Lake Ladoga, Russia

Description of Lake Ladoga

Lake Ladoga is located in the North-West of Russia. Its northern part is located in Karelia, and the southern - in the Leningrad region.

Lake Ladoga is the largest in Europe. The lake area is over 18 thousand square meters. km, and depth reaches 200 m. The greatest length of the lake from north to south - 219 km. Many small and medium-sized rivers flow into the lake, among which the largest are the Svir, Olonka, Syas and Volkhov. Only the Neva flows out of the lake, the source of which is located near the town of Shlisselburg. There are about 600 islands on Ladoga, mainly in the northern part, of which the Valaam archipelago is most famous.

Lake Ladoga often stormy. For the passage of river vessels, that are not adapted to the harsh lake conditions, along the southern shore of the lake, the Novaya Ladoga Canal was dug that is 169 km long.

The southern shores of Ladoga are low-lying and marshy, while the northern shores are rocky and steep. Ladoga granite and other rocks of building stone, used in particular in the construction of St. Petersburg, are mined there.



In the ancient Russian Nestor chronicle of the 12th century, it is referred to as the “great lake Nevo” (there is no doubt a connection with the name of the Neva River (also compare Fin. neva “swamp, bog”)). In the ancient Scandinavian sagas and agreements with the Hanseatic cities, the lake is called Aldoga.

From the beginning of the 13th century, the name Ladoga Lake came into use, formed from the name of the city of Ladoga, which in turn was named after the tributary of the same name in the lower reaches of the Volkhov River, from Fin. alodejoki - "river in low country". Other variants of the origin of the name of the lake: from the Karelians. aalto - "wave", hence the Karelian. aaltokas - "wavy"); from the dialectal Russian word alod, meaning an open lake, a vast water field.

The name Ladoga is given to a river, a lake and a city. At the same time, until recently it was not quite clear which of the names is primary. The name of the city was derived from the name of Lake Ladoga (from Finnish *aaldokas, aallokas "wavering" - from aalto "wave"), or from the name of the Ladoga River (now - Ladoga, from Finnish * Alode-joki, where alode, aloe - " low terrain" and jok(k)i - "river").

As T. N. Jackson writes, “by now it can be considered almost proven that the name of the river first arose, then the city, and only then the lake.” Therefore, she considers the primary hydronym Ladoga, from Fin. *Alode-jogi (joki) "lower river". From the name of the river came the name of the city of other Scandinavian. Aldeigja, and it was already borrowed by the Slavic population and transformed with the help of the ald → lad metathesis into Old Russian. Ladoga. The Scandinavian mediation between the Finnish and the Old Russian word is fully confirmed by archeological data: the Scandinavians first appeared on Ladoga in the early 750s, that is, a couple of decades earlier than the Slavs.

E. A. Khelimsky, on the contrary, offers a Germanic etymology. In his opinion, the name of the lake is primary - from other Scandinavian. * Aldauga "old reservoir". This hydronym is associated with the name of the Neva (which flows from Lake Ladoga) in the Germanic languages - "new". Through the intermediate form *Aldaugja, this word gave another scand. Aldeigja "Ladoga (city)".


Physical and geographical characteristics

The history of the formation of the lake
In the Paleozoic, 300-400 million years ago, the entire territory of the modern basin of Lake Ladoga was covered by the sea. Sedimentary deposits of that time - sandstones, sands, clays, limestones - cover with a thick layer (over 200 m) a crystalline basement consisting of granites, gneisses and diabases.

The northern part of Lake Ladoga lies on the Baltic Crystalline Shield, the southern part lies 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 modern relief was formed as a result of the activity of the ice sheet (the last, Valdai glaciation ended about 12,000 years ago). The main factors were the gradual rise in the level of the world ocean, changes in the level and regime of reservoirs that existed in the basin of the Baltic Sea in the Holocene, the flow of water from the melting glacier and its weight - the rise of land began (and continues).

The southern part of the Ladoga Basin was freed from ice about 14,000 years ago. Initially, on the liberated territory there was an independent near-glacial lake with a drain into the Baltic Glacial Lake. As the level of the Baltic glacial lake rose, Ladoga became part of it no later than 13,300 years ago. In the early stages, the basins were connected in the area of the Neva lowland. After the liberation of the northern part of the Karelian Isthmus from the glacier about 12,200 years ago, the lakes began to communicate through a wide strait in the north of the modern isthmus - the so-called Heiniok Strait. The strait in the area of the Prinevskaya lowland, gradually narrowing, existed until the descent of the Baltic glacial lake. Glacier retreat in central Sweden opened straits in the region of present-day Mount Billingen about 10,300 years ago, causing the Baltic Glacial Lake to sink 25–28 meters to sea level in just a few years.

