How nice after a hard week to spend a weekend somewhere outside the city by the lake, away from the bustle of the city. For many, this pastime is an integral part of the holiday. But do people really know how lakes are formed, how they can be useful, and how sometimes they can harm?
What are lakes?
A lake is a closed depression in the ground, where underground and surface waters flow down and do not evaporate. Such a depression is called a lake basin. By origin, all lakes are divided into tectonic, river (oxbow lakes), seaside, failed, underground.
By salinity, fresh (Baikal), brackish (Chany) and s alt lakes (Chad) are distinguished. All reservoirs can be wastewater when one or more rivers flow out of the lake; flowing - several rivers flow into the lake and one or more flows out; drainless - rivers only flow into the lake.
Filling of reservoirs occurs due to precipitation (rain, snow) or with the help of groundwater. Also, the food of the lake can be mixed.
According to the mineral composition of the lakethere are carbonate, sulfate and chloride.
How are lakes formed?
Most of the lakes of our planet are of tectonic origin, that is, they were 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 the level of the oceans. Its shores are covered with hard rocks, which are weakly susceptible to erosion. All the deepest lakes are formed as a result of faults in the earth's crust.
A lot of reservoirs are also obtained as a result of geological processes (weathering, erosion, glacier activity). Among them, the most common are glacial lakes on the plains and in the mountains, as well as sinkholes, which were formed as a result of thawing of earth rocks. These 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 oxbow lakes. How oxbow lakes are formed can be judged by the long-term functionality of the river. If the climate is dry, pool lakes are obtained, which in the form of chains stretch for hundreds of kilometers. But when the channels wander, deltaic lakes are formed.
Lake Baikal
Baikal is the deepest lake on the planet. Its greatest depth is 1642 m, and the 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 located in Russiaborder of the Buryat Republic and the Irkutsk region. The area of the reservoir is 31722 km2. More than three hundred rivers and streams flow into Baikal, including the Selenga, Turka, Snezhnaya, and Surma. And the Ankara River flows out of it. Thus, Baikal is a flowing lake.
Baikal waters are fresh and transparent. Stones are visible even at a depth of 40 meters! The amount of minerals in the lake is negligible, so the water can be used as distilled water.
The climate of Lake Baikal is cool. Winters are mild and summers are cold. More than 2,600 different representatives of plants and animals live in the lake, most of which are typical 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 translated from Turkic - Baikal (Bai-Kul) is a rich lake, which is an indisputable fact.
Origin of swamps
Swamp - part of the land, characterized by high humidity and acidity. In such places, stagnant or underground groundwater comes to the surface, but "does not linger" for a long time. All swamps occur in two ways:
- Soil waterlogging.
- Overgrowing lake.
According to the type of vegetation, swamps are divided into forest, shrub, herbaceous and moss. The relief of the bogs can be flat, convex or bumpy. Some swamps are characterized by the formation of peat (dead, but not completely decomposed plants). Peat is used as a combustible material, as well as in medicine (mud treatment) and industry.
If we talk abouthow lakes and swamps are formed, the latter is the process of evolution of the former. The deposition of silt gradually leads to pollution and shallowing of the lake, resulting in low-lying swamps with rich water supply.
The value of swamps
Marshes are a valuable natural asset. This is a natural complex, which is a habitat for rare species of flora and fauna.
Most of all swamps are common in the tundra, taiga and forest-tundra - in areas with excessive moisture, where precipitation exceeds evaporation.
All swamps are divided into lowland, upland and transitional. The lowland ones feed on groundwater, the upland ones feed on atmospheric precipitation. Transitional swamps are the middle stage between the two previous types.
The flora of swamps is very valuable for humanity. Lingonberries, cranberries, cloudberries, junipers are berries that are widely used in medicine. Many plants from swamps are used in perfumery and industry.
Marshes are an important source of river nutrition. Most of the water bodies originate from the swamps. Swamps are the second "lungs" of the 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 legendary to this day.
For example, the lake of Death, which is located in Italy, by its name alone inspires fear. There is no vegetation around it, and living creatures in its waters. It is forbidden to swim in the lake, and hardly anyone wants to, because it contains a high concentration of sulfuric acid.acids.
The Empty Lake in Alatau is considered abnormal. Its water is clean and drinkable, but no living creatures take root in this lake. It's completely empty.
Also alarming is the Kazakhstani lake with the name Dead. People are constantly drowning in it. At the same time, 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 Loch Ness, in which, according to eyewitnesses, a monster resembling a dragon lives. More than once a strange large fish with a long neck and a small head has been seen. The latest information is dated 2007. True or false - not definitively proven.
How lakes are formed is no longer a secret to anyone, but the strange phenomena that fill their depths are still a mystery even to scientists…
A few words about Russian lakes
There are more than two million lakes in Russia, each of which holds a secret. Since ancient times, water has fascinated people with its properties, both healing and deadly. Therefore, it is not at all surprising that most of all legends are associated with lakes.
At the same time, Lake Svetloyar fascinates 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. Strange sounds are often heard from the bottom of the reservoir, similar to the ringing of a bell. They say that the old city of Kitezh is buried at the bottom of Lake Svetloyarskoye,who went under water during the offensive of the hordes of Batu Khan.
There are several lakes in Russia where, according to rumors, the likeness of the Loch Ness monster lives. Strange stories go about a lizard dragon living in Lake Brosno. Air bubbles were seen on the surface of the water, which the locals mistake for a breathing monster underwater. However, there is a logical explanation for this - the decay of substances at the bottom of the lake that come to the surface. Lake Ivachevskoe, Verdlozero, Lake Shaitan, Chany are also covered with secrets.
The only logical explanation for all the anomalies that occur in bodies of water is how lakes form. Perhaps the reason for everything is the flora and fauna, not fully studied by mankind.
Conclusion
Lakes are an important 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.
