Fig. 1. Schematic diagram for background model.背景模型示意图

Fig. 2. Schematic diagram for tetrahedral element and edge numbers.四面体单元及其棱边编号示意图

Fig. 3. One-dimensional layered medium model.一维层状介质模型

Fig. 4. Comparisons of modelling results of quadratic interpolation and analytical solutions based on total fields and secondary fields: (a) Apparent resistivity ; (b) phase . 基于总场和二次场的二次插值的模拟结果与解析解的对比T为周期)　(a) 视电阻率 ; (b) 相位

Fig. 5. COMMEMI-3D1 model. The dashed lines in (a) are the x and y survey lines. COMMEMI-3D1模型, 其中(a)图中虚线为x和y测线

Fig. 6. Comparisons of modelling results and Zhdanov et al^[24] of (a), (b) x survey line and and (c), (d) y survey line (profile is 0.1 Hz). (a), (b) x和(c), (d) y测线模拟结果和Zhdanov等^[24]的结果对比(剖面为0.1 Hz)

Fig. 7. Comparisons of modelling results and Zhdanov et al^[24] of (a), (b) x survey line and and (c), (d) y survey line (profile is 10 Hz). (a), (b) x和(c), (d) y测线模拟结果和Zhdanov等^[24]的结果对比(剖面为10 Hz)

Fig. 8. COMMEMI-3D2 model.COMMEMI-3D2模型

Fig. 9. Comparisons of modelling results and algorithm results^[25] (profile is 10 Hz): (a) Apparent resistivity; (b) phase. 模拟结果和 算法的结果^[25]对比(剖面为0.001 Hz)(a) 视电阻率; (b)相位

Fig. 10. Ellipsoidal model: (a) xy profile; (b) xz profile. 椭球体模型　(a) xy剖面; (b) xz剖面

Fig. 11. Slices of modelling results for ellipse model: (a) XY-mode apparent resistivities; (b) YX-mode apparent resistivities; (c) XY-mode phase; (d) YX-mode phase.椭球体模型模拟结果切片图　(a) XY模式视电阻率; (b) YX模式视电阻率; (c) XY模式相位; (d) YX模式相位

Fig. 12. Two-dimensional pure topographical model.二维纯地形模型

Fig. 13. Comparisions of three-dimensional and two-dimensional modelling results.三维和二维模拟结果对比

Fig. 14. Peak model and discretization using unstructured grids (the points in left diagram are survey line).山峰模型及其非结构化网格剖分(左图点为测线)

Fig. 15. Comparisions of three-dimensional and two-dimensional modelling results: (a), (b) Peak model; (c), (d) valley model.三维和二维模拟结果对比　(a), (b)山峰模型; (c), (d)山谷模型

Fig. 16. Comparisons of modelling results for different magnetic permeability: (a), (b) Model without electrical anomaly; (c), (d) model with electrical anomaly.不同磁导率模拟结果对比　(a), (b)无电性异常模型; (c), (d)含电性异常模型