Geophysical Mapping: Problem Details 3 of 39 Problem Name: Cavity detection Problem Type: Civil Engineering Assigned Methods: + BEAM G4 SCAN Electrical Methods + Borehole imaging, Structure logging Borehole Methods + Geoelectrics - Crosshole tomography Electrical Methods + Geoelectrics - Tomography (surface based) Electrical Methods + Ground infrared thermography Thermic Methods + Ground penetrating radar (surface-based) Electromagnetic Methods + Ground penetrating radar - Borehole tomography Electromagnetic Methods + Micro gravity Gravity + Seismic crosshole tomography Seismic Techniques + Shallow reflection seismics Seismic Techniques + Tunnel Seismic Prediction (TSP) Seismic Techniques + Tunnel infrared thermography Thermic Methods + Vertical seismic profiling (VSP) Seismic Techniques + Very-high resolution reflection seismics Seismic Techniques 0 Airborne magnetics Magnetic Methods 0 DC geoelectrics - Profiling Electrical Methods 0 Frequency-domain electromagnetics - Profiling Electromagnetic Methods 0 Frequency-domain electromagnetics - Sounding Electromagnetic Methods 0 Ground magnetics Magnetic Methods 0 Refraction seismic tomography (surface-based) Seismic Techniques 0 Seismic surface waves methods Seismic Techniques 0 Self potential Electrical Methods 0 VLF / VLF-R, Radiomagnetotellurics Electromagnetic Methods    '+' = Technique applicable; '0' = Application possible/limited use