The basin of Lake Ladoga is of glacial-tectonic origin. In the Paleozoic 300 - 400 million years ago, the entire territory of the modern Lake Ladoga basin was covered by the sea. The sedimentary deposits of that time are sandstones, sands, clays, limestones - they cover a thick thickness (over 200 m) of a crystalline foundation consisting of granites, gneisses and diabases.

The modern relief was formed as a result of the activity of the ice sheet (the last Valdai glaciation ended about 12 thousand years ago). The main factors were: changes in the level of the world's oceans, the water of the glacier and its weight - the rise of the land began (and continues). After the glacier retreated approximately 12,600 years ago, the fresh Baltic Glacial Lake was formed with a level of 25 meters above the ocean. About 10-9.6 thousand years ago, the waters of the lake broke through in the area of ​​​​central Sweden and the Yoldian Sea was formed, the level of which was 7 - 9 m higher than the modern level of the Baltic Sea.

Approximately 9,500 years ago, rising land blocked the strait in central Sweden and Lake Ancylus was formed. In the north of the Karelian Isthmus, it was connected by a wide strait to Lake Ladoga. The Mga River at that time flowed east and flowed into the lake near the modern source of the Neva.

Approximately 8,500 years ago, tectonic processes open the Danish Straits and the Littorina Sea is formed. The water level, although significantly higher than the current one, was less than in Lake Anzilov. This led to the formation of the Karelian Isthmus and the formation of Lake Ladoga.

How long the lake was completely isolated is unknown - the water level in the lake rises faster than the rise of the land, and when the level of Ladoga exceeded the watershed level, the lake waters, flooding the valley of the Mgi River, broke into the valley of the Tosna River.

Thus, approximately 4 thousand years ago, a new strait arose between Lake Ladoga and the Gulf of Finland, which became the valley of the Neva River. The old strait in the north of the Karelian Isthmus by this time was already above the lake level. Over the past 2.5 thousand years, the relief has not changed significantly.

The northern part of Lake Ladoga lies on the Baltic crystalline shield, the southern part on the East European Platform. In the areas closest to Ladoga, the southern border of the shield runs approximately along the line Vyborg - Priozersk - the mouth of the Vidlitsa River - the source of the Svir River.

The crystalline foundation of the Northern Ladoga region belongs to the ancient primary foundation of Fennoscandia and was formed about 2000 million years ago. These are the oldest geological formations on Earth. Over millions of years, the ancient Svekokarelid Mountains have been flattened into picturesque hills, cliffs and cliffs. The depression of Lake Ladoga was formed in the Tertiary period as a result of a powerful geological fault. At the same time, as a result of faults, the formation of the archipelago and the coastal part of the northwestern shore of Lake Ladoga occurred. 12 thousand years ago, after the departure of the glacier, almost the entire surface of the Ladoga region was under the water of the ancient Baltic glacial lake. The climate, water level and salinity of the lake gradually changed. About 4000 - 3000 years ago, the Neva was formed and the level of Lake Ladoga dropped by 10 meters.

At the end of the 9th century AD. a change in the hydrography of the region (a decrease in the level of the Baltic and, accordingly, Lake Ladoga) led to a simultaneous process of shallowing of the rivers of the Ladoga basin, including the Volkhov and its tributaries.

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rice. 4 Ancylus Lake includes Ladoga 9500 years ago. The lake's flow into the ocean is indicated.

32 rivers - more than 10 km long - flow directly into Lake Ladoga; the largest rivers flowing into Lake Ladoga include: r. Svir flowing from Lake Onega, river. Vuoksa, originating in Finland, r. Volkhov, flowing from Lake Ilmen, river. Syasya and others.

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rice. 5 Svir River - Podporozhsky district in the northeastern part of the Leningrad region.

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rice. 6 Svir River, rapids.

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rice. 7 Sandy banks of the Svir River.

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rice. 8 Vuoksa River.

The Vuoksa River is mentioned in the Novgorod Chronicles. People have lived in the vicinity of the river since prehistoric times - sites from the Stone Age period have been discovered here; Vuoksa is mentioned in the ancient epic “Kalevala”. In the distant era of Tsar Ivan the Terrible, the Vuoksa River is mentioned as a place of congress to resolve state issues.

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Fig. 9 Vuoksa near Melnikovo.

