Lake Onega in Karelian. Lake Onega
"Onego-father" - this is how the Russian people who lived on the shores of Lake Onega from antiquity called their breadwinner, what they considered this quiet, transparent expanse framed by picturesque shores under the sky, shining with pearl light through the veil of almost permanent clouds here.Russian scientist, historian and archaeologist of the late 19th century, founder of the Russian school of ethnography H.N. Kharuzin (1865-1900) in his work “Materials collected among the peasants of the Pudozh district of the Olonets province” cites such an appeal to the lake, recorded by him: with the incoming guests, bless the water to take not for the sake of cunning, not for the sake of wisdom, but for the sake of goodness and health ... ”In addition to the sacral and ritual intonation, one can also read the sincere gratitude of people to the lake - for the purity of its water, for the abundance of fish in it and timber on it shores. And, of course, for the beauty that pleases the eye and soul. And now the townspeople coming to Lake Onega to see wooden architecture reserve "Kizhi", "demons" - petroglyphs of Cape Besov Nos, go fishing, just relax and unwind, all as one say that they experience an unusually strong surge of spiritual strength here.
The name Onego is Sami by origin, like many original names settlements on its shores, which is a clear answer to the question of who mastered these shores. The Scandinavians and Russians also call the Finno-Ugric Saami the Lop, Loplyans and Lapps (this is where the toponym Lapland comes from). The Vepsians (Chud) also lived here. The Slavs came here in the 5th century. In the Sami language, the word ale, or elo, which was transformed in Russian into Onego or Onega, simply means " big lake". It is a large, second largest water surface in Europe after Lake Ladoga, with which it is connected by the only river flowing from Onego - the Svir, while about 50 rivers flow into it. As for the more ancient inhabitants of the shores of Lake Onega, archaeological excavations on the islands of the southern Zaonezhye Big Lelikovsky and Small Lelikovsky testify that people lived there settled from the Neolithic era (the turn of V-IV - the beginning of the III millennium BC).
Geologists attribute the rocks that form the basin of the lake to the Proterozoic period. Hydrologists believe that this basin was filled mainly with water from melting glaciers, as well as underground sources. At the same time, the channels of the rivers flowing into the lake were formed. The location of the fjords in the north and northwest of the lake, rocky ridges and placers of small islands covered with granite boulders between them in the bays (bays) on the map of the lake are a kind of schematic reproduction of the movement of the ice cover on the ground here. This movement happened gradually and in different periods. ancient glaciation European continent, powerful jerks and shocks, generated, as is quite obvious, by tectonic processes during the movement of the margins of lithospheric plates. Under the influence of these processes, the larger islands of the lake were also formed, the total number of which, together with the very tiny ones, is about 150. The largest of the islands is Bolshoi Klimetsky (Klimenetsky), whose area is 147 km 2; There are several settlements here, a school operates. Other large islands are (Kizh), Kerk, Deer, Sennogubsky, Suysari. Large islands fall on the northern segment of the lake.
Depths in the southern segment of the lake in coastal water spaces range from 9 to 14.5 m. Netak in the north. Bottom depressions begin from the line Petrozavodsk - the mouth of the Vodla River, some reach depths of 111, 115.5 and even 132.5 m, although 127 m are still considered the maximum depth. water in Onega can vary depending on the strong winds prevailing in a given year, moving layers of water, or the amount of precipitation.
Lake Onega on the territory of Karelia (mainly), Leningrad and Vologda regions extends from north-northwest to south-southeast. The maximum length of the lake - between the Black Sands coast in the south and the mouth of the Kumsa River in the north - reaches 220 km, and the width - from Lake Logmo, in fact, the continuation of Onega, to the village of Pudozhsky churchyard - 86 km. The coastline in the south has a relatively smooth character, in the north it is indented by narrow fjords bordered by skerries.
Some were created by nature, others by man. It makes no sense to talk about which ones are more important, they are all valuable - because, in fact, they are inseparable.
