The thermal environment of blocky materials in the mountains of central Asia

Geothermal investigations in the Transili Alatau Range (Northern Tien Shan) during 1974-87 reveal a significant difference between the thermal regime of coarse blocky materials and adjacent fine-grained soils. Mean annual temperatures inside the coarse debris are 2.5-4.0degreesC cooler than mean annual air temperatures (MAATs). In such conditions, permafrost may develop within coarse debris even under a positive mean annual air temperature. In the Transili Alatau Range, the process of perennially freezing is possible at altitudes of 1800-1900 m ASL where the MAA T is about 4degreesC. Copyright (C) 2004 John Wiley Sons, Ltd.