A permanently frozen aggregate of ice and soil occurring in very cold regions.
Permafrost is ground that remains frozen all summer. Follow the link for more in depth information on Permafrost.
Perennially frozen layer of the soil that forms when the water there freezes. It is found in arctic tundra.
Layer of permanently frozen soil.
Ground below 32ºF (0ºC) all year round.
A layer in the ground that remains frozen throughout the year that generally occurs where the annual mean air temperature is below -1 C. Most permafrost lies below an active layer that thaws for periods of weeks to months in the summer. Permafrost is continuous over most land north of 65 N and discontinuous south to about 50 N in Canada and to about 47 N in eastern Asia. The total area covered is about 7.6 million km2 of continuous and 17.3 million km2 of discontinuous permafrost, with the total volume equivalent to a sea level change of 0.08-0.18 m.
Perenially frozen ground.
A layer of soil at varying depths below the surface in which the temperature has remained below freezing continuously from a few to several thousands of years.
Layer of permanently frozen water ice believed to lie just under the surface of Mars.
Permanently frozen regolith, ranging in thickness from 30 centimeters to over 1000 meters.
ground that is permanently frozen
A layer of ground which stays frozen year round.
Land that remains at or below zero degrees Celsius continuously for at least 2 consecutive years. Permafrost is not defined by soil moisture content, overlying snow cover, or location; but is defined solely by temperature. Permafrost may contain over 30 percent ice, or essentially no ice at all. It can be covered by several meters of snow, or be completely bare of snow. Underground, permafrost consists of frozen soils ranging from gravel to silt. Silty soil is composed of fine, powdery sedimentary particles. They possess great "wicking" capabilities that enable water to migrate and accumulate as large bodies of ice in the permanently frozen silt. Two main areas of permafrost are recognized. Permafrost areas which do not thaw at all during the year and permafrost areas whose upper layers thaw briefly during the warm season underlain by thicker layers which do not thaw even at mid-summer.
Ground that is frozen year-round.
perm-a-frost]- frozen soil found in the Arctic and subarctic regions whose age may go back thousands of years.
a soil layer below the surface of tundra regions that remains frozen permanently.
This term applies to ground that is continuously at a temperature below 32 degrees for more than two years. Very common in Alaska and Siberia.
a layer of soil which remains frozen from year-to-year; permafrost exists in many northern soils and may be a few inches to 1000 feet thick; continuous permafrost occurs everywhere in a given area, and discontinuous permafrost occurs in some places but not in others in a given area.
A layer of soil beneath the ground's surface that remains frozen throughout the year.
The soil condition under which the subsoil rarely, if ever, thaws in summer.
A layer of earth that is permanently frozen even though the overlaying layers may thaw.
perennially frozen ground that occurs wherever the temperature remains below 0°C for several years
Earth materials that remains continuously at or below 0oC for at least two consecutive years.
soil frost that doesn't melt in the summer
A permanently frozen layer of soil.
perennially frozen ground, often containing ice-wedge polygons, pingos, and other unusual features.
A permanently frozen layer at variable depth below the surface in frigid regions of a planet (as Earth).
A permanently frozen layer in the soil in frigid climates, found in alpine, arctic, and antarctic regions.
Perennially frozen ground in areas where the temperature remains at or below 0o C for two or more years in a row.
Subsoil which remains below freezing point throughout the year, as in polar regions.
permanently frozen ground.
The permanent freezing of the subsoil in tundra regions.
Zone of permanently frozen water found in high latitude soils and sediments. Five types of permafrost have been recognized: continuous permafrost, discontinuous permafrost, sporadic permafrost, alpine permafrost, and subsea permafrost.
The term used to describe an area of ground continuously frozen. Only for very brief periods during the summer will the surface thaw.
Permanently frozen subsoil.
Soil, rock and sediment where the temperature stays below 0°C for at least two consecutive winters and the summer in between. Permafrost usually occurs in a layer some distance beneath the topsoil.
layer of soil or rock, at some depth beneath the surface, in which the temperature has been continuously below 0°C for at least several years; it exists where summer heating fails to reach the base of the layer of frozen ground.