The natural resources of Lake Onega are not fundamentally different from those of Lake Ladoga or, say, Lake Vänern in Sweden, because all these lakes Northern Europe stand on the same geological Baltic granite shield, have a common history of origin, similar climate and hydrology. True, Onega belongs to the Baltic Shield only in its northern part, and in its southern part - to the Russian platform. The non-specialist will not notice this, but any person who understands the dim northern nature, rejoice that he sees the desert again sandbars, rocky capes, avant-garde detachments of virgin coniferous forests. And also to the fact that he can stay in silence and go fishing from the heart here in clean water. The bottom of the lake with its silty areas, elevation changes from deep holes to shallow water, underwater ridges contribute to the fact that different breeds of fish are found here, and they fatten up a lot of body weight. The ichthyofauna of Lake Onega includes 47 species and varieties of fish. Among them are sterlet, salmon, trout, lake and stream, pike, whitefish, grayling, eel, etc. The lake begins to freeze around mid-December, but this circumstance is not the main obstacle for lovers fishing and short daylight hours.
Onega is connected with Ladoga by the Svir River, with the White Sea by the White Sea-Baltic Canal. And so on: with the Volga, the Caspian and Black Seas - through the network of canals of the Volga-Baltic waterway.
In total, 552 are registered on the coast of the lake today man-made monument. Among the petroglyphs of Onega, the most famous, whose age is 5-6 thousand years, are those located on Cape Besov Nos, especially three large "figures" - an anthropomorphic "Bes" 2.3 m long, along the entire "body" of which there is a crack , looking really ominous, “Otter” (or “Lizard”) and “Burbot” (or “Catfish”). There are other places on Onega with Neolithic monuments, no less interesting, on the rocky outcrops of the coast from the mouth of the Vodla River to the mouth of the Chernaya River: it is better to learn about them and the road to them on the spot, tourism infrastructure here, alas, is not yet very developed. The technique for creating these images is common for the Neolithic: dot-cutting on stone. On the peninsula Kochkovnavolok at the mouth of the Vodpa there are open in the 1980-1990s. northernmost cave drawings Lake Onega. Anthropomorphic figures are also found here, while images of animals predominate, and among them - swans (there are swans in other accumulations of petroglyphs). The largest local “swan” from head to tail is 4.12 m. These petroglyphs are much worse preserved than on the Besovy Nos: erosion has affected, some images are overgrown with lichens, and yet the most valuable impression from what they saw here is that the ancient hunters and fishermen thought not only about food, they also admired the surrounding world and, judging by the size of some figures, deified it, because the swan is not at all a game bird, but the personification of beauty and purity.
The beauty of the wooden buildings collected on the island of Kizhi in State Museum-Reserve Russian Orthodox wooden architecture"Kizhi", or "Kizhi Pogost", is listed world heritage UNESCO. In addition to the churches originally built on the island itself, chapels, houses and outbuildings from Zaonezhye and other regions of Karelia were moved here with all possible care. About the “piecework” of the exhibits of this museum under open sky tell many stories. The most famous of them is the carpenter Nestor, who built the Church of the Transfiguration of the Lord with one ax (initially without a single nail), threw the ax into the lake so that no one could copy his work.
general information
Lake glacier- tectonic origin on the territory of the Republic, Leningrad and Vologda regions in the north-west of the European part Russian Federation.Education time: about 12 thousand years ago, with the end of the last Valdai glaciation.
According to hydrographic parameters, Lake Onega is included in the water basin of Lake Ladoga and the Neva River.
Type: fresh.
The most significant flowing rivers: Vytegra, Suna, Andoma, Vodla, Shuya.
The largest islands: Bolshoy Klimetsky, Bolshoy Lelikovsky (in the southern Zaonezhye), Kerk, Deer, Sennogubsky, Suysari.
Cities: Petrozavodsk, Kondopoga, Medvezhyegorsk, urban-type settlement Povenets.
Outflowing river: Svir.
Nearest airports: Pulkovo in St. Petersburg (international), Besovets in Petrozavodsk.
