270 black. PERMAFROST [Ch. 14 



mented with Arctic research stations such as are found in the Soviet 

 Union where more than 30 natural-science laboratories with permanent 

 facilities and year-around basic studies in all phases of Arctic science 

 are going on. The Arctic Research Laboratory at Barrow (Shelesnyak, 

 1948) is a start in the right direction. The academic approach must 

 accompany the practical approach if satisfactory solution of the prob- 

 lem is to be found. 



To name all the specific topics for future research would make this 

 section unduly long, as no phase of permafrost is well-known. However, 

 the author reiterates that the problems cannot be solved adequately 

 until the phenomena of heat flow in all natural and artificial materials 

 in the earth is understood and correlated with insolation, atmospheric 

 conditions, geothermal gradients, and the complex surface of the earth. 

 Then, possibly, criteria can be set up to evaluate within practical 

 limits the effect of various structures on the dissipating surface of 

 the earth. The complexities of geology (lithology, structure, and 

 texture of soils and rock), hydrology, vegetation, and climate of the 

 Arctic make the solution a formidable task but the research an in- 

 triguing problem for all earth scientists. 



REFERENCES 



Barnes, Lynn C. (1946). Permafrost, a challenge to engineers: Military Engr., 

 vol. 38, No. 243, pp. 9-11. 



Birch, Francis (1948). The effects of Pleistocene climatic variations upon geo- 

 thermal gradients: Amer. Jour. Sci., vol. 246, No. 12, pp. 729-760. 



Black, R. F., and Barksdale, W. L. (1949). Oriented lakes of northern Alaska: 

 Jour. Geol, vol. 57, No. 2, pp. 105-118. 



Bryan, Kirk (1946a). Cryopedology, the study of frozen ground and intensive 

 frost-action with suggestions on nomenclature: Amer. Jour. Sci., vol. 244, No. 

 9, pp. 622-642. 



(1946b). Permanently frozen ground: Military Engr., vol. 38, No. 246, 



p. 168. 



(1948). The study of permanently frozen ground and intensive frost- 



action: Military Engr., vol. 40, No. 273, pp. 304-308, discussion, pp. 305-308. 

 (1949). The geologic implications of cryopedology: Jour. Geol., vol. 57, 



No. 2, pp. 101-104. 

 , and Albritton, C. C, Jr. (1943). Soil phenomena as evidence of climatic 



changes: Amer. Jour. Sci., vol. 241, No. 8, pp. 469-490. 



* Cailleux, Andre (1948). Etudes de cryopedologie : Expedition arctique, sec- 

 tion des sciences naturelles, pp. 1-67. 



Cederstrom, D. J. (1948). Ground-water data for Fairbanks, Alaska: Manuscript 

 on open file, U. S. Geological Survey, Washington, D. C. 



* Articles which are comprehensive in scope or which contain extensive bibli- 

 ographies. 



