Publication Date:
1976-01-01
Description:
Total impurity content of salt plus carbon dioxide was estimated as a function of grain size and depth in polycrystalline ice samples cored from a temperate glacier by measuring the electrical conductivity of the melt with air excluded. Conductivity decreased with increasing depth and grain size and ranged from × 10-5to 0.4 × 10-5Ω-1m-1at 0°C. The conductivity of pure water at 0°C is 0.1 × 10-5Ω-1m-1Studies of the configuration of the three phases and ofin situtemperature were also made. Thermodynamic constraints indicate that these impurities are probably concentrated as follows: about 5 mol m-3in the liquid in the veins along three-grain intersections, roughly 1 × 10-6mol m-2associated with grain-boundary area exclusive of veins, and about 0.7 × 10-3mol m-3in volume exclusive of veins and grain boundaries. The last of these categories seems to account for most of the impurities in coarse ice (grain size about 20 mm), but all three categories seem significant in fine ice (grain size about 2 mm). Differences in bulk impurity content possibly indicate different histories of flushing by water.
Print ISSN:
0022-1430
Electronic ISSN:
1727-5652
Topics:
Geography
,
Geosciences
