Tectonic lakes. Large lakes

The uniqueness of the natural lakes lies in a number of their special characteristics. It is inherent in slow water exchange, free thermal regime, a kind of chemical composition, water levels.

In addition, they create their microclimate and cause changes in the adjacent landscape. Mineral and organic substances are accumulated in them, some of them have value and utility.

Geographical object "Lake" (value)

There are about 5,000,000 lakes in our world. Lakes on the globe occupy almost 2% of the surface, and this is almost 2.6 million km 3. As a component of the hydrosphere, classical natural lakes, are water bodies of natural origin, which are lake bowls with water, which do not have direct contact (contact) with the sea or ocean. There is a whole science that is engaged in their study - Limnology. However, there are also anthropogenic lakes that arose as a result of human activity.

If we consider the lake, as geographical object, then his definition becomes clearer: it is a pit on land with closed edges, into which flowing water falls and as a result, it accumulates there.

Characteristic of lakes

To give a specific lake accurate characteristic, you need to decide on its origin, the position (above or underground), the type of water balance (waste or not), the parameters of mineralization (fresh or not), its chemical composition, etc.

In addition, you need to accurately determine the following parameters: the total area of \u200b\u200bthe aqueous mirror, the total length of the coastline, the maximum distance between opposite shores, the average width of the lake (calculated by dividing the area to the previous indicator), the volume of water, which fills it, its average and maximum depth .

Types of lakes by origin

Generally accepted classification of lakes on the factor of origin Next:

1. Anthropogenic (artificial) - created by man;
2. Natural - originally emerged (exogenous or endogenous - or from the inside of the Earth, or as a result of processes on its surface), without human intervention.

Natural lakes in turn have their own division on the principle of origin:

• Tectonic - the cracks arising for one or another in the earth's crust are filled with water. Most. famous lake This type is Baikal.
• The glacier - the glacier melts and the resulting water creates a lake in the cloth of the glacier himself or any other. Such lakes, for example, in Karelia and Finland: lakes appeared on the trajectory of the glacier in the tectonic cracks.
• Staritsa, Lagoon or Liman - a decrease in the water level cuts off part of the river or ocean.
• Karst, suffosionic, thermocarbon, eoloid - leaching, drawdown, pulling, blowing, respectively, create a deepening, which is filled with water.
• The hub lake occurs when the collapse or earthquake is cut off with a jumper sushi part of the water stroke from the main water object.
• In the mountain basins and craters of volcanoes or channels of their eruption, water is often going to water.
• Other.

The value of lakes in nature and for humans

The lakes are natural water tanks that can adjust the river stock: take excess water and, on the contrary, to give them part with a general decrease in the water level in the river. A large aqueous aqueous mass of thermal inertia, the action of which can significantly soften the climate of nearby territories.

Lakes are an important object for fishing, salt mining, waterways. Water from the lakes are often used for water supply. Ponds can be used to organize the power reservoir of water installations. Of them mining sapropels. Some lake dirt possess therapeutic properties and are used in medicine. The importance of lakes in the planet ecosystem is difficult to overestimate, they are an organic element of the entire natural mechanism.

The biggest lakes in the world

Among the lakes there are two main recordsman:

The Caspian Sea is the largest area (376000 km 2), but relatively not deep (30 m);

(Lake Baikal)

Baikal - a record of depth (1620 meters!).

The average majority record holders in lake brethren are tectonic lakes.

- The reservoir formed on the sushi surface in natural recess. Since the lake does not have a direct connection with the ocean, it is a reservoir of slow water exchange.

Total area of \u200b\u200blakes on globe - About 2.7 million km 3, which is 1.8% of the sushi surface.

The main characteristics of the lake:

• lake Square - water mirror area;
• shore Line - Water cut length;
• lake length - The shortest distance between the two coastline dots are most remote from each other, average width -square ratio to length;
• lake volume - the volume of the basin filled with water;
• medium depth - The ratio of the volume of the water mass to the square;
• maximum depth - Located direct dimensions.

The largest area of \u200b\u200bthe water surface of the lake on Earth - Caspian (376 thousand km 2 at a water level of 28 m), and the deepest Baikal (1620 m).

The characteristics of the largest lakes of the world are given in Table. one.

In each lake, three interrelated components are distinguished: basin, water mass, vegetation and animal world of the reservoir.

Lake Mira

By Regulation The lakeside of the lake is divided into terrestrial and underground. The latter are sometimes filled with juvenile water. The underground lakes can be attributed to both a treated lake in Antarctica.

Lake Basins may be as endogenic, so I. Exogenous Origin that most significantly reflected on their size, form, water mode.

