all the water in the lake is renewed within 114 years. Another consequence of the fact that the main losses of water occur due to evaporation, and not runoff, is the increased mineralization of lake water compared to the waters of the rivers flowing into it - the water in the lake is hard and brackish. The waters of the lake are vertically distributed into three layers, which differ in the density of water due to its temperature. The thickness of the upper layer of warm water (epilimnion) varies from 40 to 100 m, reaching a maximum in the cool, windy season (May to September). It is in this layer that the growth of algae occurs, which is the basic element of the entire food pyramid of the lake. The middle layer, the metalimnion, is several degrees cooler than the top layer and extends from its lower edge to 220 m in depth. In the thickness of this layer, vertical movements of biological substances and oxygen dissolved in water occur. The space from the lower level of the metalimnon to the bottom of the lake is occupied by the hypolimnon. The water here is even colder (has the highest density) and has a high concentration of dissolved nitrogen, phosphorus and silicon - products of decomposition of organic matter. This area is almost completely free of dissolved oxygen, and therefore deeper than 220 m the lake is practically devoid of life.

Although these water layers are never completely mixed, a slow exchange of water between adjacent layers does occur. The volume and speed of this exchange depends on the place and time of year. The greatest influx of nutrient-rich water from the metalimnon and hypolimnon to the surface occurs during the cool wind season from May to September, when the westerly wind blows continuously, which local residents called mvera. This wind disturbs the surface of the lake, sometimes causing strong storms, and mixes the water to a considerable depth. In addition to simple mixing, in some places of the lake during this time of year there is a constant transport of deep water to the surface, the so-called upwelling. Due to the peculiarities of the bottom morphology, the upwelling is especially powerful in the southeastern bay of the lake. As a result, during the windy season and for a short time after its end, the highest concentration of plankton is observed here.

Rice. View of Lake Nyasa from Likoma Island.

Tanganyika is a large lake in Central Africa of tectonic origin. The second deepest lake (1435 m) in the world after Lake Baikal (1620 m) and the largest in the world in length (650 km). The water level in the lake depends on the amount of rain that feeds the rivers flowing into the lake. The lake is a drainage lake, the flow occurs through the Lukuga River in the city of Congo. The water temperature in the upper layer fluctuates throughout the year from +23 to +270 C, and at a depth below 400 m it does not change and is +230 C. Lake Tanganyika is distinguished by the uniqueness of its organic world. The lake is exceptionally rich in fish: in total there are about 250 species of fish, and 7 of them are endemic. On the shores of the lake there is a national park where lions, leopards, hippopotamuses, buffalos, antelopes, zebras, chimpanzees and other animals live. The shores of the lake belong to four countries - the Democratic Republic of the Congo, Tanzania, Zambia and Burundi. Lake Tanganyika is located in the deepest tectonic trench of Africa, at an altitude of 773 meters above sea level and is part of the ancient East African Rift system. An underwater threshold divides the lake into two deep-water basins. The lake is part of the Congo River basin, one of the largest rivers peace. The lake was discovered in 1858 by English travelers R. Burton and J. Speke. Coastal landscapes, as a rule, are huge cliffs and only on the eastern side the shores are gentle. On the west coast, the steep side walls of the East African Rift Zone that form the coastline reach 2000 m in height. Coastline dotted with bays and bays. The largest of them is Burton Bay. The lake is fed by several tributaries; the basin area is 231 thousand km2. The largest inflowing river is the Ruzizi, the delta of which is located in the northern part of the lake. From the eastern side, the Malagarasi River flows into the lake. The Malagarasi is older in origin than Tanganyika and in the past flowed directly into the Congo River. The only river that flows out is the Lukuga, which begins in the middle part of the west coast and flows west, connecting with the Zaire River, which flows into the Atlantic. The annual flow of water into the lake is 64.8 km³, of which 40.9 km³ comes from precipitation (63%) and 23.9 km³ from tributaries (37%). A significant share of water consumption is evaporation - 61.2 km³ (94.4%), the volume of flow through the Lukuga is estimated at 3.6 kmі (5.6%). Average surface temperature 25 °C, pH average 8.4. The significant depth of the lake and its location in the tropical zone create conditions under which there is no water circulation in the reservoir, that is, the lake is a meromictic reservoir in which the lower layer of water does not mix with the upper layers. In terms of volume of anoxic waters, Tanganyika ranks second after the Black Sea. It is also likely that at different historical times Tanganyika could have had different inflows and sources from modern ones. The waters of Lake Rukwa could flow into it, and it could flow out into Lake Malawi and the Nile. Due to the lack of water supply, there are concerns that any increase in temperature and evaporation due to climate change could cause the lake's water level to drop extremely quickly.

The lake is divided into three volumetric basins: the Kigoma basin in the northern part with a maximum depth of 1310 meters, the Kungwe basin in the middle with a maximum depth of 885 meters and the Kipili basin in the southern part with a maximum depth of 1410 meters.

