| 释义 |
permafrost|ˈpɜːməfrɒst|
[f. permanent a. (n.) + frost n.]
Subsoil or other underground material that is at a temperature of less than 0°C throughout the year, as in Arctic regions; permanently frozen ground.
1943S. W. Muller Permafrost or Permanently Frozen Ground 3 The expression ‘permanently frozen ground’..is too long and cumbersome and for this reason a shorter term ‘permafrost’ is proposed as an alternative. 1952Sci. News Let. 2 Aug. 70/3 Currently it is studying permafrost, permanently frozen ground that creates many problems in construction work. 1955Peterson & Fisher Wild Amer. (1956) xxxiii. 357 Here on the tundra the permafrost forbids any digging and the Eskimos bury their dead above the ground. 1958New Biol. XXVI. 90 In the sub-arctic the peat has a permafrost layer, that is a layer, usually a foot or two below the surface, which remains frozen for the whole year round, and acts as an impermeable layer. 1968R. W. Fairbridge Encycl. Geomorphol. 838/1 Many other engineering problems result from changes in the mechanical properties of permafrost caused by thawing or freezing of its moisture beneath such structures as roadways or heated buildings. 1971New Scientist 8 Apr. 70/1 The heated pipeline would be laid for several hundred miles over or through a peaty soil where the permafrost may reach as much as 500 metres depth. 1974T. P. Whitney tr. Solzhenitsyn's Gulag Archipel. I. i. ii. 24 This wave poured forth, sank down into the permafrost, and even our most active minds recall hardly a thing about it. 1975Nature 1 May 27/1 A possible reason is that the increasing permafrost in the soil forced the late Vikings to change their burial customs. 1977New Yorker 9 May 95/2 There is ice under the tundra, mixed with soil as permafrost, in some places two thousand feet deep. |