High impurity loading leads to reduced grain growth rates in the WAIS Divide 06A ice core, West Antarctica, as shown by regression analysis of new data from this core. Grain sizes measured on thin sections cut from the core were compared to concentrations of soluble and insoluble impurities measured on the remaining core over the same depth intervals. Comparisons were also made with the electrical conductivity of the ice (ECM). In general, samples with higher concentrations of several impurities, especially calcium, but also magnesium, sodium, and sulfate, showed smaller grain sizes. Physical understanding indicates that higher impurity loading reduces the grain growth rates. While some impurities increase electrical conductivity, others decrease it, which resulted in a noisy dependence of ECM on impurity loading observed in this work.
