Overview on radon measurements in Arctic glacier waters

Abstract. We present a possibility to investigate the presence of the subglacial component in waters supplied by glacierized basins in introducing radioactive isotope measurements, in combination with more classical parameters like temperature and electrical conductivity. Among the natural radioactive elements the most promising is the noble gas radon isotope ²²²Rnv. With a half-life of 3.8 days, it constitutes a short time tracer and also allows continuous measurements. In waters drained out from a target landbased Svalbard glacier, radon levels show surprisingly high values up to 33 Bq L⁻¹ in the accumulation season. In the ablation period varying radon concentrations can be linked to mixing of waters from different origins, roughly supraglacial (meltwater and rain water), englacial and subglacial. Only water recently in close contact with bedrock or sediments can be charged with radon. Results from several years of radon measurements on Werenskiold glacier, in ablation and accumulation seasons, are presented and discussed. The results of continuous measurements give proxy information on drainage footpaths and the style and system of the draining of glaciers. They enable to distinguish the presence of a subglacial component in water flowing from the glacier system in different seasons of the year and thus are a step towards the indication of the prevailing type of glacier drainage during summer and winter seasons.