Rice. Map of Lake Tangaika

Lake Kivu (area - 2.7 thousand km2, greatest depth - about 500 m) lies north of Lake Tanganyika in the depression of the same western branch of the East African rifts in which Lake Tanganyika lies. The basin of the lake is dammed with lava flows, so the origin of the lake is volcanic-tectonic or zagatno-volcanic. There are active volcanoes on the northern shore of Lake Kivu. During their eruption, powerful lava flows slide into the lake and the water in the lake boils in these places. Unlike other rift lakes, which have predominantly straight shores, Kivu has very winding shores with many picturesque bays and islands. The lake is freshwater, drainage, and the Ruzizi River flows from it, which flows into Lake Tanganyika. It is characterized by an abnormally high temperature of deep waters (+260 C), which is explained by the influence of volcanic activity and the presence of hot springs at the bottom of the lake, and the accumulation of natural flammable gas - methane. Kimvu is a lake in Central Africa, on the border between Rwanda and the Democratic Republic of the Congo in the East African Rift Valley, one of the Great African Lakes.

Rice. Lake Kivu photograph from space

Lake Kivu drains through the Ruzizi River, which flows south into Lake Tanganyika.

Scientists studying a complex mixture of chemical substances, which lies at the bottom of Lake Kivu, cannot give a definite answer - whether the reservoir will remain unchanged for another millennium or whether the gases accumulated under the water will soon break out to the surface. Behind last millennium In the freshwater waters of Lake Kivu, the concentration of carbon dioxide and methane continuously increased. The situation is further complicated by the fact that the region in which the lake is located is seismically dangerous and volcanic activity continues here. Lake Kivu differs in many ways from other bodies of water in both temperate and tropical climates. Its most important feature can be considered the absence of evaporation at the boundary of water and air

Due to the high temperature and humidity of the atmosphere above the lake, a kind of stable “cushion” of hot water vapor is formed between the water and air, which stops the circulation of water molecules. As a result, the liquid does not circulate in the lake, and the gas accumulating at the bottom does not dissolve.

Lake Kivu is naturally fed by warm underwater springs that break through to the surface through a layer of hardened volcanic lava and sedimentary ash.

Periodically, the temperature of these springs changes under the influence of volcanic activity and climatic fluctuations, but this does not affect the overall picture. Under conditions of such stability, the gas accumulating under water is deposited in the form of a compressed layer.

The pressure holding it is also maintained at the same level, but any imbalance will lead to an explosion of the accumulated mixture of methane and carbon dioxide.

Lake Edward (Idi-Amin-Dada) lies north of Lake Kivu. Named after the son of Queen Victoria of England. The area of the lake is 2.15 thousand km2, the greatest depth is 111 meters, the average depth is 17 meters. The lake is located in Central Africa, on the border between Uganda and the Democratic Republic of Congo, a few kilometers south of the equator. The smallest of the Great Lakes of Africa. Named after Edward VII, the eldest son of Queen Victoria, after whom another great lake in Africa, Victoria, was named. The name of the lake was given by Henry Morton Stanley, who visited the lake in 1888. The lake was later renamed Idi Amin Dada in honor of the Ugandan dictator Idi Amin, but today the lake again bears its former name.

The Niamugasani, Ishasha, Rutsuru and Rwindi rivers flow into Lake Edward. Water from the lake flows north through the Semliki River into Lake Albert. Lake Edward is also connected via the Kazinga Canal to Lake George to the northeast. The lake is located at an altitude of 920 m, it is 77 km long and 40 km wide, the surface area of the lake is 2325 km² (15th largest on the continent). The western shore is high and steep, the other shores are flat, marshy, covered with reeds and papyrus. The color of the water in the lake is light green aquamarine, which is associated with a large amount of phytoplankton. The lake is famous for the abundance of birds living on its shores (pelicans, cormorants, gulls, herons, ibises and many others). Herds of antelope and buffalo gather to drink, followed by lions, leopards and hyenas. Almost the entire area around the lake has been declared a nature reserve.

Rice. Lake Edward photographed from space.

Even further north is Lake Albert (Mobutu Sese Seko). Named after the husband of the Queen of England. Discovered in 1864 by the English traveler S.W. Baker. The area of the lake is 5.6 thousand km2, the greatest depth is 58 m. It is a tectonic depression in the northern segment of the Western Rift, which, in turn, is part of the Great African Rift. The lake marks the border between the Democratic Republic of the Congo and Uganda. Albert is famous for the richness and diversity of fish stocks, and its shores for many species of land African fauna. The Semliki rivers (the drainage of Lake Edward) and Victoria Nile (the drainage of Lake Victoria) flow into the lake, and the Albert Nile River, one of the sources of the Nile, flows into the lake. The average annual flow of water into the lake due to precipitation is 4.6 cubic meters. km, due to the runoff from the pool 24.9 cubic meters. km, evaporation is 7.5 cubic meters. km, stock 22 cubic meters. km, water temperature on the surface is up to 30 °C. Rich in fish (over 40 species: Nile perch, tiger fish, etc.). Shipping. The main ports are Butiaba in Uganda and Kasenyi in Congo. Lake Albert is located in the Albertine Rift Valley and is part of a complex system of reservoirs in the upper Nile. The main rivers flowing into the lake are the Victoria Nile of the White Nile system, flowing from Lake Victoria to the southeast through Lake Kyoga, and the Semliki River flowing from Lake Edward, which lies to the southwest. Victoria Nile water contains much less salts than Lake Albert water. The river flowing from Albert in the northernmost part of the lake is called the Albert Nile, which further north becomes the White Nile.

