Permafrost

Methods of Theoretical and Experimental Definition of Phase
Equilibrium Parameters for Saline Soils and Cryopegs
E.M. Kulish, Volkov N.G., Komarov I.A.
(Lomonosov Moscow State University, Faculty of Geology, Department of Geocryology)
Abstract: The problem of the determination of the thermodynamic characteristics for frozen
salted soils are called attention.
From many experimental methods using for getting the phase balance parameters the
cryoscopic method as one of most informative was chosen. The thermogramms handling was
permitted to find freezing points of soils.
Computation were carried out by means of the program «FREZCHEM2». The point
calculation reliability of the program was improved by applying the Gibbs energy minimization
approach to computing equilibrium in CRREL laboratory, used for calculation of phase
diagrams, of freezing point temperature and other parameters of phase equilibrium for solutions
with any composition and concentration, and especially for high concentrated solutions in
frozen soils – cryopegs. But it is applicable only for free solutions in volume.
There are submitted data of calculating and experimental results in this report. The
findings of modeling on «FREZCHEM2» were used for construction of phase graphs and
determination of freezing point temperatures. The experimental operation was made for kaolin
clay and quartz rock samples containing following ions of soluble salts: NaCl, KCl, CaCl2,
MgSO4 in different percentage. The results were compared to each other and the satisfactorily
convergence has been achieved.
Estimation of phase balance parameters for cryopegs is very hard according to their high
mineralization and chemical reactions. The program «FREZCHEM2» allowed to get
computational data and to create dot chart. It’s using enables to appreciate the freezing point
temperature for cryopeg and the temperature of cryopeg’s formation by finding the starting
point of the sulfate precipitation.
Key words: cryoscopic method, phase equilibrium parameters, cryopegs.
Influence of Petroleum Pollution on Seasonal
Thawing and Freezing Depth of Soils
Ershov E. D., Motenko R.G., Nefedieva Yu. A., Parmuzin S.Yu.
(Moscow State University, Faculty of Geology, Department of Geocryology)
Abstract: The oil recovery, its storage and transportation is inevitably accompanied by
hydrocarbon environmental contamination. Passages of petroleum annually make millions tons.
The environmental problem arising at it has global character. This problem completely concerns
to a zone of distribution of frozen and freezing grounds. According to "Hydrospecgeology", in
Western Siberia in places of an oil recovery thickness of petroleum layer exceeds some cm. The
temperature mode and depth of seasonal thawing (freezing) of soils depend on many factors,
including from their structure, humidity, thermal properties, albedo of surfaces, influences of a
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