Environmental Radionuclides (R. Purtschert and T. Stocker)
Environmental tracers are powerful tools to study a multitude of processes in the geo- hydro and atmosphere. In particular radioactive isotopes provide unique information about pathways and timescales of the processes involved. One major requirement for “dating” is that the half-life of the isotope matches the time range of the processes under study. Since the concentrations of natural and man-made radioisotopes in natural reservoirs are generally extremely low, research in this field is based on the most sensitive analytical techniques such as (low level counting (LLC), accelerator mass spectrometry (AMS), atom trap trace analyses (ATTA)).
For many years, isotope techniques have been used in our research group. Special emphasis is placed on the application of radioactive noble gas isotopes because they are chemically inert and can therefore be regarded as ideal dating tracers. For 37Ar, 39Ar and 85Kr our underground LLC laboratory is unique in the world. The wide range of tracers measured at our institute and in collaborating laboratories offers unique possibilities to constrain age structure, origin and dynamics of ground- and pore waters. This provides the basis for the understanding of subsurface processes, the investigation of new dating methods and the application of environmental tracers in all kind of environments. Overall, processes on time scales between minutes and millions of years have been studied and in the recent past in our group.