Cryogenic sampling of frazil ice deposits

Abstract : Studies of cold regions rivers have indicated the importance of frazil ice deposits in determining their winter regime. Frazil ice commonly deposits as hanging dams, anchor ice or longitudinal bars. A frazil ice deposit may contain variable distributions of ice particle size, density or porosity, and sediment concentration. A prototype cryogenic sampler has been used to examine frazil ice deposits beneath the ice-covered Tanana River near Fairbanks, Alaska. Modification of a streambed sediment sampler has provided full depth, in situ samples of frazil ice deposits, which are suitable for determining structure and overall composition.