Application of Electrical and Seismic Geophysical Methods for Shallow Karstic Zones Detection at Limestone Rocks

Karst environments are characterized by weak zones and cavities at various depths and sizes, therefore they can be quite dangerous to building foundation. A high resolution geophysical survey was conducted in Kozani, in the area where the University of Western Macedonia is to be built in order to detect such features and prevent possible disasters. The study mainly focuses on the seismic survey and its capability to clarify the disputable results of previous GPR and ERT surveys at the area. Two different approaches in travel times study were applied. Seismic Refraction Tomography (SRT) and Multichannel Analysis of Surface Waves (MASW) methods provided vp and vs distribution, respectively, in 2D models across L1 profile. A different geophone-shotpoint array was used across L2 profile aiming at the delimitation of possible weak zones west and east of the L2 profile. The seismic survey was considered effective in detection of shallow karst features as well as to their discrimination from a massive body of similar response to electrical resistivity.