Table 122 405 



THERMAL CONDUCTIVITY, SPECIFIC HEAT, AND DENSITY OF SOILS AND ROCKS 



Table 122 contains values of the thermal conductivity k, specific heat c, density p, and 

 thermal diffusivity {th'ermometric conductivity) a[= k/(cp)] for various rocks and soils, from 

 "Heat Conduction," by Ingersoll, Zobel, and Ingersoll, 1 1948, courtesy of McGraw-Hill Book Co. 



Thermal Specific Thermal 



Tempera- conductivity heat Density diffusivity 



Material ture * k c p a 



°C. cal. sec. -1 cm. -1 "C. - * cal. g.- 1 °C. _1 g. cm. - * cm.' sec. -1 



Soils : 



Calcareous earth, 43% water 0.0017 0.53 1.67 0.0019 



Quartz sand, medium fine, dry.. .. 0.00063 0.19 1.65 0.0020 



Quartz sand, 8.3% moisture 0.0014 0.24 1.75 0.0033 



Sandy clay, 15% moisture 0.0022 0.33 1.78 0.0037 



Soil, very dry 0.0004-0.0008 ... ... 0.002-.003 



Some wet soils 0.003 -O.008 ... ... 0.004-.010 



Wet mud 0.0020 0.60 1.50 0.0022 



Rocks and building materials : 



Brick masonry 20 0.0015 0.20 1.7 0.0044 



Concrete, av. stone 0.0022 0.20 2.3 0.0048 



Concrete, dams 0.0058 0.22 2.47 0.0107 



Granite 0.0065 0.19 2.7 0.0127 



Limestone 0.0048 0.22 2.7 0.0081 



Marble 0.0055 0.21 2.7 0.0097 



Sandstone 0.0062 0.21 2.6 0.0113 



Traprock . ._ ... ... ... 0.0075 



Rock material av. for earth ... ... ... 0.010 



* Where temperature is not specified, ordinary room temperature may generally be assumed. 



1 Ingersoll, L. R., Zobel, O. J., and Ingersoll, A. C, Heat conduction, p. 243, McGraw-Hill Book Co. Inc., 

 New York, 1948. 



Table 123 



LATENT HEAT OF MELTING OF SEA ICE* 



Let 5" be the salinity of the ice and t, the freezing point of a sea water with the salinity 

 S. If the temperature t lies in the neighborhood of °C. the heat of fusion of pure ice 

 between t and t, can be considered constant and equal to 80 gram calories. The amount 

 of heat required to melt the sea ice is then the sum of the heat required to melt all the 

 pure ice in one gram of sea ice (80[1 — S{\ — At)]) and the amount of heat required 

 to increase the temperature of the pure ice and brine from t to t, (approximately = 0.5 

 (/« — 0), where At is the weight of all the pure ice in 1 gram of sea ice with salinity 

 \%o and temperature t and is equal to 1 — l/St, where St is the salinity of the brine at 

 t. Thus 



U = S0 (1--JJ-) +0.5(f.-*;) 



where U = number of calories required to melt 1 gram sea ice of the temperature / and 

 the salinity 5". 



Salinity — % 

 Tempera- 

 ture 2 4 6 8 10 15 



1 Malmgren, F., On the properties of sea ice, The Norwegian North Polar Expedition with the 

 Maud, 1918-1925, Scientific results, vol. 1, No. 5, 1927. 



SMITHSONIAN METEOROLOGICAL TABLES 