The southern part of the lake, at the confluence of the Semliki River, is swampy. Further to the south stretches the Rwenzori Range, and the Blue Mountains rise above the northwestern coast. There are several villages on the shores of the lake, including the harbors of Butiaba and Kasenyi.

Lake Albert has a shape close to an elongated diamond, reproducing the outlines of the tectonic basin of the northern segment of the Western Rift, which is part of the Great African Rift. In the geographic coordinate system, the lake is oriented from southwest to northeast. Close to this axis, conditionally cutting the surface of the lake into two almost equal parts, lies the state border between the Democratic Republic of the Congo in the west and Uganda in the east. The bottom of the lake, as in most similar depressions, is flat and fairly even. The western edge of the rift in this region reaches 1900-2400 m above sea level. m., or 1300-1800 m above the lake. Eastern edge 1200-1400 m above sea level. m., or about 600-800 m above the lake.

Rice. Physical map of Lake Albert.

Lake Victoria is the largest lake in Africa and the second largest freshwater lake in the world by area after Lake Superior in North America (68 thousand km2). Discovered in 1858 by the English traveler D. Speke. Named after the English Queen Victoria. It is located in a huge flat trough (a trough is an oval-shaped deflection of tectonic origin on the Earth's surface), has relatively shallow depths for tectonic lakes (up to 80 m) and low-lying shores. The upper layer of water in the lake has a temperature of +23 ... +260 C. Numerous islands are scattered throughout the lake, with a total area of 6 thousand km2. Many rivers flow into the lake, including the Kagera - a loop of the Nile; Only one river flows out - the Victoria Nile. The shores of the lake are strongly dissected by bays, bays and peninsulas. In the bays and river mouths there are crocodiles and hippopotamuses, and numerous waterfowl. The lake is rich in fish: in total there are more than 100 species of fish. One of them - Protopterus - is interesting because it is lungfish and has gills and lungs. During the dry season, this fish burrows into the mud and breathes through its gills. The lake is fed mainly by sediments, from which it receives almost 80% of the total influx. In addition, numerous rivers, tributaries and streams flow into it. The average water inflow is 114 km3 regardless of sources. About 16 km3 comes from tributaries, and 98 km3 from precipitation. Annual evaporation from the surface reaches 93 km3. It is believed that over all the years of observation, the amount of water evaporating per year remains virtually unchanged. The average amplitude of lake level fluctuation is 0.3 m, and the maximum annual amplitude of the indicated 45-year observation is 1.74 m. The lake level largely depends on the amount of rain. In recent years they have declined, which is explained, in addition to the general warming of the Earth's climate, also by the destruction of the forests of Africa, and the area around the lake. In 2010, the lake level reached its lowest point in 80 years and is almost one meter lower than in 1990. The lake's water level has been measured since 1896. Its level was recorded in 1906 and 1917, but it remained relatively stable until 1961 of the year.

Rice. Lake Victoria photograph from space

Rice. Lake Victoria and the Great Rift Valley

The relict lakes of Africa are Chad, Tumba, Mai-Ndombe, Ngami. The largest of the relict lakes of the continent is the freshwater (according to some sources, brackish) drainless Lake Chad, located at the southern border of the Sahara Desert in a huge flat basin of the same name. The name of the lake is translated from the language of the local population as “a large expanse of water.” The area of the lake varies from 12 thousand km2 in June-July to 26 thousand km2 in November-December, depending on the amount of precipitation and the full flow of the rivers flowing into it (the main river Shari). Modern Lake Chad is the remains of a huge reservoir with an area of 300-400 thousand km2, which existed in the Pleistocene (for comparison: the area of the Black Sea is 420 thousand km2). The depths of the lake are insignificant (4-11 m). The uniqueness of the lake lies in the fact that the upper layers of the lake are fresh, and the lower layers are salty. This is explained by the fact that salt water is heavy behind fresh water and sinks down. In addition, Chad has an underground drainage along the dry Bahr el-Ghazal channel into the Bodele Basin, so its waters become saltier. In 2006, the lake with an area of 23 thousand km², located on the borders of Nigeria, Niger, Cameroon and the Republic of Chad, shrank 26 times and continues to dry out, which became known thanks to Earth monitoring carried out by the international Disaster Monitoring Constellation system.

The drying up of Lake Chad was also reported by NASA employees who compared space images from 2001 with images taken 38 years ago.

It is known that Chad is drying out for the seventh time in the last millennium. Paleontologists established this from the animal remains found there.

Satellite images taken by Nigeria's first satellite, Nigeria Sat-1, were part of the "The Story of a Dying Lake" exhibition held in Abuja, the capital of Nigeria.

Projects are being developed to transfer part of the flow from the Congo Basin (in particular, Ubangi), from 15 to 100 km per year.

