ELECTRICAL RESPONSE OF THE SUMMIT-GREENLAND ICE CORE TO AMMONIUM, SULFURIC-ACID, AND HYDROCHLORIC-ACID

Electrical and chemical analysis of the GRIP ice core from Summit in c entral Greenland confirms that the ECM current is controlled solely by acids in the ice, though there could be different responses for diffe rent acids. The dielectric conductivity is dependent on strong acid, o n sea salt chloride, and also on ammonium concentrations in the ice. T he response to NH4+ is similar to that of sea salt chloride, as they b oth conduct only at AC frequencies, but NH4+ is approximately twice as conductive per mole. The response to the strong acids shows results c onsistent with earlier work, with similar responses throughout the len gth of the core. It seems as if all the thousands of electrical peaks in the GRIP core may be explained by the response to just three chemic al species: acidity, ammonium salts, and a third component which is pr obably chloride.