Numbers
Length: 220 km.Maximum Width: 86 km.
Note: different sources give different indicators of the length and width of the lake.
Water surface area: 9720 km 2 (excluding islands, whose area is 224 km 2).
Total number of islands: more than 1500.
Water mass volume: 295 km3.
Length coastline : 1280 km.
Max Depth : 127 m.
catchment area: 62,800 km2.
Water transparency: 1.5 to 8 m.
Climate and weather
Transitional: from temperate continental to maritime.January average temperature: -9°C.
July average temperature: +16°С.
Maximum water temperature in July-August: +24°С.
Average annual rainfall: 610 mm.
Economy
Shipping.Fishing.
Tourism.
Attractions
■ Petrozavodsk: Cathedral Alexander Nevsky (1826), Exaltation of the Cross Church (1852), Onega Embankment - an open-air museum, which houses a monument to the founder of the city, Peter I, monuments-gifts from sister cities, the Wishing Tree, other sculptures and structures, the Park culture and recreation - the former Petrovsky Garden, founded in 1703, oldest park Russia.■ Kondopoga: wooden church Dormition Mother of God(1774), local history museum, Ice Palace(2001).
■ Petroglyphs of Cape Besov Nos, the Kochkovnavolok peninsula and other rocky ledges on the banks.
■ Kizhi Island- State Historical, Architectural and Ethnographic Museum-Reserve "Kizhi" (UNESCO World Heritage Site): ensemble "Kizhi Pogost": the Church of the Transfiguration of the Lord (1714), crowned with a complex system of 22 domes arranged in 4 tiers; the Church of the Intercession of the Virgin (1764), the Tent Bell Tower (1863), the oldest wooden church in Russia - the Resurrection of Lazarus from the Murom Monastery (XIV century), as well as other churches, chapels, peasant houses, barns, a mill, rigs - a total of 76 buildings.
■ Monuments of Pegrema(opened in 1985) - an archaeological complex 1.5 km from the village of Pegrema on the Zaonezhsky Peninsula 100 monuments from different eras, including a unique cult complex (III-II millennium BC): boulders resembling figures people and animals.
■ Bolshoi Klimetsky Island.
Curious facts
■ Slava near Bolshoi Klimetsky Island anomalous place. Lovers of interpreting mysticism explain the origin of such stories by the fact that there is an “entrance to parallel worlds”. Ancient legends about ghosts and “witch lights” wandering around the island can be immediately attributed to the phantasmagoria of an inflamed consciousness, because it is known that there was an ancient temple on the island. But there are still unexplained facts of our time. So, in 1973, the captain of the fishing vessel Pulkin disappeared here. It is impossible to imagine that he got lost, he is a local, experienced person. Pulkin appeared 34 days later, dirty, ragged and emaciated. But he didn’t really tell anything, he only repeated that he didn’t remember where he was and what happened to him. In 2008, a local fisherman, Yefimov, said that “someone” drove him in the same circle five times in a row. In the summer of 2009, a group of students moored ashore. But as soon as they pitched their tents, they heard a rumble coming from somewhere out of the ground. All began severe headaches and nausea. The frightened youth quickly packed up and set off on their return journey. As soon as the guys sailed from the shore, all unpleasant symptoms receded.■ From time to time there are rumors about increased levels of radiation on Kizhi Island. Scientists of the Karelsky Institute of Geology scientific center The Russian Academy of Sciences, on the basis of their research, refuted these idle conjectures.
■ The word "trolling" in the language modern man is associated primarily with some kind of hoax, deliberate challenge, provocation, manipulation. Most often it appears in in social networks- both as a mode of action and as a term. However, the primary origin of this word is from the lexicon of fishermen. This is a fishing method. On Lake Onega, trolling at medium depths, from 30 to 60 m, is widely used. Its essence is to hold the bait in the water from a boat or from a motor boat. When trolling, up to 10 rods are used. They are installed on the sides with the help of special devices.