Rice. Satellite image Lake Chad in 2001. Blue - water surface, green - vegetation on the old lake bed. Above are photographs of the lake in 1973, 1987 and 1997.

The relict lakes Tumba and Mai Ndombe (Leopold II) lie in the Congo Basin, Lake Ngami in the Kalahari Basin. The area of Lake Mai-Ndombe (Leopold II) is 2.3 thousand km2, during rains - up to 8.2 thousand km2. The average depth of the lake ranges from 2.5 to 5 m. The shores are low, swampy. A freshwater lake in the western part of the Congo River basin, in the north-west of the Democratic Republic of the Congo. The length is about 130 kilometers. Situated on a swampy lowland. Area -- 2300 sq. km. In the north, the Lotoi River flows into the lake. Like other lakes of the Congo Basin, Mai Ndombe is the remnant of a giant endorheic lake that formed about 1 million years ago. From Lake Mai-Ndombe flow the rivers Lukeni and Kassai, which then flow into the Congo.

In the deserts and semi-deserts of South Africa, unique dry lakes of relict origin, called peni, are common. They are numerous in the sandy Kalahari Desert, where there are about 1000 of them. The bottom of the pens is covered with grass vegetation or bare and composed of lake sediments 2-3 m thick. The pens are rarely filled with water, only during heavy rains. The largest of the penivs, Etosha, is located in the north-west of the Kalahari Desert and is a flat clay basin. During the rainy season, the Etosha Basin becomes a large shallow lake, and after the rains stop, it quickly turns into a swamp.

lake africa geographical

Rice. Peni Etosha

The largest of the mainland's volcanic lakes is Lake Tana, dammed with lava flows, on the Ethiopian Highlands. The area of the lake ranges from 3.1 to 3.6 thousand km2. There are many islands in the lake's waters. Many rivers flow into the lake, but one flows out - the Blue Nile. The lake is rich in fish. The height above sea level is 1830 meters. The lake is fed by four permanent rivers and numerous seasonal tributaries. The average depth is 8 meters, but during dry and wet periods it differs by almost two meters. Depending on the time of year, the surface area of the lake varies from 3000 to 3500 square kilometers.

Fish are found in abundance in Lake Tana. More than 10,000 tons of fish are caught during the year. The diversity of birds is also great, they live both in coastal areas and on the islands.

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Kivu

The area of Kivu is 2700 km². The maximum length of the lake is 89 km, width is 48 km. The average depth of the lake is about 240 meters, and the maximum depth exceeds 480 meters. The lake was formed as a result of volcanic activity. The water in Kivu is fresh. The coastline of the reservoir is indented, there are a lot of islands, the largest of which is called Idjvi. The lake is potential, as it contains methane deposits. Despite this, the shores are densely populated. People catch telapia, sardines, carp and catfish there. The Nyungwe, Kahuzi-Biega and Virunga Forest national parks are home to chimpanzees, antelope, buffalo and. Pelicans, ibises and gulls nest along the banks overgrown with bamboo and papyrus. The lake is shared between the Democratic Republic of the Congo and Rwanda.

Tana

Tana covers an area of 3000 to 3500 km². The maximum length of the lake is 84 km, width is 66 km. The maximum depth during the rainy season does not exceed 15 meters. The lake was formed as a result of volcanic activity that blocked the flow of inflowing rivers about 5 million years ago. It was originally much larger than it is today. Tana is a freshwater lake. The Blue Nile originates from it. Due to the gradual decline in water levels, the shores of the lake become swampy, becoming home to aquatic birds such as ducks, geese and pelicans. Local residents make money by catching fish, which is found here in abundance. The lake is located in Ethiopia.

Bangweulu

The surface area of permanently open water is approximately 3,000 km², and expands significantly when marshes and floodplains overflow their banks at the end of the rainy season in May. The total area of the lake and wetlands reaches 15,000 km². The average depth of Bangweulu does not exceed four meters. This freshwater lake is of tectonic origin. Thanks to the swampy shore, a unique and unique river has been preserved here in its original form. Crocodiles also live in the thickets of sedge and papyrus. Indigenous people catches catfish, bream and yellowbelly in the lake. Bangweulu is located in Zambia.

Mweru

The area of the lake is 5120 km². The maximum length of the lake is 131 km, width - 56 km. The average depth does not exceed seven meters, and the maximum depth is about 20-27 meters. Fresh water filled the tectonic depression, shaped like a heart. Mweru is part of the Congo River system. Thanks to this, the lake level does not depend on weather changes and drought. Lumangwe Falls and Lusenga Plain National Park are of interest to tourists. The lake is located on the territory of two African states: Zambia and the Democratic Republic of the Congo.

Albert

The area of the lake is 5300 km². The maximum length of the lake is 160 km, width - 30 km. The average depth is 20 meters, the maximum depth does not exceed 60 meters. The reservoir is located in a tectonic depression. Throughout the year, the water in Alberta remains warm. Thanks to this, the ichthyofauna is well developed here. Part of the coastline is represented by cliffs and ledges from which hot springs flow. The flat areas are covered. In some places the shores turn into wetlands, a favorite habitat of crocodiles and other dangerous creatures. Lake Albert is located in the Democratic Republic of the Congo and Uganda.

