Accumulation of Anthropogenic Radionuclides in Cryoconites on Alpine Glaciers

Cryoconites are airborne sediments which accumulate on the surface of glaciers. In samples of cryoconites a temperate Austrian glacier high activity concentrations of anthropogenic radionuclides were found, which stem from global and Chernobyl fallouts. Radionuclides identified were 137Cs, 134Cs, 238Pu, 239þ240Pu, 90Sr, 241Am, 60Co, 154Eu, 207Bi, and 125Sb. Given the approximately known isotopic ratios, Cs and Pu can be separated into the contributions of either source of origin. Published 137Cs/134Cs and 239þ240Pu/238Pu ratios were used for the discrimination of the Dachstein-glacier cryoconites according to their origin from global or Chernobyl fallout. Two different groups of cryoconites were identified, an older population dominated by nuclear weapons fallout and a younger one with predominant Chernobyl fallout. With those data a simple model was formulated to demonstrate the transition and mixing of these 2 populations on the glacier surface.JRC.DDG.H.4-Transport and air qualit