Natural radioactive isotopes in glacier meltwater studies

抄録

Glaciers are decaying due to global warming. Svalbard is a very sensitive area within the European High Arctic and studies on glacier changes and evolutions are representative for the Arctic. The present work aims glaciers at Spitsbergen; we investigated meltwater supplied by glacierized basins in introducing radioactive isotope measurements in combination with classical parameters. Among the natural radioactive elements, the most promising is the noble gas radon, more precisely the isotope ²²²Rn, with a short half life of 3.8 days and the possibility of automated continuous measurements. Measurements of radon in glacier meltwater showed surprisingly high concentrations thus enabling investigations with radon as valuable tracer. Only meltwater in contact with rock or sediments has the possibility to be charged with radon. Varying radon concentrations can be linked to changes in mixing meltwater from different origins, roughly the surface of glaciers (supraglacial), within (englacial) and under ice (subglacial). We are able to collect information on the glacier drainage system and its evolution over time and thus contribute to the study of glacier dynamics. Results from three sampling periods on Werenskioldbreen glacier, covering different glaciological seasons, are presented and discussed in this study. The potential results of further continuous measurements will give supplementary information on drainage footpaths and the style and system of the draining of glaciers. Our study intends also a better understanding of the response of glaciers to environmental parameters and, on a longer term, to make a contribution to climate change studies.