Magnetotelluric and magnetovariational studies in southern Scotland1–4 have been followed by deep electrical soundings at an additional 30 sites. These lie on an approximately linear traverse extending from Kinlochbervie in the Lewisian Foreland to Borthwickbrae in the Scottish Borders (Fig. la). This traverse crosses the main geological zones of Scotland and follows reasonably closely the line of the LISPB5 seismic project (Fig. 1b). Full details of these geo-electric studies will be published elsewhere. We present here results of two-dimensional modelling of both the magnetotelluric and geomagnetic response functions6,7 obtained along the traverse.