Permafrost

nature of ground properties formation and an estimation of these properties for the temperature
mode of Mars, Moon and some other planets.
Frozen grounds are multi-component and multi-phase systems. The main components are
rock skeleton, water, ice and pore gas. Theoretical aspects of solid physics, solution and surface
thermodynamics were applied for the theoretical analysis of thermophisical characteristics (heat
capacity and thermal conductivity) of main components of dispersed soils and water in it at
different temperature conditions. Experimental approbation was carried out with the use of
adiabatic and differential-scanning calorimeter. Results of theoretical knowledge and
experimental data comparison are presented.
Concluded, that temperature dependence of heat capacity of rock skeleton, ice and
unfrozen water (pore solutions) of experimental data is in the good correspondence with
theoretical one. It is need to take into account components temperature for a high accuracy of
calculated heat capacity of rocks. In an interval of temperatures from + 20 up to - 20 0 С the heat
capacity of a rock skeleton it is possible to consider constant (mistake + 10 %).
The thermal conductivity of a mineral skeleton insignificantly depends on temperature,
having the small tendency to its decrease at downturn up to -200 K, and at ice has extreme
character - essentially raising from 273 K till 70-80 K and then sharply falling. The thermal
conductivity of pore solution decreases with temperature pulldown. The thermal conductivity is
a dynamic characteristic as depends on speed and direction of process of freezing-thawing; the
structural transformations result in occurrence of a hysteresis at alternation of cycles of heating
of cooling.
The effects of heterogeneity of structure, in a potent degree are shown at low temperatures.
The distinction in factors of linear expansion of minerals composing a skeleton and crystals in
defective structure of ice, results in occurrence of pressure and formation of microcracks, both
in ice, and in a rock skeleton.
Key words: Thermal conductivity, heat capacity, hysteresis, multiphase and multiple systems,
negative temperatures
Cryoturbation in Permafrost Soils and NortherAgricultural-landscape
Ecology under Global Climatic Change
102
P.P. Gavriliev and R.N. Ivanova
(Melnikov Permafrost Institute SB RAS)
Abstract: The paper discusses the basic types of cryoturbation in permafrost-affected soils
within the North Taiga and Middle Taiga subzones of Yakutia.
Under contemporary rapid climate change, permafrost-affected soils, the active layer and
the upper part of an ice-rich substrate, especially that of frozen ground containing thick ice
wedges, are subject to exogenous processes. Anomalously extreme cryogenic and hydrothermal
processes are accompanied by cryoturbation in soils of the active layer.
Cryoturbations are diverse and include:
1) cryoturbated permafrost soils with polygonal-wedge structures that result in three levels of