Rudolf

The area of the lake is 6405 km². The maximum length of the lake is 290 km, width - 32 km. The average depth does not exceed 30 meters, and the maximum reaches 109 meters. The water is brackish. Three adjacent islands are national parks. The tribes living on the sandy shores are engaged exclusively in fishing. Due to the arid climate, animals and vegetable world around the lake is relatively sparse. The lake is known for the large number of animals that live on its shores. The reservoir is located in Kenya and Ethiopia.

Chad

Historically, Lake Chad ranks among the largest lakes in Africa, although its surface area varies greatly depending on the season and also from year to year. Previously, the area of the lake reached about 17,800 km², however, at the beginning of the 21st century it decreased to approximately 1,500 km². The average depth of the lake is 1.5 meters, the greatest depth is 11 meters. Lake Chad was formed due to depression in the earth's crust. The coastal line is swampy. There are many islands in the northeastern part. The northern border is dunes. Tropical plants grow in the south. The waters of Lake Chad contain a lot of algae, which are a source of food for fish. The floating islands are home to hippos, crocodiles and waterfowl. Hyenas also come to the shores to drink. Residents, in addition to fishing, are engaged in the extraction of caustic salt. The reservoir is located in Nigeria, Cameroon, Chad and Niger.

Nyasa

The area of Nyansa is 29,604 km². The maximum length of the lake is 560 km, width - 75 km. The average depth is 292 meters, the maximum depth is 706 meters. The lake is considered one of the deepest on Earth. It was formed at the site of a tectonic fault. The coastline is amazingly diverse. There are rocky shores, bays, sandbanks and river deltas. There are 1,000 species of fish in the lake, many of which live at great depths. The abundance of ichthyofauna attracts birds such as eagles, herons and cormorants. Large animals are represented mainly by hippopotamuses and crocodiles. Lake Nyansa is located in the following African countries: Malawi, Mozambique and Tanzania.

Tanganyika

The area of the lake is 32900 km². The maximum length of the lake is 673 km, width - 72 km. The average depth is 570 meters, the greatest depth is 1470 meters. The reservoir is located in a tectonic depression. Over the 10 million years of its existence, the lake has never dried up, so there is a unique undersea world. The coastline has a rocky landscape. In the east it is represented by a flat strip. Tanganyika is associated with birds, amphibians and waterfowl. Millions of people live along the shores of the lake, so shipping is developed on it. Tanganyika is located in Tanzania, Zambia and the Democratic Republic of Congo.

Victoria

Victoria is the largest freshwater lake on the African continent, and covers an area of approximately 68,800 km². The maximum length of the lake is 337 km, width - 250 km. The average depth is 40 meters, the greatest depth is 83 meters. The coastline is low and flat. In the north the land is covered with savannas, and in the west with equatorial forests. The lake is home to 200 species of fish. The adjacent forests are home to lizards, exotic birds, porcupines and mongooses. Rubondo Island Nature Reserve is a gem for tourists. The main threats to Lake Victoria include the proliferation of water lilies. The lake is found in Tanzania, Kenya and Uganda.

Map of the location of the largest lakes in Africa

Blood Lake of Africa January 1st, 2017

An airplane casts a shadow on the bright red surface of Lake Natron in Tanzania. Photo by: George Steinmetz.

Lake Natron is a salt lake located in the vast African Great Rift Valley - in northern Tanzania, near the border with Kenya and just northeast of the Ngorongoro Crater. Hidden between volcanic hills and deep craters, Lake Natron lies at the lowest point of the rift valley - 600 meters above sea level - and is perhaps the most alkaline body of water in the world.

Is it possible to swim in such a lake and is there life there?

But just for contrast, here is another wetland in Africa.

Lake Natron is translated as “red” because of its special color, which is given to it by certain microorganisms that appear when the level of salinity and alkalinity increases excessively. The main such organism is cyanobacteria, a tiny bacterium that, like plants, absorbs light through photosynthesis. As a result, the accumulated photons cause a change in the pigmentation of this amazing bacterium towards a red color and millions of bacteria of the cyano species formed in the alkali of Lake Natron give a deep red color to all surfaces of the water. Only in shallow waters, where there are few of these bacteria less water It is no longer bright red, but orange.

This is truly a miracle canvas of nature painted by a local God named Lengai, the progenitor of all things on Earth among the Maasai tribes.

The total area of the reserve is 700 square meters. km.

Swimming in Lake Natron is not recommended. Any contact with alkaline water can result in burns and blistering of the skin - it is better not to risk it. However, from one glance at the skeletons of animals and birds and their limestone mummies scattered around the lake, it will become clear that it is better not to get close to Natron.

Such discomfort is most often justified by what is seen. It is here, not far from this “dead sea” of Tanzania, that one of the sacred places is located Ancient Africa- Ol Doinyo Lengai volcano, which translated from the Maasai language means “Mountain of the Gods” or “Mountain of Spirits”. This volcano today is one of the “LIVING WONDERS OF TANZANIA”, more about which you can read in the fascinating article “Why don’t the volcanoes of Tanzania sleep?”

