What is permafrost?

The name “permafrost” is relative, because it is believed that there is no eternal in nature. Since nature is changeable, despite the fact that for many centuries the processes in it seem to be unchanged. It would be more correct to call this phenomenon permafrost. Such permafrost is characterized by the absence of thawing; it can reach a depth of more than 1000 meters. When the air temperature rises, only the upper layers thaw, the deeper layers are not affected. Permafrost is widespread throughout the globe, most of all in areas close to the geographic poles, but it is found even in Africa, however, only in high mountain areas.