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rice. 10 A dam on the Vuoksa River in Imatra.

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rice. 11 Priozersk Vuoksa River.

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rice. 12 Upper reaches of the Volkhov River.

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rice. 13 Volkhov River in the area of ​​St. Ladoga and Lyubsha (Chernavino-5), mounds in the “sopka tract”.

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rice. 14 Volkhov River - not far from the mouth.

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rice. 14 Syasya river.

Lake Ladoga - Nevo.

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rice. 16 ladozhskoe lake.

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rice. 17 Landscapes of Lake Ladoga.

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rice. 18 Lake Ladoga - shores.

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rice. 19 Lake Ladoga - breakers.

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rice. 20 Lake Ladoga - forest.

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rice. 21 Lake Ladoga - silence.

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rice. 22 Lake Ladoga - autumn.

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rice. 23 Rocky shores of Lake Ladoga.

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rice. 24 Lynx Rock, village. Vyartsilya, Northern Ladoga region.

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rice. 25 Ruskeala, former marble quarry. Rock height: 30 - 40 m, Northern Ladoga region.

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rice. 26 Lake Ladoga - stones.

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rice. 27 Boulder near Vidlitsa - a river in Karelia, Ladoga region.

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rice. 28 On the islands of Lake Ladoga.

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rice. 29 Cape Rahaniemi. Radiance August 18, 2003.

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rice. 30 Gorskii Staraya Ladoga Canal photo 1909

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Fig. 31 Korela Fortress in Priozersk.

Korela (Swedish Kexholm, Finnish Käkisalmi "Cuckoo Strait") is a stone fortress in the city of Priozersk, on an island in the Vuoksa River. Medieval Korela was the most northwestern city of Rus'. The fortress was founded at the turn of the XIII and XIV centuries. Novgorodians on the island of the Uzerve River(Vuokse)to protect the northwestern borders of the republic from the Swedes.

Priozersk - [Karelian. Kägöisalmi, Finnish Käkisalmi - “Cuckoo Strait”, Swedish. Kexholm - “cuckoo island”] is the administrative center of the Priozersky district of the Leningrad region. The city is located on the Karelian Isthmus, along the banks of the northern branch of the Vuoksa River, between Lake Ladoga and Lake Vuoksa. Until the beginning of the 17th century, it was the center of the Korelsky land, the Korelsky district of the Vodskaya Pyatina. From the 14th century to 1611 the city was known as Korela. From 1580 to 1595 and from 1611 to 1918 the city was called Kexholm. Since 1918, the city, as part of the newly independent Finland, began to be called Käkisalmi. In 1940, after the Soviet-Finnish war, the city became part of the Soviet Union, and the name Kexholm was returned. In 1941-1944, during the Soviet-Finnish War, the city was occupied by Finnish troops and was called Käkisalmi. In 1944, after the Moscow Armistice, the city became part of the Soviet Union for the second time. In 1948 it was renamed Priozersk.)

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rice. 32 Fortress Oreshek - Orekhovy Island, (Finnish: Pähkinäsaari) - a small island at the source of the Neva. The main attraction is the ancient Novgorod fortress of the 14th century Oreshek.

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Fig. 33 Map of the Brockhaus and Efron encyclopedia. Ladoga lake. (clickable)

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There is a reservoir that amazes with its history and grandeur. The largest in Europe and one of the 20 largest in area in the world is Lake Ladoga. It is so huge that in ancient times the Scandinavians and Slavic tribes called it the sea. It is so unique that now we can rightfully consider it one of the most precious natural objects in Russia.

Without taking into account the islands, the water surface of the lake covers more than 17,500 square meters. km, and with the islands - 18,100. The length of the lake from south to north is 219 km, from west to east - up to 138 km. The length of the coastline is more than 1000 km. The depth varies from 20 to 230 m, with the northern part being noticeably deeper than the southern part. This is due to differences in natural conditions. The northern part, Karelian, is located within the Baltic Shield, the coast here is high and rocky, with many straits and islands. The southern one is located in an area with loose sedimentary rocks and is much less rugged. There are many shallows and sandy beaches.