■ Since 1972, Russia's largest international multi-day sailing regatta has been held on Lake Onega at the end of July. Mostly cruising yachts of the Orel 800 class participate in the races, since 2003 yachts of the Micro class are also allowed to compete. The regatta starts and finishes in Petrozavodsk. Lake Onega is a lake in the north-west of the European part of the Russian Federation, located on the territory of Karelia, the Leningrad and Vologda regions. The second largest lake in Europe after Ladoga. Belongs to the Baltic Sea basin Atlantic Ocean. The area of \u200b\u200bthe lake without islands is 9690 km 2, and with islands - 9720 km 2; the volume of water mass - 285 km 3; length from south to north - 245 km, maximum width - 91.6 km. The average depth is 30 m, and the maximum depth is 127 m. The cities of Petrozavodsk, Kondopoga and Medvezhyegorsk are located on the shores of Lake Onega. About 50 rivers flow into Lake Onega, and only one flows out - the Svir.
The average depth of the lake is 31 m, the maximum depth in the deepest northern part of the lake reaches 127 m. The average depth in the central part is 50-60 m, closer to the south the bottom rises to 20-30 m. bottom depressions. In the northern part of the lake there are many troughs, alternating with high bottom rises, forming banks, on which industrial trawlers often fish. Much of the bottom is covered with silt. Typical forms are luds (shallow stony shoals), selgas (deep-water elevations of the bottom with stony and sandy soils, in the southern part of the lake), underwater ridges and ridges, as well as depressions and pits. Such a relief creates favorable conditions for the life of fish. The regime of Lake Onega is characterized by a spring rise in water, which lasts 1.5-2 months, with an annual water level amplitude of up to 0.9-1 m. The flow from the lake is regulated by the Verkhnesvirskaya hydroelectric power station. Rivers bring up to 74% of the incoming part of the water balance (15.6 km 3 per year), 25% falls on precipitation. 84% of the expenditure part of the water balance falls on the runoff from the lake along the Svir River (an average of 17.6 km 3 per year), 16% - on evaporation from the water surface. The highest water levels of the lake are in June - August, the lowest - in March - April. There are frequent unrest, storm waves reach up to 2.5 m in height. The lake freezes in the central part in mid-January, in the coastal part and in the bays - in late November - December. At the end of April, the mouths of the tributaries are opened, the open part of the lake - in May. The water in the open deep parts of the lake is transparent, with visibility up to 7-8 m. In the bays it is slightly less, up to one meter or less. The water is fresh, with a mineralization of 10 mg/l.
Lake Onega is the second largest lake in Europe. This lake is 2 times smaller than Lake Ladoga and contains three times less water. However, at the same time, the water in Lake Onega is of the highest quality: it is much cleaner than Ladoga water, and even water in Baikal.
The length of Lake Onega from north to south is 248 kilometers, and from west to east - 96 kilometers. There are a large number of capes, islands, bays and bays. The total number of all islands is 1500.
The shores of the lake are mostly sandy and pebbly, but at the same time, rock outcrops can also be found. coast northern region Lake Onega are composed of crystalline rocks, they are rugged and elevated. The relief of the bottom of the lake is quite simple, especially in its northern part. Almost all types of fish that are known in the reservoirs of Karelia are found in Lake Onega. More than 110 tributaries flow into this lake.
Onega lake. general characteristics
Lake Onega is one of the largest freshwater reservoirs in Karelia, which is located in its southeastern part. The total area of the water surface of Lake Onega is 10,050 km2, and the total area, together with the islands, is 10,340 km2. The maximum width of the lake is 248 kilometers, and maximum width- 83 kilometers. The total number of islands is 1650, with an area of 290 km2. The length of the entire coastline is 1542 kilometers, and together with the islands - 2699 kilometers. The total volume of water masses is 295 km3. The height of Lake Onega above sea level is 33 m2.
The lake has an elongated oblong shape from the northwestern to the southeastern part. Lake Onega is divided into several large bays and reaches. It is divided into 3 main parts:
- The main part is the Central Onego.
