It is possible to study water infinitely. This colourless substance takes a leading place in human life. Water can take various forms. To be in a gaseous, liquid and firm look. It has surprising abilities which are clear not to all.
Why water does not freeze under a thick ice layer? It turns out that it from above is in a firm state, and from below in liquid. How can it be?
Physical properties of water
Proceeding from physical properties of water, it is known that temperature of its maximum density is +4º C. To pass into a firm state, its temperature has to reach zero. In formed at this ice all live perishes.
Lower temperatures accelerate process of transition of water of liquid state to firm. The nature thought over everything to the smallest details. Thanks to property of water to keep +4º C temperature at the maximum density, the inhabitants of reservoirs survive in winter conditions. Is explained by it why water does not freeze under a thick ice layer.
Reasons not of freezing of water
Before the coldest season there is a vertical movement of layers. In the fall water temperature is still high and did not fall up to 4º C. In the course of its gradual decrease warm and more films of water rise to a surface, and cold fall to a bottom. Such movement lasts until all water does not reach +4º C temperature. At the same time the top layer will be colder also than easier lower.
Gradually its temperature will go down, and the water surface to freeze. At first on a reservoir the ice crust is formed. Gradually, with fall of temperature, thickness of a crust will increase. When on the surface of ice the snow drops out, it will serve as additional protection of a reservoir against full freezing. It has heat-insulating properties.
Whatever cold was the winter, at the bottom of a reservoir it will be obligatory water. Its temperature will not fall lower than +4 degrees. Thanks to it in lakes and other reservoirs the life remains. Have no water the maximum density under such circumstances, under the influence of negative temperatures it all would turn into ice. Then all inhabitants of reservoirs would die. Thus, the nature cares for preservation of life.
Now knowing the answer to the question "why water does not freeze under a thick ice layer?", you can tell it to acquaintances. Likely it will be most interesting to fishermen. Thanks to this feature they can catch fish in the winter.