How pleasant it is to spend a weekend after a working week somewhere outside the city by the lake, away from the bustle of the city. For many, such a pastime is an integral part of relaxation. But do people really know how lakes are formed, how they can be useful, and how sometimes they can hurt?
What are lakes?
The lake is a closed depression in the ground, where underground and surface waters flow, which do not evaporate. Such a depression is called the lake basin. By origin, all lakes are divided into tectonic, river (elders), coastal, failed, underground.
According to salinity, fresh (Baikal), brackish (Chany) and salt lakes (Chad) are distinguished. All reservoirs can be drained when one or more rivers flow from the lake; flowing - several rivers flow into the lake and one or more flows out; closed - rivers only flow into the lake.
The filling of reservoirs occurs due to precipitation (rain, snow) or using groundwater. Also, lake food can be mixed.
According to the mineral composition of the lake there are carbonate, sulfate and chloride.
How are lakes formed?
Most of the lakes on our planet are of tectonic origin, that is, they formed in large troughs of the earth's crust or in rifts (tectonic cracks). The bottom of such a lake has a rough outline and is below sea level. Its shores are covered with hard rock, weakly amenable to erosion. All the deepest lakes are formed as a result of fractures of the earth's crust.
Many reservoirs are obtained as a result of geological processes (weathering, erosion, the activity of glaciers). Among them, the most common are glacial lakes on the plains and in the mountains, as well as failures, which were formed as a result of thawing of terrestrial rocks. Such reservoirs are round in shape. They are small in area and depth.
After earthquakes and landslides, dammed lakes are formed that can block river valleys. Lakes also appear in river valleys. These are the so-called old man lakes. How old lakes are formed can be judged by the long-term functionality of the river. If the climate is dry, you get lake lakes that stretch for hundreds of kilometers in chains. But when the channels wander, delta lakes are formed.
Lake Baikal
Baikal is the deepest lake on the planet. Its greatest depth is 1642 m, and its height above sea level reaches 460 m.
The formation of Lake Baikal occurred as a result of large faults in the earth's crust. Baikal is territorially located in Russia, on the border of the Buryat Republic and the Irkutsk region. The surface of the reservoir is 31722 km. More than three hundred rivers and streams flow into Baikal, including the Selenga, Turk, Snezhnaya, and Surma. And the Ankara River flows from it. Thus, Baikal is a flowing lake.
Baikal waters are fresh and transparent. The stones are visible even at a depth of 40 meters! The amount of minerals in the lake is insignificant, therefore water can be used as distilled.
The climate of Baikal is cool. Winter is mild and summer is cold. More than 2600 different representatives of plants and animals inhabit the lake, most of which is characteristic only for Lake Baikal.
Scientists determine the age of the lake at 25-35 million years. The origin of the name is not exactly established. But in translation from Turkic - Baikal (Bai-Kul) is a rich lake, which is an indisputable fact.
The origin of the swamps
Swamp is a part of land characterized by high humidity and acidity. In such places, standing or underground groundwater comes to the surface, but does not “linger” for a long time. All swamps occur in two ways:
- Waterlogging of the soil.
- Lake overgrowth.
According to the type of vegetation, marshes are divided into forest, shrub, grassy and mossy. The relief of bogs can be flat, convex, or bumpy. The formation of peat is characteristic of some marshes (dead, but not completely decomposed plants). Peat is used as a combustible material, as well as in medicine (mud therapy) and industry.
If we talk about how lakes and swamps are formed, then the latter is a process of evolution of the former. The sedimentation of silt gradually leads to pollution and shallowing of the lake, resulting in lowland marshes with rich water nutrition.
The value of swamps
Swamps are a valuable natural asset. This is a natural complex that is a habitat for rare species of flora and fauna.
Most of all swamps are spread in the tundra, taiga and forest-tundra - in areas with excessive moisture, where the amount of precipitation exceeds evaporation.
All swamps are divided into lowland, high and transitional. Lowlands feed on groundwater, high - atmospheric precipitation. Transitional swamps - the middle stage between the two previous types.
The plant world of swamps is very valuable to humanity. Lingonberries, cranberries, cloudberries, juniper - berries that are widely used in medicine. Many plants from swamps are used in perfumes and industry.
Marshes are an important source of food for rivers. Most reservoirs originate precisely from the swamps. Marshes are the second "light" planet after the forest. They process carbon dioxide and produce oxygen.
Secrets of the Lakes
On Earth, you can count more than a hundred lakes, the secrets of which are legends to this day.
For example, the lake of Death, which is located in Italy, only one name inspires fear. There is no vegetation around it, and in its waters there is no living creature. Swimming in the lake is forbidden, and hardly anyone wants to, because in it there is a high concentration of sulfuric acid.
Anomalous is Lake Pustoye in Alatau. Its water is clean and potable, but no living creature survives in this lake. It is completely empty.
The Kazakh lake with the name Dead is also alarming. People are constantly drowning in it. In this case, the bodies do not float, but seem to hang on the bottom of the lake in a vertical position upside down.
Many legends go not only about lakes, but also about their inhabitants. Everyone knows Lake Loch Ness, in which, according to eyewitnesses, a monster resembles a dragon. More than once a strange big fish with a long neck and a small head was noticed. The latest information is dated 2007. True or true - not finally proven.
The way lakes are formed is not a secret for anyone, but those strange phenomena that fill their depths are still a mystery even to scientists ...
A few words about the lakes of Russia
There are more than two million lakes in Russia, each of which keeps a secret. Since ancient times, water has fascinated people with its properties, both healing and killing. Therefore, it is not at all surprising that most of the legends are connected specifically with lakes.
At the same time, Lake Svetloyar charms and frightens with its mysticism. Its water can be stored for several years, while it does not lose its properties. The surroundings of the lake are extremely clean. Strange mirages often appear above the water, sometimes UFOs. From the bottom of the reservoir often come strange sounds, similar to the ringing of a bell. They say that at the bottom of Lake Svetloyarsk, the old city of Kitezh is buried, which went under water during the advance of the hordes of Khan Batu.
There are several lakes in Russia, in which, according to rumors, there is a likeness of the Loch Ness monster. Strange stories go about the dragon-lizard, living in Lake Brosno. Air bubbles were noticed on the surface of the water, which the locals mistook for a breathing monster under water. However, there is a logical explanation for this - rotting substances on the bottom of the lake that go to the surface. Secrets also covered Lake Ivachevskoe, Verdlozero, Lake Shaitan, Chany.
The only logical explanation for all the anomalies occurring in water bodies is how lakes are formed. Perhaps the reason for everything is the plant and animal world, not fully understood by mankind.
Conclusion
Lakes are an important constituent part of the Earth. Half of all plants and animals useful to humans are inhabitants of rivers and lakes. Why lakes are formed can be judged by the internal and external processes of our Earth. Tectonic and geological changes are the main reason for the formation of all reservoirs.