According to some sources, Ol Doinyo Lengai in last time I woke up in October 2008 and never fell asleep. According to the most recent data, a volcanic eruption was observed in 2010, which was apparently caused by the growing discontent of the “gods living in the crater of the volcano.”

One of the main reasons for their dissatisfaction could be the active discussion of the construction of a soda processing plant on the shores of Lake Natron - right at the foot of Ol Doinyo Lengai. The second reason could be plans to build a hydroelectric power station at the northern end of the lake, which would provoke a change in the alkaline balance in the lake.

Be that as it may, the Lake Natron reserve, which includes the sacred mountain, is increasingly exposed to external influence from large companies, which disturbs the peace zone and can provoke, according to shamans from the Masai tribe, the “wrath of the gods” Ol Donyo Lengai.

Lake Natron in Tanzania is fed by the Iwaso Nyiro River ("River of Brown Water" in the Samburu language) and mineral-rich hot springs.

With strong evaporation, a crust of alkaline salt forms on the surface of the lake, which is also often colored red or pink as a result of the activity of microorganisms living in the lake.

As water evaporates during the dry season, the salinity of the lake increases to the point where the salt-loving microorganisms living in it begin to multiply wildly.

These organisms that live in high salinity conditions - halophilic cyanobacteria - have the ability to photosynthesize, just like plants. During the process of photosynthesis, a red pigment is released, which gives the bright red color. deep water and orange is smaller.

And the lake is the only breeding area for the 2.5 million endangered Lesser Flamingos that live in the valley.

These flamingos flock along salt lakes in the area where they feed on Spirulina (blue-green algae with red pigments). Lake Natron is the only breeding site for the Lesser Flamingo because its caustic environment is a kind of barrier against predators trying to get to the nests of these birds.

Temperatures in wetlands can reach 50 degrees Celsius (120 degrees Fahrenheit), and depending on rainfall, alkalinity can reach a pH of 9 to 10.5 (almost as alkaline as ammonia).

In 1962, due to heavy rains, there was a flood. According to experts, more than a million eggs were destroyed.

Threats to the salinity balance from increased freshwater inflows come from the engineered loading watersheds of Lake Natron and the planned operation of a hydroelectric dam. Although development plans include building a dam at the northern end of the lake to contain fresh water, the threat of dissolution is still serious.

A new threat to Lake Natron is the development of a soda processing plant on the shores of the lake. The plant pumps water out of the lake and then chemical processes extracts sodium carbonate to convert it into laundry detergent for export. Housing was also built near the plant for more than 1,000 workers, and coal was brought in for the power plant to provide energy for the entire plant complex.

Because of its unique biological diversity, Tanzania named the Lake Natron Basin to the Ramsar List of Wetlands of International Importance on 4 July 2001.

The hunting grounds within the Lake Natron Wildlife Refuge are located on its northern and southern boundaries and are called, respectively, the Lake Natron South Game Control Area and the Lake Natron North Game Control Area.

The southern hunting grounds of the reserve are located north of Arusha in the famous Masai Steppe Maasai Steppe), stretching over 1500 sq. km. To the west they border with the Ngorongoro Conservation Zone, and to the north and east with Kenya and Lake Natron, respectively. These areas are home to two permanent luxury campsites and two adventure fly camps. The Kiserian adventure camp offers accommodation in a valley with stunning views of Mount Kilimanjaro and excellent hunting opportunities for Grant's and Thompson's gazelle and, in the very north of the protected area, for gerenuk and lesser kudu.

An equally wonderful place to observe the life of the Maasai lands is the luxury camping “Kitumbeine luxury base camp”, located near Mount Kitumbeine of the same name (2800 meters), where savannah acacias grow. The camp is located at the foot of this mountain and offers indescribably beautiful panoramas overlooking the mountain ranges of the Great Rift Rift and the white smoking cap of the still active Olduvai volcano. It has some of the best hunting grounds for oryx, mountain buffalo and large leopard.

The northern hunting grounds (Lake Natron North Game Control Area) 0 are much more extensive. They run along the border of Tanzania and Kenya, east of Lake Natron itself, where the Great Rift Rift mountain ranges rise, covered with a dense massif of mixed tropical forest, where they were preserved in large quantities Mountain buffalos are a special trophy of Masailand. You can stay in one of two mobile hunting camps, which will be delivered along with provisions by plane from Arusha or Kilimanjaro.

Here the terrain is wilder and untrodden by humans than in the south. That is why the villages are original African tribe The Maasai here seem to fit particularly seamlessly into the landscape of the Lake Natron Nature Reserve. These are some of the best places for photo safari. Just imagine the red surface of water with the same red haze in which thousands of small flamingos are drowning on the horizon, as if involuntarily coloring their wings in orange and pink shades.