The largest lake basins. They can be located in tectonic slides (Ilmen), in the foothill and intergoregous deflections, in rabes (Baikal, Nyasa, Tanganic). Most of the major lakes Kotlovin have a complex tectonic origin, both discontinuous and folded movements (Issyk-Kul, Balkhash, Victoria, etc.) are involved in their formation. All tectonic lakes are distinguished by large sizes, and most - and considerable depths, steep rocky slopes. The bottom of many deep lakes Les below the world's ocean level, and the ox mirror is higher than the level. In the location of the tectonic lakes, certain patterns are observed: they are focused along the strucks of the earth's crust or in rhypsic zones (Syrian-African, Baikal), or framed by the spikes: along the Canadian spit settle down a large Bear lake, Big slave, great north-American lakes, along the Baltic Shield - Onega, Ladoga, etc.

Name of Lake	Maximum surface area, thousand km 2	Height above sea level, m	Maximum depth, m
Caspian Sea
				North America
Victoria
				North America
				North America
Aral Sea
Tanganyika
Nyasa (Malawi)
Big bear				North America
Big slave				North America
				North America
Winnipeg				North America
				North America
Ladogian
Maracaibo				South America
Bangveulu
Onega
Tonlesep
Nicaragua				North America
Titicaca				South America
Athasta				North America
				North America
Issyk-Kul.
Big salty				North America
				Australia

Volcanic lakes occupy crater and caldera extinct volcanoes (Cracker Lake on Kamchatka, Lake Java, New Zealand).

Along with the lake hollows created by the internal processes of the Earth, the lake baths formed at the expense of exogenous processes.

Among them are the most common glacier Lakes on the plains and in the mountains, both in the brands, filled with a glacier and in lowering between the hills in the non-uniform sediments of the Moraine. The destructive activities of the ancient glaciers are obliged to their origin of Lake Karelia and Finland, which are elongated towards the movement of the glacier from the North-West to the southeast along the tectonic cracks. Actually mixed glacial and tectonic origin have Ladoga, Onega and other lakes. To the glacial hooks in the mountains include numerous, but small Karkov Lakes located in a bowl-shaped deepening on the slopes of the mountains below the snow border (in the Alps, in the Caucasus, Altai), and tigal Lakes - in the trough-shaped glacial valleys in the mountains.

With uneven accumulation of glacial sediments on the plains, lakes among hilly and sea relief are connected: in the north-west of the Eastern European Plain, especially at Valdai Hills, in Baltic States, Poland, Germany, Canada and in the north of the United States. These lakes are usually shallow, wide, with blade shores, with the islands (Seliger, Valdai et al.). In the mountains, such lakes arose on the site of the former languages \u200b\u200bof glaciers (Como, Garda, Vurm in the Alps). In the areas of ancient glaciation, the lakes in the hollows of the flow of melted glacial waters, they are elongated, trough-shaped, usually small and shallow (for example, a long, round-near Moscow).

Karst Lakes are formed in places of leaching of rocks underground and partly surface waters. They are deep, but small, often rounded in shape (in the Crimea, in the Caucasus, in Dinar and Other Mountains).

Suffosionic The lakes are formed in the hollows of sediments at the place of intense removal by the underground waters of small-seed and mineral particles (south Western Siberia.).

Term Carts The lakes occur when the multi-member soil or pulling ice is groaning. Thanks to them, the Kolyma lowland is one of the most lake edges of Russia. Many relic thermal lakes Kotlovin are located in the north-west of the Eastern European Plain in the former arrival zone.

Eoloic Lakes arise in the pitual blowing (lake Tecca in Kazakhstan).

Predaruds The lakes are formed in the mountains, often after earthquakes, as a result of collaps and landslides, brave river valleys (Lake Sarrebskoy in the Murgab Valley on the Pamir).

In the valleys of the plain rivers, the numerous lakes of the characteristic horseshoe-shaped form resulting from messenger of rivers and the subsequent hidden rigging; When drying rivers in Bococham - River lakes are formed; In the delta rivers - small Lakes-Ilmena, at the place of the ducts, often shouted with reed and reeds (Ilymeni Volzhsky delta, Lake Kuban smashes).

On the low-lying coasts of the seas, coastal lakes are characterized in the place of Limanov and Lagoon, if the latter are separated from the sea with sandwheel jumpers: braids, bars.

Special type includes Organogenic Lakes among swamps and coral buildings.

These are the main genetic types of lake kitelin, due to natural processes. Their location is presented in Table. 2. But recently there is more and more "man-made" lakes created by a person - gas-called anthropogenic lakes: lakes - reservoirs on rivers, lakes - ponds in quarries, in salt specks, on the site of peatores.

By Genesis of water masses Allocate two types of lakes. Some have water atmospheric origin: precipitation, river and groundwater. Such lakes freshAlthough in a dry climate ultimately can become salty.

Other lakes were part of the World Ocean - these are relic Salt Lakes (Caspian, Aralskoe). But in such lakes, primary seawater can be strongly transformed and even completely displaced and replaced by atmospheric waters (Ladoga et al.).

