Sea salt dependent electrical conduction in polar ice

A simple method is described for detecting annual stratification of ice cores, and layers of high acidity due to violent volcanic eruptions in the past. The method is based on a relationship between the H3O+concentration (pH) of melted samples and the electrical current between two brass electrodes moved along the cleaned ice-core surface. The “conductivity” is explained in terms of the initial current in the build-up of space charges. Acidity and current profiles are shown through layers deposited soon after historically well-known volcanic eruptions, such as Katmai, a.d. 1912, Tambora, a.d. 1815, Laki, a.d. 1783, Hekla, a.d. 1104, and Thera (Santorin)c. 1400 b.c. High-acidity layers seem to be the cause for the internal radio-echo layers in polar ice sheets.