During the Yoldian stage of the evolution of the Baltic Basin (10,300–9,500 years ago), Ladoga remained a lake, the flow from which was carried out through the territory previously occupied by the Heinioka Strait. The area of the lake has decreased significantly, especially in the southern part.

With the onset of the Ancylus stage 9500 years ago, the level of the Baltic Basin rises by 15–20 meters, which leads to the reunification of the basins through the Heinioka Strait. The continuing rise in the level of Lake Antsylovoe caused the transgression of Lake Ladoga about 9300–9200 years ago, which was especially pronounced in the southern part of the modern basin. The appearance of the Dana River in the region of the present-day Great Belt caused a gradual drop in the level of Lake Ancylus, which reached sea level about 9,000 years ago. Around this time, Ladoga again separates from the Baltic basin, and its level drops significantly below modern levels. The Heiniok Strait dries up and modern lakes appear in the north of the Karelian Isthmus.

It is generally accepted that in the period from 9000 to 5000 years ago, the runoff from Lake Ladoga occurred in the Vyborg Bay through the channel system of the lake-river system of Vuoksa. The runoff threshold was located in the area of the village of Veshchevo.

Between 5700 and 5000 years ago, the waters of Lake Saimaa broke through the Salpausselkya-I ridge in the Imatra region, forming a modern runoff channel to Ladoga through the Vuoksa system and significantly increasing the lake's drainage basin.

About 5000 years ago, the level of Lake Ladoga began to rise, the causes of which are usually associated with an increase in the incoming part of the lake's water balance after the accession of the Saimaa system. The subject of discussion is the mechanism of runoff from Lake Ladoga in the period between the formation of the modern runoff direction in the Vuoksa system and the appearance of the Neva. The Ladoga transgression, judging by the soil profile 1 in Staraya Ladoga, took place 5700–3400 years before the present.

The uneven isostatic uplift of the northern and southern parts of the lake led to the "overturning" of the basin of Lake Ladoga in a southerly direction. In the Neva lowland at that time there were the Mga rivers, the mouth of which was located at the site of the modern source of the Neva, and the Tosna, which flowed into the Gulf of Finland, separated by a watershed in the area of \u200b\u200bthe modern Ivanovsky rapids. The rise in the level in the southern part of Ladoga led to the flooding of the Mga valley and the erosion of the Mginsko-Tosnensky watershed about 2500 years ago (according to other estimates - from 4500 to 1200 years ago). During the subsequent deepening of the valley, the modern channel of the Neva was formed. The level of the lake after the formation of the Neva fell by 12-13 meters.


Meteorite crater in Lake Ladoga (Ladoga astrobleme)
In the 2000s, it was suggested that Lake Ladoga is of meteorite origin. The northern, deep part is the crater of the explosion, and the rest, the shallow part, was formed at the site of the subsidence caldera. In favor of the meteorite origin are signs of shock-explosive melting and vitrification of rocks, as well as the presence of erupted basalts (or tagamites). It is believed that the crater arose approximately 38.5 thousand years ago and is about 80 km in diameter. The calculated parameters of the celestial body that gave rise to it: size - 11 km in diameter, speed - 17 km / s.

The climate over Lake Ladoga is temperate, transitional from temperate continental to temperate maritime. This type of climate is explained by the geographical location and atmospheric circulation, which is typical for the Leningrad region. This is due to the relatively small amount of solar heat entering the earth's surface and into the atmosphere.

Due to the small amount of solar heat, moisture evaporates slowly. There are an average of 62 sunny days per year. Therefore, for most of the year, days with cloudy, overcast weather and diffused lighting prevail. The length of the day varies from 5 hours 51 minutes at the winter solstice to 18 hours 50 minutes at the summer solstice. The so-called "white nights" are observed over the lake, coming on May 25-26, when the sun drops below the horizon by no more than 9 °, and the evening twilight practically merges with the morning. The white nights end on July 16-17. In total, the duration of the white nights is more than 50 days. The amplitude of the average monthly sums of direct solar radiation on a horizontal surface in a clear sky is from 25 MJ/m² in December to 686 MJ/m² in June. Cloudiness reduces, on average per year, the arrival of total solar radiation by 21%, and direct solar radiation by 60%. The average annual total radiation is 3156 MJ/m².

The lake itself has a significant impact on climatic conditions. This is characterized by the smoothing of extreme values of climatic characteristics, as a result of which the continental air masses, passing over the surface of the lake, acquire the character of maritime air masses. The average air temperature in the area of Lake Ladoga is +3.2 °C. The average temperature of the coldest month (February) is −8.8 °C, the warmest (July) is +16.3 °C. The average annual rainfall is 475 mm. The smallest monthly amount of precipitation falls in February-March (24 mm), the largest - in September (58 mm).

