Several surface and borehole geophysical imaging methods and mapping techniques were employed at the investigation site to delineate the location and extent of old works. These included: 1) surface high resolution seismic (HRS) using compressional P-wave (HRPW) and shear S-wave (HRSW) reflection methods collected with three-dimensional (3-D) techniques; 2) cross-hole seismic tomography (XHT); 3) guided waves; 4) reverse vertical seismic profiling (RVSP); and 5) borehole sonar mapping. In addition, several exploration borings were drilled to confirm the presence of the imaged mine voids.

Read the Geophysical Technologies to Image Old Mining Works  paper.