Here it is allowed to hunt typical representatives of Masailand fauna: mountain buffalo (buffalo), bushpig or warthog, leopard, lion, hyena, jackal, white antelope, savannah zebra, small cats (caracal, genetta, civet, serval and wild cat), small antelopes (dik-dik, duiker and Steinbeck antelope), medium-sized antelopes (gerenuk, lesser kudu, East African bushbuck, impala) and gazelles of Thompson, Grant, Robert and mountain readbook.

Name	Greatest depth (in meters)	Height above sea level (in meters)
Victoria			Tanzania, Kenya, Uganda
Tanganyika			Tanzania, Zambia, Congo, Burundi
			Tanzania, Mozambique, Malawi
			Chad, Cameroon, Nigeria, Niger
			Kenya, Ethiopia
Mobutu-Sese-Seko			Uganda, Congo
			Zambia, Congo
Bangweulu

			Rwanda, Congo
			Uganda, Congo

Based on the origin of the lake basin in Africa, there are 3 types of lakes: 1) tectonic, 2) relict, 3) volcanic.

The lakes of East Africa are for the most part of tectonic origin. The Great Lakes are created by the Great Rifts. Most of these lakes lie at the bottom of rift basins, which began to fill with water almost from the moment of their origin (or, more precisely, their revival as a result of recent movements of the earth’s crust). Among the rift lakes there are large and small, deep and shallow, fresh and salty. But almost all of them have a characteristic elongated shape, determined by the outlines of the rifts themselves. As a rule, lakes are located in fault depressions (grabens) in a row, one after another, forming long chains or garlands. The first thing that catches your eye when looking at the physical map of East Africa is the unique chain of large lakes, starting in the south with Nyasa and continuing with the Western Rift lakes - Rukwa, Tanganyika, Kivu, Edward and Albert. Another lake garland is located on the territory of the Eastern Rift and its spurs; Here, however, there is only one large lake - Rudolf, but there are many small ones. Mveru stands somewhat apart among the lakes of fault origin: it occupies an independent graben, which is believed to be a side branch of the Western Rift, but has no direct connection with it in the modern topography. Almost all large lakes in Africa lie in deep rift basins (grandiose faults in the earth's crust) on the East African Plateau and are classified as tectonic (Tanganyika, Nyasa, Edward, Albert, Kyoga, Mweru Rudolf, Victoria). Most of them are deep and bordered by steep slopes. Basins of lakes Tanganyika and Nyasa. Tectonic and volcanic processes in East Africa did not occur simultaneously, but over a very long period. It is therefore natural that East African lakes have different ages. Among them there are “old people”, formed millions of years ago, there are also “young people”, whose age is measured “only” in thousands of years (and in some small lakes - hundreds and even tens of years). Almost all large lakes are considered “old people”. They have undergone a long and complex evolution. Their level and outlines changed repeatedly depending on the movements of the earth's crust and climate fluctuations, primarily moisture conditions. During eras of humid climates, the size of the lakes increased, and some bodies of water now isolated from each other merged together. On the contrary, during dry periods the area of lakes was greatly reduced, and many of them dried up altogether. All these and other features of their history left a noticeable imprint on the modern appearance of lake basins and the lakes themselves, and had a strong influence on the development of life in lake waters.

The fourth and final group can include numerous lakes that do not drain into the ocean. These are, firstly, all the lake reservoirs of the Eastern Rift from Lake Rudolf in the north to Lake Manyara in the south; secondly, Lake Rukwa in the southern branch of the Western Rift; thirdly, Lake Shirva in one of the side spurs of the Nyasa rift. Unlike the lakes of the three previous groups, in which the water is fresh (only in Kivu it is brackish), the reservoirs of the fourth group are mostly salty. In addition to those listed, there are other closed lakes in East Africa (for example, many crater lakes), but they are all insignificant in size and are not of particular interest to us now.

Nyasa is a tectonic lake formed as a result of a fracture in the earth's crust. A depression is a depression in the earth's surface, the bottom of which lies below ocean level, crypto is a prefix to the name of the structure, denoting its thin appearance. The third largest lake in area and the southernmost of the lakes of the Great Rift Valley in East Africa, which fills a deep depression in the earth's crust between Malawi, Mozambique and Tanzania. The lake runs from north to south, length is 560 km, depth is 706 m. It is the ninth largest and third deepest (after Baikal and Tanganyika) among freshwater reservoirs in the world. It contains 7% of the world's liquid fresh water and creates the most diverse lake ecosystem in terms of the number of species, most of which are endemic.

Rice.

Although these water layers are never completely mixed, a slow exchange of water between adjacent layers does occur. The volume and speed of this exchange depends on the place and time of year. The greatest influx of nutrient-rich water from the metalimnon and hypolimnon to the surface occurs during the cool windy season from May to September, when the westerly wind, locally called mwera, blows continuously. This wind disturbs the surface of the lake, sometimes causing strong storms, and mixes the water to a considerable depth. In addition to simple mixing, in some places of the lake during this time of year there is a constant transport of deep water to the surface, the so-called upwelling. Due to the peculiarities of the bottom morphology, the upwelling is especially powerful in the southeastern bay of the lake. As a result, during the windy season and for a short time after its end, the highest concentration of plankton is observed here.

