

tabular berg

a flat-topped iceberg that shows horizontal banding; typically form by breaking from an ice shelf.


the open northern part of the boreal forest; consists of open woodland of coniferous trees growing in a rich floor of lichen (mainly reindeer moss or caribou moss), and is generally cold and swampy; lies immediately south of the tundra; in spring, it is often flooded by water from northward flowing rivers, the lower reaches of which are still frozen.


a layer or body of unfrozen ground occurring in a permafrost area due to a local anomaly in thermal, hydrological, hydrogeological, or hydrochemical conditions.


a small mountain lake or pool.

telescoped ice




temperature profile


temperature-gradient metamorphism



Glacier at the head of Canon Fiord, Ellesmere Island, Canada

terrestrial radiation

longwave radiation emitted by the earth, including its atmosphere.

thaw basin

a depression of the permafrost table created by naturally induced thawing.

thaw bulb


thaw consolidation


thaw consolidation ratio


thaw hole


thaw penetration


thaw settlement

compression of the ground due to thaw consolidation.

thaw sink

a closed thaw basin with subterranean drainage.

thaw slumping


thaw strain

the amount that frozen ground compresses upon thawing.

thaw unconformity


thaw weakening


thaw-sensitive permafrost


thaw-stable permafrost


thawed ground

previously frozen ground in which all ice has melted.

thawing (of frozen ground)


thawing front

the advancing boundary between thawed ground and frozen ground.

thawing index




thermal conductivity


thermal diffusivity

the ratio of the thermal conductivity to the volumetric heat capacity.

thermal erosion


thermal expansion (or contraction) coefficient


thermal pile


thermal properties of frozen ground


thermal regime of the ground
