The nature of our planet is unique. It is interesting that there is nothing stationary on Earth, everything changes. We are accustomed to the fact that the main changes in the surrounding nature depend on man. However, amazing metamorphoses are associated with karst lakes. This article will tell you what karst lakes are.
What is this?
Karst is a layer of earth consisting of soft rocks, which, due to their properties, people use in construction, i.e. limestone, gypsum, surfaces of sulfate origin, etc. Groundwater, having fluidity, such layers are washed away, and as a result, dips are formed, which are filled with water. Most of the time it's fresh. However, if the layers are composed of rock s alt, then s alt water can be obtained, saturated with minerals dissolved in it. This is how a karst lake is formed. It can occur both on the surface and underground, in caves, which also appear due to the formation of voids in the rock layer. Such caves are also called karst.
Peculiarities of origin
Karst lake is a pit,filled with underground water. It is formed as a result of the collapse of the earth layer, which consisted of soft calcareous rocks. The water in such reservoirs is transparent, because there is no sand at the bottom, but only light limestone, mineralized and purified from harmful biological impurities. Therefore, it can be called "alive". Such a reservoir does not warm up to the bathing temperature due to the large number of springs that bring groundwater to the surface. There are few living creatures in such lakes, but fish are found. How it gets there and what it eats is a mystery! Unlike ordinary lakes, the karst lake boasts water that is free of duckweed and reed vegetation even off the coast.
Wandering Lakes
A karst lake can be short-lived because groundwater can erode limestone layers and change direction or go deeper. Then they disappear, and only the legends associated with them remain. Wandering lakes are located in different parts of our country. In the Arkhangelsk region there is a reservoir Semgo, which went into the ground several times in a row. Once every few years, a high- altitude natural reservoir in Dagestan, Rakdal-Khol, appears and then disappears. In the Vytegorsky district in the Vologda region, Kushtozero disappeared within three days. Shimozero, located not far from Onega, surprises the inhabitants of the surrounding settlements not only by the fact that at the beginning of summer it is filled with water, but also by the fact that by autumn its contents go underground. This lake has a round basin, which resembles a funnel, because the water in it rotates. The locals called this place the Black Pit.
Thermokarst and technogenic karst lakes
The emergence of karst lakes is also associated with changes in the temperature regime in various areas. With an increase in the average annual air temperature, a layer of ice begins to thaw in permafrost areas, voids are formed, the surface of which falls through and is filled with melt water. This is how thermokarst lakes are formed. In addition to this type of reservoirs, there are also technogenic karst formations. Most often, they are formed in places where a person develops rocks that served him as a building material. The adits and quarries are abandoned, but the resulting voids have contributed to the emergence of new karst caves and lakes. So, apparently, this time it was not without human intervention.
Karst lakes of the Samara region
Examples of karst lakes can be found in various regions of our country, although these objects are still poorly understood. They are mainly studied by local divers. The pearl of the Samara land - the Zhiguli Mountains, consisting mainly of calcareous rocks - contains a large number of karst caves and lakes.
One of them is called Blue Lake. Located in the Sergievsky district of the Samara region near the village of Staroye Yakushkino. It has a round funnel and an intense blue color, for which it got its name, it is supplied with water from hydrogen sulfide sources. There is a belief that if a person swims in its middle,then it can be sucked in by giant bubbles rising from the bottom. The lake appeared, according to preliminary data, 250 years ago. And they call it dead because of the complete absence of life in it. The water body White Well is also interesting, which is located near the village of Shiryaevo in the upper reaches of the Shiryaevsky ravine. The name of the well may indicate the bottomless depth of the lake or the special freshness, transparency, good quality of water. This reservoir is a natural object of the Samarskaya Luka National Park. Another lake of the "Samarskaya Luka" was named for an event that the old-timers of the village of Askula remember. 30-40 years ago, the level of a karst lake in the upper reaches of the Askulsky ravine to the north-east of the village suddenly rose, water poured into the ravine. Hence the name "Flood".
Thus, a karst lake is a unique little-studied natural phenomenon that contains many mysteries and mysteries.
