Frozen Ground

natural mineral and organic-mineral aggregates containing ice. They form in those parts of the upper-most layer of the earth’s crust which are frozen for a short time (seasonally) or permanently. A distinction is made between ground frozen for a short time and seasonally (less than one year), pereletoks (frozen for one to two years), and permanently frozen ground (frozen for more than two years). A further distinction is made between frozen ground containing ice and ground cooled to below 0°C that does not contain ice (called moroznye rocks).