CHILDREN OF THE GLACIER

Lake Ladoga has a complex history. Its basin was formed mainly due to the activity of the glacier. About 12,500 years ago, on the site of the present Baltic Sea and part of the surrounding lands, a huge fresh lake appeared as a result of the melting of a glacier. Several times it was either connected to the World Ocean by straits as a result of overflowing with water, or again found itself isolated due to the rise of the land after the glacier pressure was removed from it (by the way, this process is still ongoing). As a result, the lake finally connected with the ocean through straits between the shores of modern and. The water level in it began to fall, which means the coastline was retreating. In its northern part, the Karelian Isthmus formed, fencing off part of the former large lake - Lake Ladoga. For some time the new reservoir existed in isolation. But the water level in it rose faster than the rise of the land, as a result of which about 4000 years ago the waters of the lake broke through to the sea, forming a short but very deep river - the Neva.

RIVERS AND ISLANDS

More than 35 rivers flow into Lake Ladoga, 3 of which are of particular importance. The fact is that these rivers carry the waters of three more large lakes into it. The first, largest, Svir, flows from Lake Onega. Through Vuoksa, Lake Ladoga connects with Lake Saimaa in, and through the majestic Volkhov - with the legendary Ilmen, the “Slovenian Sea”, near which Veliky Novgorod stands.

Lake Ladoga is a flowing lake, with only one river flowing out of it - the Neva. With a length of only 74 km, this river is one of the deepest in Europe. And all thanks to the huge drainage basin of Lake Ladoga, whose area is 258,600 square meters. km. 85% of water enters Lake Ladoga from rivers, 13% from precipitation and 2% from groundwater. At the same time, 92% of the moisture leaving the lake falls on the Neva, and 8% is due to evaporation from the surface. It is important to note that the water level in the lake is not constant. The way it changes can be seen in the traces left on boulders and rocks that go into the water.

There are more than 650 islands on the lake, most of them are concentrated in its northern part - the skerry area. Skerries are a group of small rocky islands, sometimes with high or almost vertical shores. In the northern half of the lake there is also the famous Valaam archipelago with the famous monastery on the main island. Depending on the size and history of the island, it can be covered with forest, sparse vegetation, or completely deserted. In the south and southwest of the lake in the coastal zone there are huge thickets of moisture-loving species - primarily cattails and reeds.

LADOGA OLD-TIMEERS

Relatively few nutrients are dissolved in the waters of Lake Ladoga. This, as well as fairly low temperatures, significant depths and strong waves, cause the reservoir to be somewhat poorer than what could be expected. There are 120 species of higher aquatic species found here. They reach the greatest diversity in the reed-reed strip up to 10 m wide. There are more than 350 species of algae in the lake.

More than 370 species of planktonic organisms live here. In addition, the lake contains various types of mollusks, worms, water mites, crustaceans, etc. The main vertebrate inhabitants are fish. There are more than 50 species and subspecies. Along with the well-known chub, rudd, roach, pike or perch, there are truly rare trout, palia, Atlantic sturgeon and Volkhov whitefish. The last two species are included in the Red Book of Russia. For whitefish, the main threat, as for a number of other organisms in the lake, is the hydroelectric power station built near the mouth of the Volkhov, which prevents the movement of fish to the upper reaches of the river. More than 250 species of birds are found on the lake and in the surrounding area, some of them form large gatherings here on migration.

Lake Ladoga is one of three on the planet where seals are found. In addition to it, seals live in Lake Saimaa and Baikal. The ringed seal lives in Ladozhskoe.

CONTRIBUTION OF CIVILIZATION

Unfortunately, Lake Ladoga has quite a few environmental problems, some of which are very acute. Thus, on one of the islands after the Great Patriotic War, experiments were carried out with radioactive substances, which led to the contamination of part of the territory and water area. Until the mid-1990s, explosives and toxic substances were being developed on another island. A particularly large contribution to the pollution of the reservoir is made by industrial production located on its banks or nearby (metallurgical plants, pulp and paper mills, etc.). A significant portion of them discharge wastewater directly into the lake or its tributaries, while very few enterprises have modern wastewater treatment systems.

IT IS IMPORTANT TO KNOW

If in the 1970s the waters of Lake Ladoga, according to current standards, were among the purest and characterized by quality class I, today the lake is considered a moderately polluted reservoir of class III.

