SOILS
2021-08-27 13:51:01.0 [tstevens] update Definition (A layer of soil or bedrock at a variable depth beneath the surface of the earth in which the temperature has been below freezing continuously from a few to several thousands of years.); update Definition (American Meteorological Society Glossary of Meteorology);
PERMAFROST
A layer of soil or bedrock at a variable depth beneath the surface of the earth in which the temperature has been below freezing continuously from a few to several thousands of years.