Rice.

Tanganyika is a large lake in Central Africa of tectonic origin. The second deepest lake (1435 m) in the world after Lake Baikal (1620 m) and the largest in the world in length (650 km). The water level in the lake depends on the amount of rain that feeds the rivers flowing into the lake. The lake is a drainage lake, the flow occurs through the Lukuga River in the city of Congo. The water temperature in the upper layer fluctuates throughout the year from +23 to +270 C, and at a depth below 400 m it does not change and is +230 C. Lake Tanganyika is distinguished by the uniqueness of its organic world. The lake is exceptionally rich in fish: in total there are about 250 species of fish, and 7 of them are endemic. On the shores of the lake there is a national park where lions, leopards, hippopotamuses, buffalos, antelopes, zebras, chimpanzees and other animals live. The shores of the lake belong to four countries - the Democratic Republic of the Congo, Tanzania, Zambia and Burundi. Lake Tanganyika is located in the deepest tectonic trench of Africa, at an altitude of 773 meters above sea level and is part of the ancient East African Rift system. An underwater threshold divides the lake into two deep-water basins. The lake is part of the Congo River basin, one of the largest rivers in the world. The lake was discovered in 1858 by English travelers R. Burton and J. Speke. Coastal landscapes, as a rule, are huge cliffs and only on the eastern side the shores are gentle. On the west coast, the steep side walls of the East African Rift Zone that form the coastline reach 2000 m in height. The coastline is dotted with bays and bays. The largest of them is Burton Bay. The lake is fed by several tributaries; the basin area is 231 thousand km2. The largest inflowing river is the Ruzizi, the delta of which is located in the northern part of the lake. From the eastern side, the Malagarasi River flows into the lake. The Malagarasi is older in origin than Tanganyika and in the past flowed directly into the Congo River. The only river that flows out is the Lukuga, which begins in the middle part of the west coast and flows west, connecting with the Zaire River, which flows into the Atlantic. The annual flow of water into the lake is 64.8 km³, of which 40.9 km³ comes from precipitation (63%) and 23.9 km³ from tributaries (37%). A significant share of water consumption is evaporation - 61.2 km³ (94.4%), the volume of flow through the Lukuga is estimated at 3.6 kmі (5.6%). Average surface temperature 25 °C, pH average 8.4. The significant depth of the lake and its location in the tropical zone create conditions under which there is no water circulation in the reservoir, that is, the lake is a meromictic reservoir in which the lower layer of water does not mix with the upper layers. In terms of volume of anoxic waters, Tanganyika ranks second after the Black Sea. It is also likely that at different historical times Tanganyika could have had different inflows and sources from modern ones. The waters of Lake Rukwa could flow into it, and it could flow out into Lake Malawi and the Nile. Due to the lack of water supply, there are concerns that any increase in temperature and evaporation due to climate change could cause the lake's water level to drop extremely quickly.

Rice.

Lake Kivu drains through the Ruzizi River, which flows south into Lake Tanganyika.

Scientists studying the complex mixture of chemicals lying at the bottom of Lake Kivu cannot give a definite answer - whether the reservoir will remain unchanged for another millennium or whether the gases accumulated under the water will soon break out to the surface. Over the past millennium, the concentrations of carbon dioxide and methane in the freshwater waters of Lake Kivu have steadily increased. The situation is further complicated by the fact that the region in which the lake is located is seismically dangerous and volcanic activity continues here. Lake Kivu differs in many ways from other bodies of water in both temperate and tropical climates. Its most important feature can be considered the absence of evaporation at the boundary of water and air

Lake Kivu is naturally fed by warm underwater springs that break through to the surface through a layer of hardened volcanic lava and sedimentary ash.

The pressure holding it is also maintained at the same level, but any imbalance will lead to an explosion of the accumulated mixture of methane and carbon dioxide.

Rice.

Rice.

The drying up of Lake Chad was also reported by NASA employees who compared space images from 2001 with images taken 38 years ago.

It is known that Chad is drying out for the seventh time in the last millennium. Paleontologists established this from the animal remains found there.

Satellite images taken by Nigeria's first satellite, Nigeria Sat-1, were part of the "The Story of a Dying Lake" exhibition held in Abuja, the capital of Nigeria.

Projects are being developed to transfer part of the flow from the Congo Basin (in particular, Ubangi), from 15 to 100 km per year.

Rice.

lake africa geographical

Rice.

Fish are found in abundance in Lake Tana. More than 10,000 tons of fish are caught during the year. The diversity of birds is also great, they live both in coastal areas and on the islands.

Name	Area km sq	Maximum depth m
Victoria lake
Tanganyika lake
Nyasa lake
Chad lake
Rudolph Lake
Albert (Mobutu-Sese-Seko) lake
Mveru lake
Bangweulu lake
Tana lake
Kivu lake
Kyoga lake
Rukwa lake
Mai-Ndombe lake
Edward Lake

Lakes of Africa. Great lakes of Africa. The deepest lake in Africa. Tanganyika is the deepest lake in Africa

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Map of the location of the largest lakes in Africa