- North-western region - Big Onego.
- The northeastern region, which consists of Small Onego, Kuzaransky Onego, Pyalemsky Onego, Tolvuysky Onego, Povenets Onego, Big Bay and a number of small bays.
Basically, sandy and rocky shores prevail here. Rocky shores are common in the northern part of the lake and in the area west coast. sandy shores stretch from the mouth of the Vodla River to the source of the Svir River.
The area of the river basin of Lake Onega is 51,540 km2. From it, about 16 km3 of water enters the lake every year.
The water level in the lake changes every year. This is mainly due to the amount of precipitation. A constant current is expressed only in some parts of Lake Onega and is weak.
Lake Onega is one of the deepest reservoirs in Karelia (after Lake Ladoga). His average depth is 29.4 meters, and the maximum depth is 120 meters. Approximately 26 percent of the total area of the lake is located at a depth of up to 10 meters, 42 percent at a depth of up to 20 meters, 69 percent at a depth of up to 40 meters, and 92 percent at a depth of up to 60 meters.
The relief of the bottom of Lake Onega is quite complex. This is especially true for the northern part of the lake. This lake is characterized by depressions and elevations of the bottom. Typical landforms for the lake are selgas, luds, underwater ridges and thefts, pits and depressions. In addition, there are also some areas with a flat bottom in the lake. The soils of Lake Onega are very diverse. There are rocky, rocky-sandy, sandy and sandy-gravel soils. The colors of the water in Lake Onega range from light yellow to yellow or orange-brown.
Onega lake. Flora and fauna
Higher aquatic vegetation is the least common in Lake Onega. Its thickets can be found only in the northern part, in small bays and other places that are protected from waves.
The total length of thickets is approximately 1 percent of the length of the entire coastline. Basically, these thickets consist of reeds, and in some places you can find pondweeds, reeds, water lilies, horsetails, villains, egg capsules, sedge and other types of vegetation.
The fauna of the lake is quite diverse, if we talk about its quality. Here you can see aquatic insects, mollusks, crustaceans, water mites, worms, bryozoans, sponges and others. There are only 350 different forms and species of benthic fauna in Lake Onega, however, only 30 percent of them have a significant distribution in the lake itself, while the rest are quite rare.
The richest and most diverse is the population of the thickets of the littoral, which make up about half of the forms and species known for this lake.
The average biomass volume of the bottom mass of the lake in summer and autumn is 11.5 kg/ha, with an average abundance of 5.72 million ind./ha.
Of all the benthic fauna of Lake Onega, crustaceans, including pontoporea, are the most valuable food for fish. Oligochaetes, in turn, are rarely used by fish as food. The most significant accumulation of food objects is found in pits and depressions with a depth of up to 50 meters.
If we talk about the crustacean plankton of the lake, then it is distinguished by a significant species diversity of composition. In general, 37 species of lower crayfish live in the lake.
In the coastal shallow waters of Lake Onega, one can find various forms of planktonic crayfish. Planktonic crustaceans reach the highest quantitative development in summer in surface layer water.
By the abundance of crayfish, as well as by their biomass in the horizon up to 2 meters, Lake Onega is a medium-productive reservoir in the entire republic. However, individual sections of this lake are not equivalent in terms of food resources in shallow, most heated areas.
In addition, if we talk about the feed ratio, then here the composition of the crustacean plankton of Lake Onega has a number of positive features. The plankton of the lake is dominated by cladocerans, most of which are valuable food substances, which include holopedium and bosmins.
Onega lake. Fish
In Lake Onega, you can find almost all types of fish that are known for the reservoirs of Karelia. This lake is inhabited by sturgeon (sterlet), salmon (salmon, trout, brook trout, ludny trout, pit trout, vendace, whitefish), chorius (grayling), smelt (smelt), pike (pike), cyprinids (roach, dace, silver bream, sabrefish, bream, golden crucian carp), loach (whiskered char, loaches), catfish (catfish), eels (eels), perch (perch, perch, ruffs), gobies (Onega slingshots, lops, sculpins), stickleback (nine-spined sticklebacks, three-spined sticklebacks), cod (lake burbot and lake-river burbot). Of the minigas, the river lamprey and stream lamprey are the most common.