Table 2. Distribution of the main genetic groups of lakes on the continents and parts of the world

Genetic groups of lakes	Continents and parts of light
	Western Europe	Foreign Asia	North America	South America		Australia
Glacier
Glacial and tectonic
Tectonic
Volcanic
Karst
Residual
Lagunny
Floodplain

In action From water balance, so on. Under the conditions of the tributary and flow, the lakes are divided into the waste and faceless. Lakes throwing part of its waters in the form of a river flow - waste;a special case of them are Flowing lakes. Many rivers can fall into the lake, but only one (hangar from Lake Baikal, Neva from Ladoga Lake and etc.). Lakes, not having a runoff in the world ocean - Cleanless (Caspian, Aral, large salty). The water level in such lakes is subject to vibrations of different duration, which is due primarily by perennial and seasonal changes in climate. In this case, the morphometric characteristics of the lakes and the properties of the aquatic masses are changed. This is especially noticeable on lakes in arid areas, which are prompted by long-term wet wetting cycles and climate aridness.

Water lakes, like others natural waterscharacterized by various chemical composition and varying degrees of mineralization.

In the composition of the salts in the water of the lake are divided into three types: carbonate, sulfate, chloride.

By Mineralization degree Lakes are divided by fresh(less than 1% o), Solonishy (1-24.7% C), Salt (24.7-47% O) and Mineral (more than 47% C). An example of a fresh lake can serve as a Baikal, the salinity of whose will is 0.1% C \\ Solonish - Caspian Morse - 12-13% Oh, a large salt - 137-300% Oh, the Dead Sea - 260-270% Oh, in some years - up to 310% s.

In the distribution of lakes with varying degrees of mineralization on the earth's surface, geographical zonality is traced due to the moisture coefficient. In addition, those lakes in which rivers flow are distinguished by low salinity.

However, the degree of mineralization may be different and within one lake. So, for example, in a blind-eyed lake Balkhash, located in the arid zone, in the western part, where r. Or, the water is fresh, and in the eastern part, which is connected to the western only narrow (4 km) shallow strait, saltwater water.

In the oversaturation of the lakes from the pickle of the salt, they begin to fall into the precipitate, their crystallization occurs. Such mineral lakes called self-making (for example, Elton, Baskunchak). Mineral lakes in which lamellar fine needles are deposited, are known as mud.

An important role in the life of the lakes plays Thermal regime.

Fresh lakes of hot heat belt are characterized by the most warm water At the surface, with depth it gradually decreases. Such a temperature distribution in depth is called direct thermal stratification. The lakes of the cold thermal belt almost all year have the coldest (about 0 ° C) and light water at the top; With depth, the water temperature rises (up to 4 ° C), water becomes more denser, harder. Such a temperature distribution in depth is called inverse thermal stratification. The lakes of a moderate heat belt have variable stratification by season of the year: in the summer straight, in winter is reverse. In the spring and autumn there are such moments when the temperature vertically is the same (4 ° C) at different depths. The phenomenon of constancy temperature in depth is called Homoterma (Spring and autumn).

An annual thermal cycle in the lakes of a moderate belt is divided into four periods: spring heating (from 0 to 4 ° C) is carried out due to convective mixing; summer heating (from 4 ° C to maximum temperature) - by molecular thermal conductivity; Autumn cooling (from the maximum temperature to 4 ° C) - by convective mixing; Winter cooling (from 4 to about ° C) - again by molecular thermal conductivity.

In the winter period of freezing lakes, the same three phases are distinguished as the rivers: freezing, ice station, autopsy. The process of formation and melting ice is similar to rivers. Lakes, as a rule, for 2-3 weeks are covered with ice than rivers in the region. The thermal mode of freezing salted lakes resembles the mode of the seas and oceans.

Dynamic phenomena in the lakes include trends, unrest and sewage. Stock trends arise when the river shoves in the lake and outflow of water from the lake to the river. In the flow lakes, they can be traced throughout the water area of \u200b\u200bthe lake, in the continuing - in areas adjacent to the mouth or the source of the river.

The height of the waves on the lake is less, but the steepness is greater compared to the seas and oceans.

The movement of water in the lakes, along with dense convection, contributes to the mixing of water, the penetration of oxygen into the lower layers, the uniform distribution of nutrients, which is important for the very diverse inhabitants of the lakes.

By Nutritional properties of water mass And the conditions for the development of the life of the lake are divided into three biological types: olitrophic, eutrophic, dystrophic.

Oligotrophic - Malopian lakes. These are large deep transparent lakes with greenish-blue water rich in oxygen, so organic residues are intensively mineralized. Because of the small number of biogenic elements, they are poor plankton. Life is rich, but there is a fish, crustaceans. This is many mountain lakes, Baikal, Geneva, etc.

