J. Phys. Chem. 1983, 87, 4157-4160
4157
Measurement of Direct Current Conductivity on Ice Samples for Climatological Applications J. Schwander,' A. Neflel, H. Oeschger, and B. Stauffer Physics Institute, University of Bern, Bern, Switzerland (Received: August 23, 1982; I n Final Form: Februaty 2, 1983)
The electrical conductivity of natural ice samples is strongly correlated with the acidity of the melted sample and can therefore be used for climatological studies. Two physical aspects concerning this conductivity measurement have been investigated. For the used setup with unguarded electrodes it could be shown that volume conduction dominates surface conduction at -15 "C. A relation between the measured conductance and the specific conductivity is established. The aging observed on stored ice samples is shown to be strongly dependent on the composition of the gas in which the ice samples are stored. Ammonia diffuses rapidly into the ice and changes its conductivity.
Introduction An electrical conductivity stratigraphy using a pair of brass electrodes that are moved over a cleaned plane surface of an ice core has been proposed and successfully applied by Hammer.' He applies a voltage of 1250 V dc to the electrodes. The distance between the electrodes is 10 mm. He showed that for cold natural ice the measured current is a function of the pH value of the melted sample (only for pH
