Previously utilized escape tunnel in a known location. Dipole-dipole ERT survey was performed manually with an ABEM SAS 300B meter and 100 electrodes made from 1m and an n of 6. The tunnel location is not visible in the resistivity section using a full-color scale, only visible after adjusting the color scale. The tunnel was below the caliche layer and the tunnel lining was solidified with human urine.