Eutrophic Lakes have a large supply of nutrients, especially nitrogen and phosphorus compounds, shallow (up to 1015 m), well warmed, with brown-green water. The oxygen content decreases with depth, because of which the fishes and other animals are wintering. The bottom is peat or or etched with an abundance of organic residues. In summer, there is a "flowering" of water due to the strong development of phytoplankton. In the lakes rich vegetable and animal world. They are most common in the zones of the forest-steppe and steppes.

Dystrophic Lakes are poor nutrients and oxygen, they are shallow. The water in them is acidic, low-transparent, brown due to the abundance of humic acids. The bottom of peat, phytoplankton and the highest aquatic vegetation is small, animals too. These lakes are distributed in very wetlands.

In the last decade, in the conditions of increased admission from the fields of phosphorus and nitrogen compounds, as well as the discharge of wastewater of some industrial enterprises, the lakes are energized. The first sign of this unfavorable phenomenon is the strong blooming of blue-green algae, then the amount of oxygen decreases in the pond, yers are formed, hydrogen sulfide appears. All this will create unfavorable conditions for the life of fish, waterfowl and others.

Evolution of lakes occurs different paths In a wet and dry climate: in the first case, they gradually turn into the swamps, in the second - in salt marshes.

In a wet (humid) climate, the leading role in filling out the lake and turning it into the swamp belongs to vegetation, partly the remnants of the animal population, which together form organic residues. Temporary watercourses and rivers bring mineral injuries. Small lakes with gentle shores will overgrow by adding plant ecological zones from the periphery to the center. Ultimately, the lake becomes a herbaceous lowland swamp.

Deep lakes with steep shores bump otherwise: by increasing from above Splavins (Zybun) - a layer of alive and dead plants. The basis of it is plants with long rhizomes (sabelnik, watch, whitefly), and other grassy plants and even shrubs (alder, Iva) are installed on the grid of the roots. The splavine first appears off the coast of the wind, where there is no excitement, and gradually coming to the lake, increasing in power. Part of the plants die, falls on the bottom, forming a peat. Gradually, only the "windows" of water remain in the global, and then they disappear, although the brand is not yet filled with sediments, and only with the time of the spline is closed with a peat layer.

In the dry climate of the lake, with time become salt marshes. This is facilitated by an insignificant amount of precipitation, intensive evaporation, reduction of river water influx, the deposition of solid precipitation, brought by rivers and dust storms. As a result, the water mass of the lake decreases, the level decreases, the area is reduced, the concentration of salts increases, and even fresh lake can turn first in salt Lake (Large Salted Lake in North America), and then in Solonchak.

The lakes, especially large, have a mitigating effect on the climate of the adjacent territories: in winter there is warmer, the summer is cooler. So, on the coastal meteorological stations at Lake Baikal, the temperature in winter at 8-10 ° S. above, and in summer at 6-8 ° S. lower than at stations outside the influence of the lake. Air humidity near lakes are more due to increased evaporation.

The origin of the lakes Kotlovin
Seafood in lakes

Lakes - Natural reservoirs with standing or low-dimensional water, resulting from the flooding of sushi reductions (kotlovin) with water masses. Lakes are not connected with the ocean and, unlike rivers, have a slow water exchange.

Each lake consists of three interrelated natural components:

1. basins - the form of relief of the earth's surface,
2. water masses with substances dissolved in it,
3. plants and animals inhabiting water.

The origin of the lakes Kotlovin

The lakes of the lakes arise as a result of various embedded processes and are divided into several groups by origin.

With the manifestation of endogenous activity, the formation of tectonic and volcanic kitelins is associated.

Basins of tectonic origin They are formed as a result of the movement of the land of the earth's crust. Many of the lakes arising in brands of tectonic origin occupy an extensive area, characterized by a great depth and have an ancient age. The great examples of lakes belonging to this group are the great African lakes (including Tanganic with a depth of -1470 m), dedicated to the East African rift system, where the processes of stretching and the bending of the continental crust occur. A similar origin has a Lake Baikal in Russia (which is the largest freshwater reservoir and has a maximum depth of -1620 m among lakes), Lake Biva in Japan (known to those produced in it with freshwater pearls) and others. The basins are often confined to isometric defamations (Chad, Eyr) or large tectonic faults. The formation is connected with tectonic processes. residual lakeswho are the remnants of the ancient oceans and seas. So, Caspian lake Separated from the Mediterranean and Black Seas as a result of the tectonic movements of the earth's crust.

Basins of volcanic origin Locked to crater and calderars of extinct volcanoes or are located among frozen lava fields. In the latter case, lake basins are formed when hot lava flows from under a colder surface lava horizon, which contributes to the sedimentation of the latter (it was formed. Yellowstone), or in the case of binding rivers and streams by lava or mud stream during volcanic eruptions. The basins of such origin are found in areas of modern or ancient volcanic activities (Kamchatka, Transcaucasia, Iceland, Italy, Japan, New Zealand and etc.).

