Project outline: To determine the conductivity profiles of the Earth over the South African region from the surface impedances derived by means of the 10 magnetotelluric (MT) stations in South Africa. To interpolate the surface impedances derived from the conductivity profiles to locations where there are no MT stations in order to estimate the E-field at these locations from measured geomagnetic data. The E-field is required to estimate the geomagnetically induced currents in power lines. To check the results against the surface impedances obtained along the transects investigated during the SAMTEX campaign.