The Ladoga Lake is the largest lake in Europe. Total area of The Ladoga Lake is 18135 square kilometers, and 457 of them are islands.
There are over 650 islands which area exceeds 1 hectare and about 500 of them are located near north-west shore. The intricate shapes of the rocky islands that run up to 60-70 meters go with indented shoreline that cut deep by numerous bays. The lake is inexhaustible source of drinking water for the second largest city of Russia – Saint Petersburg.
The nature worked at the artistic appearance of The Ladoga Lake for many millions years. Its northern part is located on the Baltic shield which formation dates from the ancient ages of the Earth's evolution. The Shield's rocks are mainly granite, gneiss, crystalline shale of so-called Archaean age. These rocks appear on the surface and only rarely covered with thin layer of later ages' rocks.
From the plumb shores of the northern part of the lake one can see the delightful panoramic view of little islands rise over the lake's silver surface. Figures show the indentation well: skerries area takes 790 kilometers out of total shoreline, which is 1570 kilometers.
32 rivers run to the Ladoga. It is the full-flowing Svir that keeps a huge source of energy, it is small, winding among forests and meadows, rivers of the northern shore, it's the straightforward Volhov, it's the Vuoksa that flows through many lakes. There are rivers, which sources located 20-40 kilometers from the Ladoga. Others keep flowing for few hundred kilometers.
All rivers of the Ladoga are different size but all of them serve as a main feeding source for the lake. The rivers bring about 70 cubic kilometers of water annually. In some years this figures can grow up to 100. Rain and snow that participate in filling up the lake take 15% from total tributary, the ground waters – only 2%.
Resource of the Ladoga is 908 cubic kilometers. It is not stable: in some periods it grows, in other – it drops. However, the fluctuation never exceeds 6% of total volume of water at least the last 100 years.
In ancient times the long period of low water level often was explained by supernatural powers. The inhabitants of the shores had different legends.
There was a belief that the water level of the Ladoga grows for 7 years and then drops for 7 years (the probable reason is the number 7 is considered to be the lucky one). Periods of low water level was considered to be bad event. At the 18-19 centuries, it had strong influence to Saint Petersburg's life, which economical development was associated with shipping. At those periods, the shipping was difficult and suffered damage. Transportation of goods was decreasing, prices were growing, and that caused the troubles for the poor first.
Since ancient times shipping in the lake was very risky. Thousands of ships had crushed in its waves. That became a reason why all insurance companies refused to insure the ships sailing with cargo. It was not only poor equipment of ships and lack of good navigation but also natural features of the Ladoga. The famous explorer A.P. Andreev wrote: "The Lake is stormy and filled with stones".
The reason of the Ladoga's severe temper is special structure of its basin, distribution of depths and shapes of the Lake. Keen fracture of the floor that changes from deep waters of the northern part to shallow waters of the south part prevents from formation of the "regular" waves across whole length of the Lake.
Such a wave can appear only in northern part. Being blown by the winds to the south it keeps its shape only under deep waters. As soon as it comes to area of 15-20 meters depths it breaks. It becomes high but brief. Its crest drops. A compound system of waves arises and runs in different directions; that is so-called "crowd". It is especially dangerous for small ships that suffer from a sudden and powerful jolt.
There was another one feature of waving at the Lake noticed. The waves alternate at the time of the storm – a group of 4 or 5 high and long waves change to a group of more low and brief ones. A ship takes this phenomenon as a bumpy road. It causes a rolling that negatively affects on the hull. Exploration of the waving on the Lake is quite difficult. The highest wave that was measured reached 5,8 meters. It is supposed to be higher at the time of the storm.
There are 58 fish species including five species settled by a man at the Ladoga. Probably the most valuable fish of the Ladoga are salmon of seven species. Except of entering sea salmon the Ladoga is full of lake salmon and lake trout.
Travelers who hike the Ladoga often see seals that look out from the water not far from motor ship. Seal is the only mammal that constantly lives in the Ladoga waters. More then 10 hundred years ago its ancestry came from White sea hollow to Karelian glacial sea that became the Ladoga lake later.
Animals acclimatized in the new reservoir and now they are quite common in the Ladoga. Seals like to sun themselves on a shore rocks. They funny scratch themselves. One can see them often floating on a log.
The last but not least animal that should be mentioned is a dolphin that occasionally comes from the Baltic Sea to the Neva and the Ladoga Lake.
Translated by Ekaterina Zharova.