GEOPHYSICAL MONOGRAPH SERIES, VOL. 7, PP. 178-184, 1962
The thermal diffusivity and thermal conductivity of glacial ice at Wilkes Station, Antarctica
Air Force Cambridge Research Laboratories, Bedford, Mass., and the Institute of Polar Studies, Ohio State University, Columbus, Ohio
Institute of Polar Studies, Ohio State University, Columbus, Ohio
Near Wilkes Station, located in the Windmill Islands, East Antarctica, the westerly-flowing continental ice sheet terminates
in a north-south aligned edge. North and south of the Windmill Islands the ice sheet reaches the sea, but for a distance of
40 km, where the ice abuts the islands, it terminates as a nearly stagnant ramp 5 km from the coast.
During a period of 26 months the temperature of the upper 16 m of this ice was recorded at a site 8 km east-southeast of Wilkes Station, at an elevation of 262 m. Thermohms were emplaced at depths of 0, 0.5, 2, 4, 7, 11, and 16 m. At this site accumulation and ablation were balanced during the investigation, thus the surface was considered stable and the depth to the thermohms absolute. The density of the ice from 0–16 m was almost constant at 0.87±0.02 gm cm−3.
Analysis of the temperature measurements shows that the velocity of penetration of the annual sinusoidal temperature wave is independent of depth and that the amplitude of the wave decreases exponentially with depth. Thermal diffusivity and thermal conductivity were calculated from both the velocity of the wave and the decrease of the amplitude with depth and similar values were obtained. The mean values for this ice, of density 0.87 gm cm−3, when the average temperature during the two years was −10.7°C at the surface and −7.7°C at 16 m, are as follows:
Thermal diffusivity, α = 15.38 ± 0.9 × 10−3 cm−3 sec−1
Thermal conductivity, κ = 6.56 ± 0.4 × 10−3 cal sec−1 cm−1 °C−1
These values are considerably higher than those for pure ice, of density 0.917 gm cm−3, at 0°C:
Thermal diffusivity, α = 11.6 × 10−3 cm−2 sec−1
Thermal conductivity, κ = 5.3 × 10−3 cal sec−1 cm−1 °C−1
The higher values obtained at Wilkes Station can be explained in part by: (1) the thermal diffusivity and conductivity being higher at lower temperatures, (2) impurities within the ice, (3) convection in air bubbles and (4) the effect of thermal radiation within the ice and the absorption of solar radiation.
Citation: Cameron, R. L., and