The reservoir that existed for some time on the site of the present Baltic Sea and Lake Ladoga was called the Ioldian Sea - after the name of the arctic mollusk Ioldia, the remains of which are found en masse in sedimentary rocks of that time. Such organisms, by the presence of which a rock can be attributed to a particular period, are called leading fossils (forms) in geology.

Lake Ladoga is located in northwestern Russia.

Lake Ladoga has an ancient history, unique nature and a rich natural world.

Its shores, islands and waters are important for the development of the economy and tourism of the region. This is the largest European freshwater lake.

How the lake came into being

It is believed that for hundreds of millions of years there was a sea on the site of modern Lake Ladoga. Its modern appearance is the result of the movement of the glacial cover.

Researchers believe that the basin on which the lake arose began to become free of ice about 14 thousand years ago. First, a periglacial lake arose, which drained into a glacial lake, on the site of which the Baltic Sea later arose.

Over the next several thousand years, the water level in the lake and its surface area changed repeatedly. Later, as a result of a change in the bottom profile, the lake basin was oriented to the south.

The bed of the Neva in its modern form gradually formed. After the formation of this river, the water level in the reservoir, which belongs to the Baltic basin, decreased by 12-13 meters.

Historical events

On the southern part of its coast in the 8th century the city of Ladoga was founded, which gave the name to the lake. It played an important role in the Varangian waterway from Scandinavia to Byzantium, which was opened in the next century. In the 13th century, the name Lake Ladoga became commonly used. In 1617, after Russia was defeated in the war with the Swedes, most of the lake coast and coastal fortresses and settlements went to the Swedes.

At the beginning of the 18th century, as a result of the Northern War, which was victorious for Russia, the shores of the lake became completely Russian. After this, shipping canals were built. During the Great Patriotic War, most of the Ladoga coast was occupied by German and Finnish troops. To maintain connections between Leningrad, blocked by the Nazis, and the unoccupied part of the Soviet state, the “Road of Life” was organized from the autumn of 1941 to the spring of 1943.

Navigating by ships and cars on strong ice, over one and a half million tons of food and other goods were delivered to the city, and over 1.3 million city residents were evacuated. The ships of the Ladoga military flotilla, created at the beginning of the Soviet-Finnish war, played an important role here.

Ladoga lake. road of life photo

The islands located on the lake left a big mark on the history of Ladoga. The island of Valaam with its Spaso-Preobrazhensky Monastery, founded in the 10th-11th centuries, gained worldwide fame. According to legend, the holy Apostle Andrew the First-Called crossed the path from Kyiv and Novgorod. When he reached the island, he blessed it with a cross. Prominent Russian architects took part in the construction of the monastery buildings.

On the small island of Konevets in the 14th century, the Monk Arseny founded the Nativity of the Mother of God Monastery.

Characteristics and natural conditions

Together with the islands, the area of ​​Lake Ladoga is 18.3 thousand square meters. km. It stretches from north to south for 219 km, with a width of 125 km. The lake is located 4.84 m above sea level. The shores of the lake, stretching for more than a thousand kilometers, have a varied and rich topography. On the southern coast they are not high, have many shallows, interspersed with reefs of stones and small bays. On this side of the lake there are three large bays.

Lake Ladoga, Valaam Island, Valaam Monastery photo

Its northern shores are predominantly rocky and high. There are many peninsulas, fjords and skerries, separated by straits of small islands. On the eastern side, two bays jut into the shore, fenced off by a large island. The coastal strip is relatively flat, with wide sand beaches. The western coast of Lake Ladoga is even more flat. It is distinguished by a dense forest approaching the water directly, formed by coniferous and deciduous trees, and a variety of shrubs. Along the shore there are frequent accumulations of boulders, which can form ridges into the water, creating a hazard for navigation.

There are a huge number of islands on the lake, of which 660 have an area of ​​more than a hectare and occupy about 435 square meters. km. More than half a thousand are located in the skerries area in the north of the lake. Dozens of islands form archipelagos, the largest of which is Valaam with 50 islands. Most of the islands are distinguished by high cliffs and steep shores. They may be covered with rich forest or have sparse vegetation.

The area of ​​Lake Ladoga has a specific climate, which has characteristics of temperate continental and temperate maritime. This is due to the characteristics of the region, expressed in. relatively small amount of heat from the sun reaching the earth and into the atmosphere. Throughout the year, only two months in total are sunny. Cloudy days with clouds and diffused light predominate throughout the year.

