Underground DC-geoelectrical and Seismic Surveys to Investigate Weakness Zones in Salt Rock Formations

The results of a research project concerning the safety assessment of underground waste disposal sites using non-destructive subsurface geophysical surveys within salt rock are presented here. The geophysical techniques were methodically adapted to detect possible weakness areas, like fault zones, disturbed rock zones and fractures with brines. The recent results concern DC-geoelectrical and seismic investigations within disused potash mines in Central Germany where brine reservoirs were supposed in the fractured anhydrite layers. The geoelectrical investigations served to determine areas with higher water content, the seismic surveys were useful to image layer boundaries of the geological units. The combined interpretation of the methods leads to more reliable information on the occurrence of potential weakness areas within the salt rock.