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 (137)Cs, (134)Cs, (238)Pu, (239+240)Pu, (90)Sr, (241)Am, (60)Co, (154)Eu, (207)Bi, and (125)Sb. Given the approximately known isotopic ratios, Cs and Pu can be separated into the contributions of either source of origin. Published (137)Cs/(134)Cs and (239+240)Pu/(238)Pu 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 two populations on the glacier surface.
Tieber
A
A
Division of Physics and Biophysics, University of Salzburg, Department of Materials Engineering and Physiks, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. alexandra.tieber@sbg.ac.at
Lettner
H
H
Bossew
P
P
Hubmer
A
A
Sattler
B
B
Hofmann
W
W
D001317:Austria; D002588:Cesium Radioisotopes / Q000032:analysis; D047852:Chernobyl Nuclear Accident; D004784:Environmental Monitoring; D046448:Ice Cover / Q000737:chemistry*; D011868:Radioisotopes / Q000032:analysis*
D002588:Cesium Radioisotopes; D011868:Radioisotopes