Calculated apparent resistivities (upper) and phases (lower) at stations JJW360 (a), JJN561 (b) for both topography and 1-D model. The 1-D model is 90 m in top layer thickness, having the same depth profile as that of the sea model. Crosses and open circles indicate Zxy- and Zyx-mode responses, respectively. Calculated sounding data for the 3-D Jeju model are depicted in light grey symbols for comparison.