The manifold of exogenous processes leads to the formation of various groups of lake kitlovin.

A large number of lake boilers have ice Origins. Their formation can be associated with the activities of mountain and lowland glaciers. In the mountains, glacier lakes are presented by seament and horses. Morning-hubs are formed when spent by the glaciers of river valleys. When filling with water of carriage, kitelins are formed small picturesque lakes With pure and cold water.
On the plains of the iceline of iceline is common in the territory subjected to quartered glaciation. Among them, it is possible to distinguish the hooks of exed, glacial and accumulative and minor-hovering origin. Examing basins are connected with the negative form of relief developed by the moving ice. The famous example of the lake, which is obliged to its origin of the destructive activities of glaciers, is Loch-Ness in Scotland formed in the river valley treated with the Glacier. Thousands of lakes formed in the ice plowing basins are found on the territory of the Scandinavian Peninsula, in the north of Canada. Glacial and accumulative basins are formed in the area of \u200b\u200bthe development of sea sediments. Lake basins in the field of marine-plain relief wide, have an oval shape and a small depth (moon, Ilmen); In the conditions of hilly-western and hilly-dummy reliefs have the wrong form, islands, complex coastline, dissected by peninsulas and bays (Seliger). Moroen-hovering basins arise when using by the Moraine Snadnikovy River Valley (for example, Oz. Saima in Finland).

In the regions of many years of marbles are formed basins of thermocarbon origin, obliged to melting melting ice and frozen rocks and soil preservations. Such an origin has many basins of tundra lakes. All of them have a small depth and small in the area. Another area of \u200b\u200bthe development of thermocarbon kitelin is the area of \u200b\u200bdistribution of ferechny fluviohydial deposits. Here, when melting the covering glaciers under the thickness of the sediments made by the melted glacial waters, huge boulders were buried dead Ice.. Many of them melted only hundreds of years, and the basins filled with water appeared in their place.

Lakes basins of karst origin They are formed in areas composed by soluble (cruising) rocks. The dissolution of rocks leads to the formation of deep, but usually minor by Kotlovin area. Here, there are often failures caused by the collapse of the archives of underground karst cavities. Examples of Karst Kotlovin can serve as the famous "failure" in Pyatigorsk (known for the novel of Ilf and Petrov "Twelve Chairs") and Oz. Pharmacy French Alpshaving a depth of -99 m at an area of \u200b\u200bonly 57 hectares.

Lakes basins of suffosic origin Formed when cutting soils due to the removal of underground waters of loose dust particles. The basins of this genesis are found in the steppe and semi-desert zones of Central Asia, Kazakhstan and the West Siberian Plain.

Basins of fluvial origin related to the geological activity of rivers. Most often these are old and delta lakes. Sometimes the formation of lakes is due to the blocking of the riverbed by the Alluvial nanos of another river. For example, the formation of the Saint Curra Lake (USA) is associated with the binding r. Saint-Curia Alluvial sediments p. Mississippi. Due to the dynamicness of erosion and accumulative fluvible processes and small size, Kotlovin, the latter are relatively quickly filled with nanos and overflow in some places and are re-formed in others.

Some lake basins are formed as a result of binding with landslides, mountain colors or villages of rivers. Typically, such lakes exist for a short time - a breakthrough of the nanos forming the "dam" occurs. So, in 1841 p. Indo on the territory of modern Pakistan was led by a landslide resulting from an earthquake, and after six months "Dam" collapsed, and a lake of 64 km long and a depth of 300 m was lowered in 24 hours. Lakes of this group can remain stable under the condition that the excess water is discharged through solid rock-resistant. For example, the Sarezo lake formed in 1911 in the valley of the river. Murgab on the Eastern Pamir, there is still still a depth of -500 m (the tenth place in depth among the lakes of the world).
The process of binding the river with a powerful collapse contributed to the formation of one of the "pearls" of the Caucasus - Ricz Lakes in Abkhazia. The gigantic collapse on the slope of Mount Psogesti damaged the Lashipse River. The water of the river more than 2 km flooded the gorge (tracing a large tectonic spill in the thickness of rocks), the water rose by 130 m. From under the natural stone dam, a river is knocked out with an already other name - Yupshara (by Abkhaz "split").

Lakes artificial origin Associated with the filling of the water of artificial kitelin (quarries, etc.), or with the binding of river fluxes by dams. When building, dams are formed different in the size of the reservoir - from small ponds to huge reservoirs (Victoria Reservoir on Africa on the Victoria River, Volta on the river. Volta and Cariba on the r. Zambezi; The largest in Russia is a fraternal reservoir on the river Hangar). Some dams were raised to produce electricity for aluminum smelting based on large bauxite deposits. It is necessary to add that dams are created not only by a person. Dams built by beabonds can reach lengths more than 500 m, but there are only short time.

