Within the Junior Research Group Subrosion, the subproject electromagnetics deals with investigating and characterizing sinkholes, subsidence and subrosion structures by means of geoelectric/electromagnetic prospection. In particular, Ground-Penetrating Radar and Electrical Resistivity Tomography are applied on some test fields.
Dissolution of rocks such as anhydrite, gypsum, limestone, dolomite or salt rock enlarges fractures or pore space and finally results in voids and cavities within karst rocks. As voids and cavities are often fluid- or air-filled (or both) and the electrical properties of the fluid and air are in many cases significantly different to those of the surrounding karst rocks, electric and electromagnetic methods such as e.g. electrical resistivity tomography (ERT), ground-penetrating radar (GPR) and nuclear magnetic resonance (NMR) are potentially useful geophysical tools for the investigation of karst systems and sinkhole structures.
The aim is to utilise electromagnetic methods (GPR and ERT) for the characterisation of karst structures, sinkholes and disaggregation zones and distinguish those from the undisturbed rocks. Beside the surface application of those methods also borehole measurements are used (e.g. borehole GPR reflection and tomography measurements).