During the year, western and southwestern winds prevail in most of Lake Ladoga. The average monthly wind speed in the open part of the lake and on most of the islands from October to January-February is 6-9 m/s, in the remaining months 4-7 m/s. On the coast, the average monthly wind speed varies from 3 to 5 m/s. Calms are rarely observed. In October, storm winds with a speed of more than 20 m/s are often observed on Lake Ladoga, the maximum wind speed reaches 34 m/s. Breezes are observed along the entire coast in summer on windless sunny days and clear nights. The lake breeze begins at about 9 am and lasts until 8 pm, its speed is 2-6 m/s; it extends 9-15 km inland. Fogs are observed most often in spring, late summer and autumn.

Shores, bottom topography and hydrography of the lake
The area of the lake without islands is from 17.6 thousand km² (with islands - 18.1 thousand km²); length from south to north - 219 km, maximum width - 138 km. The volume of the water mass of the lake is 908 km³. This is 12 times more than is annually poured into it by rivers and carried out by the Neva River. Seasonal fluctuations in the water level in the lake are small due to the large area of the water surface of this reservoir and the relatively small annual variation in the amount of water entering it. The latter is due to the presence of large lakes within the watershed of Lake Ladoga and the presence of hydropower facilities on all major tributaries, which together provide a fairly uniform flow of water throughout the year.

The coastline of the lake is more than 1000 km. The northern shores, starting from Priozersk in the west to Pitkäranta in the east, are mostly high, rocky, heavily indented, form numerous peninsulas and narrow bays (fjords and skerries), as well as small islands separated by straits. The southern shores are low, slightly indented, flooded due to the neotectonic submeridional skew of the lake. The coast here is replete with shoals, rocky reefs and banks. In the southern half of the lake there are three large bays: Svirskaya, Volkhovskaya and Shlisselburgskaya bays. The eastern shore is not very indented, two bays protrude into it - Lunkulanlahti and Uksunlahti, fenced off from the side of the lake by one of the largest islands of Ladoga - Mantsinsaari. There are wide sandy beaches. The west coast is even less indented. It is overgrown with dense mixed forest and shrubs, coming close to the water's edge, along which there are scatterings of boulders. Ridges of stones often go far from the capes into the lake, forming dangerous underwater shoals.

The relief of the bottom of Lake Ladoga is characterized by an increase in depth from south to north. The depth varies unevenly: in the northern part it ranges from 70 to 230 m, in the southern part - from 20 to 70 m. The average depth of the lake is 50 m, the greatest is 233 m (to the north of Valaam Island). The bottom of the northern part is uneven, furrowed with depressions, while the southern part is calmer and more smooth. Lake Ladoga ranks tenth among the deepest lakes in Russia.


Basin and islands

35 rivers flow into Lake Ladoga. The largest river that flows into it is the Svir River, which brings water into it from Lake Onega. Water also enters the lake through the Vuoksa River from Lake Saimaa, and through the Volkhov River from Lake Ilmen. The rivers Morie, Avloga, Burnaya, Kokkolanjoki, Soskuanjoki, Iijoki, Tohmajoki, Janisjoki, Syuskyuyanjoki, Uksunjoki, Tulemajoki, Miinalanjoki, Vidlitsa, Tuloksa, Olonka, Obzhanka, Voronezhka, Syas, Lava, Ryabinovka, Naziya and others also flow into it. The Neva is the only river flowing from Lake Ladoga.

The catchment area is 258,600 km². Approximately 85% (3820 mm) of the incoming part of the water balance comes from the inflow of river waters, 13% (610 mm) from atmospheric precipitation and 2% (90 mm) from the inflow of groundwater. About 92% (4170 mm) of the expenditure part of the balance goes to the Neva runoff, 8% (350 mm) to evaporation from the water surface. The water level in the lake is not constant. Its fluctuations are clearly visible in a lighter stripe on the surface of the rocks that go into the water.

There are about 660 islands on Lake Ladoga (more than 1 ha in area) with a total area of 435 km². Of these, about 500 are concentrated in the northern part of the lake, in the so-called skerry region, as well as in the Valaam (about 50 islands, including the Bayevye islands), the Western archipelagos and the Mantsinsaari group of islands (about 40 islands). The largest islands are Riekkalansaari (55.3 km²), Mantsinsaari (39.4 km²), Kilpola (32.1 km²), Tulolansari (30.3 km²) and Valaam (27.8 km²).

The most famous on Lake Ladoga are the Valaam Islands - an archipelago of about 50 islands with an area of \u200b\u200babout 36 km², due to the location of the Valaam Monastery on the main island of the archipelago. Also known is the island of Konevets, on which the monastery is also located.