Basins of coastal marine origin They are formed primarily as a result of the separation of sea bays from the sea water area during the movement of the movement of the disintegration. At the initial stage, the basin is filled with salty seasy watersIn the future, the resulting salty lake is gradually exposed.

Basins of organogenic origin arise on sphagnous swamps of taiga, timber tundra and tundra, as well as on coral Islands. In the first case, they are obliged to be an uneven increase in Mukov, in the second - coral polyps.

Lakes across geological time exist relatively long. The exception is only some lakes with basins of tectonic origin, dedicated to the active zones of the earth's crust, and large residual lakes. Over time, the basins are filled with precipitation or fever.

Seafood in lakes

The deposits of lakes are represented by terrific, chemogenic and organogenic precipitation. The composition of precipitation accumulating in lakes is determined primarily by climatic zonality.

In the lakes of the humid regions, predominantly aneur-clay deposits accumulate, often with a large number of organic. Dead organisms, as well as the material demolished in the lake, are postponed on the day and form gitto. (from the Swede Gyttja - Il, Tina) - lake deposits consisting of organic residues. The organic matter of the gits is formed mainly due to the products of the decay of vegetable and animal organisms living in the water, to a lesser extent by the residues of land plants brought from the surrounding sushi. The mineral part consists of sand-clay material and precipitated from water calcium, iron and magnesium oxides. The guitty is also called sapropel (from Greek. Sapros - rotten and Pelos - Il, dirt - "putrebral il"). In Lake Nero, located at the city of Rostov-Yaroslavsky (Great Rostov), \u200b\u200bthe Sapropel layer reaches 20 m. Sappropels are used as fertilizer or as mineral feeding for livestock; Sometimes in balneological purposes (mud).

In semi-desert and desert arid zones of lakes with intensive evaporation. Since rivers and groundwater always bring salts, but only clean water evaporates, then there is a gradual increase in the saline of lake waters. The concentration of salts can increase so significantly that from the water suspended (RAPA), salt is precipitated to the bottom of the lake (self-peasant lakes). With the coalion of continental lakes, carbonate, soda, sulfate, hydrochny and other hemogenic deposits are accumulated. In Russia, modern soda lakes are known in Transbaikalia and in Western Siberia; Large Natron in Tanzania and Lake Serls in California uses abroad. Fields of natural soda are timed to fossil sediments of such lakes.
In general, halogen-carbonate sediments are characterized for arid areas, poor organic.

In some cases, a decisive role in the nature of sedimentation has the origin of laketry kotlovin. For glacial lakes, tape clays are characterized, which are formed due to the combination of lake and glacial sediments. Carbonates are accumulated in karst lakes, sometimes jams of chipping of oblivioning origin.

Acquaintance with varieties, geographical location, temperature regime of waters and chemical composition of Lakes of Russia.

Studying the location, square and indicators of the depth of the largest domestic reservoirs - Baikal, Ladoga and Onega Lakes.

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Technogenic influence on the ecosystem of the lake.

abstract, added 01/26/2010

Getting quantitative estimates of the regulatory ability of Onega Lake

Hydrography of the waterboat of the lake basin.

Quantile analysis of many years of variability of hydrometeorological characteristics. Features of the long-length instability of temperatures and precipitation. Methods of the theory of periodically cornerled random processes.

thesis, added 04/27/2018

Significant water reserves are concentrated in the lakes. Russia has more than 2.5 million lakes. The largest lakes are Caspian, Ladoga, Onega and Baikal.

The Caspian Lake is the biggest lake in the world, the deepest - Lake Baikal. Lakes are very unevenly distributed.

In particular, in Vilenovsky, the Western Siberian Plain and the North-West Layer of Europe in Karelia. All these areas are in too much humidity. In the south, in the zone of the steppe and semi-atrocondary zone with a weak climate, the number of lakes decreases sharply, and many lakes have salt or salt. Salt is such huge large lakes, like Caspian, as well as Lake Elton and Baskunchak, where the salt is eliminated.

Hydrographic characteristics of large lakes in Russia

There are different lakes and sources of pools.

Lakes of tectonic origin are located in the gutters and cracks of the earth's crust. The largest tectonic lake Baikal is located in Graben, reaching a depth of 1637 m.

Ice-tectonic lake pools were created as a result of treatment of liquid depressions of the glacier ice cortex: Imandra, Ladoga, Onega.

In Kamchatka and on Kuril Islands The lake is mainly related to volcanic origin. In the north-west of the European Plain, the origins of lake pools are associated with continental ice. Many caves are located between the hills of the sea: Seliger, Valdai.

