The Use of Electrical Resistivity Tomography for an Archaeological Investigation in the Old Oslo Harbor, Norway

An Electrical Resistivity Tomography (ERT) survey was conducted in downtown Oslo in conjunction with on-going archaeological investigations: boring, excavations and pollen analysis are presently being carried on at the site of the former medieval harbor. Seven ERT profiles were acquired to investigate subsurface conditions before the construction of a new road. The goal of this near surface geophysical survey is to detect possible archaeological artifacts in the marine clay layer down to 10 m depth without disturbing the construction site. Based on 3D visualization and integration with archaeological investigations, some resistive bodies localized by the ERT are identified as buried timbers or riverbed sediments. Other anomalies are of unknown origin, sampling is proposed in order to solve the ambiguity between recent structures and buried ships.