In general, 47 varieties and species of fish live in Lake Onega, which belong to 13 families and 34 species. It is possible to find a chub in the lake.
17 species of fish are endowed with the greatest fishing value in the lake, namely vendace, whitefish, ruffs, roach, pike, char, pike perch, smelt, salmon, bream and perch, and the smallest - crucian carp, ide, dace, bleak and grayling. Other fish species in Lake Onega are quite rare.
The main commercial fish of this lake is the vendace. It is widespread in almost all places. The vendace feeds only on crustacean plankton. In turn, kilets is a large form of vendace. It is mainly found in the southern part of the lake. Smelt is an object of mass fishing. But at the same time, it will also happen as food for fish such as pike perch, salmon, burbot and char. If we talk about whitefish, then in Lake Onega they are noted in 9 different forms. In addition, all whitefish are divided into 2 large groups- these are lake-river whitefish and lake whitefish. Also in Lake Onega there is also burbot, or rather its two forms - lake-river and lake burbot. Burbot as well as vendace is ubiquitous. Pike perch is one of the most valuable fishery objects on the lake, but its catch is rather small. However, the most common and numerous fish in Lake Onega is the ruff, which is found at a depth of up to 70 meters. Perch can be found mainly in coastal areas, as well as in shallow water. open lake. Breams are found here in the area of estuaries and sources of rivers. But the pike is not of significant importance in the fishing of the lake. It lives in shallow, vegetated areas. If we talk about salmon, then in Lake Onega there are several herds of this fish. Now the most numerous is the herd of Shuya salmon.
But one of the most valuable fish of the salmon family is char, which is common in the area adjacent to the deepest parts of the lake. ide in this lake has insignificant commercial value, but grayling can be found almost everywhere. Very rarely in Lake Onega there are golden carp, unlike bleak and dace.
In the wonderful northern region of Karelia, among the rocks, forests and swamps, there is a large Lake Onega, which is often called the younger brother of Ladoga. Maybe because it is the second largest lake in Europe, or maybe also because they were formed almost simultaneously, after the retreat of the last glaciers. And although Lake Onega is almost two times smaller and much shallower than Lake Ladoga (average depth is 30 meters), the water here is of very high quality, it is considered much cleaner than Ladoga.
The lake has long been called Onego, and there are still disputes about the origin of its name. Many believe that the reservoir got its name from the ancient Finnish language, and means “smoking lake”, since strong fogs have become a frequent occurrence in this place. According to another version, Onego is a noisy lake, according to a third version, the name means "big, significant." There is also a version that the lake got its name from one of the 50 rivers that flow into it. But most likely, this river got its name from the lake. Curious is the fact that only one river flows out of Onega - the Svir, which carries its waters to the great Ladoga.
Lake Onega is rich in islands, there are more than 1500 of them. The shores of the islands are indented with bays and bays, they give Onega a peculiar charm and picturesqueness. And a number of rocky capes, polished by the glacier and the Onega wave, became sheets of a stone book, on which ancient man more than four thousand years ago he kept a chronicle of his life. Petroglyphs of Lake Onega, depicting men, birds, lizards, tools, boats, deer, swans, fish and some mysterious signs, in the form of mysterious circles and lines, are located for the most part on the east coast.
The ichthyofauna of Lake Onega is very diverse, there are more than 47 species of fish here: from bream and crucian carp to trout and salmon. Therefore, fishing has become one of the main types of recreation in the Onega region. Lake Onega is also very popular among yachtsmen. The festival of wooden ships "Blue Onego" and the All-Russian sailing regatta of cruising yachts "Onego" are held here.