Due to landslides in mountain valleys Lake lake: Sirez in Pamirs, Rice in the Caucasus. Small lakes are formed by karst nests.

In the south of Western Siberia, there are many lakes in the form of plates, which were created as a result of clogging by stones of stones. When the ice melts on the surface of permafrost, minor water is also formed, similar to the stove. Ozerny people are located on the floodplain plains of lowlands. On the coast of black and Azov Sea There are lakes estuaria.

All the largest and largest lakes of Russia are often used in the national economy. Catch and catch in them. Especially a lot of fish, including the most valuable sturgeon, fall into the Caspian.

In Baikal Harvest - Omul. Lakes are also used to navigate - geoglobus.ru. Numerous minerals were acquired in the lakes of the lakes: oil and mirritis in the Caspian Lake, salt in Elton and Baskunchak. Water for freshwater lakes is used for drinking. On the shores of many lakes there are many sanatoriums, holiday homes.

There are nine lake areas in Russia:

1) north-West Lake, Iceberg Icebergs;
2a) Azov-Black Sea estairi associated with maritime activities;
2b) North Caucasian - glacier and karst lake;
3) salt formation of the Caspian lake;
4) West Siberian-Tuscan and bitter-salt lakes;
5) Altai - Sea Type of lakes (Teletskoye, Markakol);
6) Zabaykalsky - the remaining lakes;
7) Nizhneyamur lakes having a hydrological connection with the Amur River;
8) Yakuti - Lakes from the thermocouple;
9) Lake Kamchatka - Lake of Volcanic Origin (Kronotsky, Kurilsky).

Definition 1.

In the aspect of planetology, the lake is a stably existing object in space and time, which is filled with a substance in the liquid form.

In the geographical sense, it can be represented as a closed deepening sushi into which water is systematically. For a sufficiently long period of time, the chemical composition of the lakes does not change. Filling its fluid is updated, but much less often than in the river. At the same time, those present in it do not act as the main factor by which it is possible to determine the general mode.

Note 1.

Lakes mainly provide balancing of river flow, as chemical complex reactions occur in their waters.

In the process of interactions, some elements go into liquid, others settled in bottom sediments. In some reservoirs that do not have such a flow, salts content due to evaporation increase. As a result, a cardinal change in the mineral and salt composition of lakes occurs. Large objects soften the climatic conditions of the territories close to them through large-scale thermal inertia, thereby reducing seasonal and annual weather oscillations.

Tectonic lakes: characteristics, examples

Definition 2.

Tectonic lakes - reservoirs, which were formed in areas of faults and shifts of the earth's crust.

Basically, these objects are narrow and deep, and also differ from straight sheer shores. Such lakes are located mainly in deep-cutting gorges. Tectonic lakes of Russia (examples: Far and Kurilsky on the territory of Kamchatka) are characterized by a lowest bottom. So, the Curilian reservoir flows in the southern part of the Kamchatka, in a colorful deep hollow. This area is completely surrounded by mountains. The maximum depth of the lake is about 360 m, and a huge amount of mountain streams constantly flows from the rumble shores. The lake river flows from this reservoir, along the shores of which enough hot springs come to the surface. In the center of the reservoir there is an island in the form of a small mud-shaped elevation, called the "Heart-Stone" people. Not far from the lake there are unique submarines of Pemps, which are called Cuthhina Bata. Today, Lake Kurilsky is considered a reserve and declared a natural zoological monument.

Interestingly, tectonic lakes are located only in the tubes of the explosion and extinct crater. Such reservoirs are often found in European countries. For example, volcanic lakes are observed in the Eifel area (in Germany), near which a weak manifestation is fixed. volcanic activity In the form of hot springs. Water-filled Crater is the most common type of similar reservoirs.

Example 1.

For example, the lakes of Kray-ter Vulcan Mazam on the territory of Oregon formed approximately 6.5 thousand years ago.

Its diameter reaches 10 km, and the depth is more than 589 m. Part of the reservoir was formed by volcanic valleys in the process of blocking continuous lava flows, in which water accumulates over time and the lake is accumulated over time. It is thus that a pond of Kivu is a depression of an East African rift structure, which is located on the border of Zaire and Rwanda. It flows over 7 thousand years ago from Tanganic River Ruzisi proceeded through the Kiviv Valley to the northern regions, towards the Nile. But from that period, the channel was "sealed" in the eruption of a nearby volcano.

DNA profile of tectonic lakes

Tectonic water bodies have a clearly outlined bottom reliefrepresented in the form of a broken curve.

Accumulative processes and glacial sediments in precipitation did not have a significant impact on the relief of the lines of Kotlovin, but in a number of special cases the influence may be quite noticeable.

