Non‐destructive electrical resistivity tomography for indoor investigation: the case of Kapnikarea Church in Athens

Abstract The area inside and around the church of Kapnikarea in Athens (Greece), was explored by means of electrical resistivity tomography (ERT). ‘Flat base’ electrodes were used exclusively because the survey had to be fully non‐destructive. The performance of ‘flat base’ electrodes was satisfactory, leading to inversions of small root mean square (RMS) errors and reliable subsurface images, which were checked against existing borehole logs. High‐resistivity anomalies were observed beneath the floor of the church. They are attributed to possible voids, remains of ancient wells, or other man‐made structures concealed under the floor of the church. The results show that ‘flat base’ electrodes provided the advantage of fully non‐destructive geoelectrical measurements. They also show that the use of the non‐destructive ERT method offers a serious alternative and a complementary method to ground‐penetrating radar surveys inside existing monuments. Copyright © 2007 John Wiley & Sons, Ltd.