The average annual air temperature here is + 3.3 degrees. In February it is -8.8, and in warm July +16.3. From December to February the lake freezes. Its middle becomes covered with ice only at extremely low temperatures. In April-May it is freed from ice. Due to constant unrest, Lake Ladoga is not considered calm. Storms are common here, characterized by foam-covered waves reaching six meters in height. Sometimes phenomena of flow and surge of water mass occur, leading to changes in water level.

Flowing rivers, cities, ecology

The abundance of Lake Ladoga is ensured by the many rivers flowing into it, which provide about 85% of its water balance. Among them, the largest are the Svir, which flows from Lake Onega, the Volkhov, which originates in Lake Ilmen, and the Vuoksa, which connects Ladoga with Lake Saimaa. In total, 35 rivers and many streams carry their waters into the lake. Only the Neva, flowing from it, flows into the Baltic Sea. It accounts for about 92% of the lake's water flow.

city ​​of Priozersk fortress Korela photo

On the shores of the lake there are the following cities with Russian and Karelian names:

• Lahdenpokhya
• Novaya Ladoga
• Pitkäranta
• Priozersk
• Sortavala
• Shlisselburg.

These settlements are the centers of coastal economic life. The activity of their industrial enterprises is largely supported by lake shipping. The waterway from the Volga to the Baltic Sea passes through Ladoga. Millions of tons of cargo move across the lake every year. These are petroleum products and oil, building materials, chemical raw materials, etc. Tens of thousands of passengers are transported, including as part of tourist cruises.

Economic activities on the shores of the lake have led to pollution of the natural environment. Many enterprises, instead of effectively treating industrial waste, dump it into the lake and rivers flowing into it. Near the lake there are radiation and nuclear hazardous enterprises and testing grounds for radioactive components. As a result, contaminated areas have formed on some islands.

Ladoga skerries photo

In some areas of the water area, the content of dissolved heavy metals is seriously exceeded. Some coastal locations have high levels of toxicological and microbial contamination.

Animal world

Over 250 species of birds are found in the Lake Ladoga region. A fifth of them transit here every year in spring and autumn. According to ornithologists, Ladoga birds fly to Novaya Zemlya and Iceland, South Africa and India. Among them:

• geese
• ducks
• swans
• seagulls
• waders
• cranes and others.

Many other birds, including those belonging to rare species, arrange their nesting sites on the banks. On the southern coast, waterfowl nest in the reed thickets. There are a lot of freshwater fish in the lake. During the spawning period, she goes to spawn in the flowing rivers. In total, there are over fifty species of different fish, including the following:

• trout
• salmon
• zander
• perch
• pike and others.

About ten fish species are caught, among which ripus, vendace and smelt predominate. The most effective fishing is in the south of the lake at depths of up to 20 m. Sturgeon comes from the Baltic to spawn in the Volkhov and other rivers flowing into the lake through Ladoga along the Neva. Here they catch pike perch off the southern coast. In Volkhov and near the coast of the lake there are fish breeders of Siberian sturgeon, whitefish, trout, and other valuable fish.

Lake Ladoga and seagulls photo

However, the negative impact on nature reduces the population of valuable commercial fish, such as whitefish, trout, salmon, etc. The Volkhov whitefish and Atlantic sturgeon are included in the Russian Red Book. In addition, this book contains a unique seal, which is called the Ladoga ringed seal. The number of these animals in the lake does not exceed five thousand individuals.

• Every year on May 25-26 you can observe “white nights” over the lake, which last more than fifty days and end on July 16-17;
• in 2002, with the participation of domestic and foreign experts, an atlas of Lake Ladoga was published;
• the lake was first marked in 1544 on a map made by the German scientist S. Munster;
• Since 2002, a state register of ships, aircraft and other underwater objects located at the bottom of the lake has been compiled;
• after the war, experiments were carried out on some islands with chemical warfare agents and radioactive substances, and new types of weapons and explosives were developed
• in the 1970s, according to the standards of that time, the lake’s waters were the cleanest and were classified as quality class I, while today the moderately polluted water of the lake is assigned only class III;
• Among the deepest Russian lakes, Ladoga ranks eighth.