Glacial and tectonic lakes can be covered with "scars" and "broods" bottom, which can be observed on rocky shores and islands. The latter are formed mainly from hardening rocks that are practically not amenable to erosion. As a result of this process, a small precipitation rate arises. Similar tectonic reservoirs of Russia geographers refer to categories: a \u003d 2-4 and a \u003d 4-10. The deep-water surface (over 10 m) from the total volume reaches approximately 60-70%, shallow (up to 5 m) - 15-20%. Such lakes are characterized by diverse waters in thermal indicators. The low temperature of the bottom water is maintained during the maximum surface heating. This is caused by thermal stable stratification. The vegetation in these zones is extremely rare, as it is possible to detect it only on the shores in the closed bays.

Features of the formation of water bodies

Lakes arise for a variety of reasons. The natural creators are:

• water;
• wind;
• tectonic forces.

On the earth's surface, the basins are often washed out by water. Due to the action of the wind, a deepening is created, after which the glacier carries out the grinding, and the mountain collar gradually populates the river valley. This is formed the bed for the future reservoir.

By the origin of the lake is divided into:

• river reservoirs;
• seaside lakes;
• mountain reservoirs;
• ice lakes;
• bonding reservoirs;
• tectonic lakes;
• feling lakes.

Tectonic lakes appear as a result of filling with water of small cracks in the crust. So, the shifts were formed by the Caspian Sea - the largest reservoir in Russia and the entire planet. Before raising Caucasian ridge The Caspian Sea directly contacted black. Another bright example of a large-scale fault of the earth's crust is the East African structure, which extends from the south-western district of the continent to the north to the south-east of Asia. Here is a chain of tectonic reservoirs. The most famous are Tanganica, Albert Edward, Nyasa. To the same system, experts include the Dead Sea - the maximum lowered tectonic lake of the world.

Seaside lakes are limans and lagoons, which are mainly located in the northern regions Adriatic Sea. As one of the specifics of failed reservoirs, their systematic disappearance and occurrence. it a natural phenomenon Immediately depends on the unique dynamics of groundwater. The ideal example of the specified object is the lake of Erztsov, located in South Ossetia. Mountain reservoirs are located in the range of hollows, and glacial lakes are formed when the thickness of many years of ice is shifted.

They are formed in places of faults and shifts of the earth's crust. As a rule, these are deep narrow reservoirs with straight-bearing shores, located in deep-cutting bottom gorges of those located on Kamchatka, the lakes are lower than the ocean level. Tectonic lakes include far and Kuril. The Kuril Lake is located in the south of Kamchatka in a deep picturesque basin, surrounded by the mountains. The greatest depth of the lake 306 m. The shores of his climbers. Numerous mountain streams flow from them. Lake Soykochka, it takes the beginning of the River Ozernaya. On the shores of the lake on the surface are hot springs, and in its middle it is elevated the island, which is called the heart-stone. The lake from the lake is located a unique outcrop of PEMZ, which are called Cuthhina Bata. Currently, the lake is announced by the Reserve and Zoological Monument of Nature.

The bottom profile of the tectonic lakes is sharply outlined, has a form of a broken curve. Glacial sediments and precipitation processes have little changed the clarity of the tectonic lines of the lake. The influence of the glacier on the formation of the basin is noticeable, he leaves the traces of his stay in the form of scars, lambs, which are well visible on rocky shores and islands. The shores of the lakes are complicated mainly from hardening rocks, weakly denominated erosion, which is one of the reasons for the weak process of sedimentation. These lakes belong to the group of lakes of normal depth (A \u003d 2-4) and deep (A \u003d 4-10). The deep-sea zone (more than 10 m) from the total volume of the lake is 60-70%, shallow water (0-5m) 15-20%. The water lakes are thermally heterogeneous: during the greatest leveling of surface water, low bottom temperatures are preserved, which is promoted by stable thermal stratification. Water vegetation is rare, only a narrow strip along the shores of closed bays. Typical lakes in the pool r. Suna are large and medium: paligues, Sundozero, sandalwood, as well as very small Lakes Salvilamby and Randozero, located on private waters of lakes pallets and sandalwood.

As a result of the movement of the earth's crust in some places, recesses are formed. In these recesses and tectonic lakes arise. Three most large lakes Kyrgyzstan: Issyk-Kul, Son-Kul and Chatyr-Kul are formed by tectonic way.

Many lakes and in the forest-steppe service. Here are such large reservoirs like Welga, Shablash, Argayash, B.Kuash, Kalda, Sugoyak, Tishka, etc. The depths of the lakes on the Zauralsky Plain are noticeably reduced and do not exceed 8-10 m. By origin, these lakes are related to erosion-tectonic type. Tectonic depressions were modified as a result of the impact of erosion processes. Many lakes of Zauralya are confined to the ancient places of the flow of rivers (Etkul, sandy, Alakul, Reed, etc.).

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