See video: Fishing trips - fishing on Lake Onega. part 1
Part 2
The main attraction of the lake is Kizhi Island, where the State Historical, Architectural and Ethnographic Museum-Reserve is located. And the Kizhi churchyard, consisting of the twenty-two-domed Church of the Transfiguration of the Lord, the nine-domed Church of the Intercession of the Virgin and the hipped bell tower, has long been calling card Karelia.
See where Onega is located on the map:
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Lake Onega is the second largest lake in Europe. In terms of an area equal to 9900 km 2, it ranks fourth among big lakes Russia. Its maximum depth does not exceed 120 m. The main tributaries of Lake Onega are Shuya, Suna and Vodla. River flows out of it. Svir.
Lake basin of tectonic origin; it was largely reshaped as a result of the activity of the glacier. The influence of the work of glaciers is especially noticeable in its northern part, which is distinguished by the indentation of the coastline: there are many narrow bays deeply protruding into the land, elongated from northwest to southeast, i.e. in the direction of movement of the glacier.
The relief of the lake bottom is characterized by a complex structure and extreme uneven distribution of depths. This Lake Onega, as well as Ladoga, stands out sharply from other large lakes in the world. Approximately along the line Petrozavodsk - the mouth of the Vodla, the lake basin is divided into two sharply different parts: northern and southern. South part it has a flat bottom topography and relatively shallow depths. Here, in turn, several morphologically distinct parts can be distinguished: 1) Svir Bay, 2) Svir Onego, 3) Southern Onego and 4) Central Onego.
The northern part of the lake basin is characterized by extremely sharp fluctuations in depths, the presence of numerous long and deep depressions or pits separated by elevated sections of the bottom. A large number of shoals, capes, islands and bays gives this part of the lake an skerry character. Separate parts of the lake have independent names: Big Onego, Petrozavodsk Bay, Kondopoga Bay, Lizhma Bay, etc. The largest bay in the northern part of the lake is Povenetskaya, it has a length of about 100 km.
The northern coast is rocky, while the southern, eastern and western coast mostly formed by a chain sand dunes reaching a height of 15-18 m in places, behind which swamps are sometimes located. The entire deep-water part of the lake basin is filled with light gray-green silts, and the shallow coastal parts of the lake are filled with wood, pebbles and boulders.
The amplitude of fluctuations in the lake level is small and amounts to 50-55 cm per year; its long-term values are 1.8-1.9 m depending on the nature of the weather in a given year. different type the annual course of the water level, however, for the most part, the course of the level corresponds to the type of regime with a distinct, albeit low, spring flood. In the secular course of the lake level, a certain cyclicity is observed, which is in good agreement with the course of atmospheric precipitation.
It is interesting to note that in 1854 engineer Stabrovsky recorded seiches on Lake Onega for the first time in Russia. This was done many years before the seichi Lake Geneva began to be studied by Trout.
The water balance of Lake Onega on average over a long period (1887-1939) according to calculations made by 3.A. Vikulina; characterized by the following data (Table 1).
Table 1. Water balance of Lake Onega
The transparency of the lake water is relatively low, less than in Lake Ladoga. The white disk, lowered into the water, usually ceases to be visible at a depth of 4 m. The water of the lake in the mass has a slightly brownish color due to the large influx of swamp waters; its mineralization is very weak and amounts to 30-40 mg / l, and its hardness is not more than 1 German degree. Highest values(17°) water temperature reaches in August; in the bottom layers, even in the hottest periods, the temperature is not higher than 4 °. In the warm part of the year, the shock layer is well expressed and is located at a depth of 20–25 m.
The process of freezing of Lake Onega begins from the coastal shallow parts and gradually captures the central deep water areas, which are covered with ice much later due to large stock heat in the water and excitement; this process lasts about 1.5-2 months - from mid-November to the end of January. Clearing the lake of ice begins in the southern part of the reservoir in mid or late April. Most of the lake is opened in the first decade of May, and the central part - in the middle of this month. Lake Onega is part of the White Sea-Baltic waterway and is the regulator of the Svir flow, the water energy of which is used for hydroelectric purposes.
