(a) Location of the used IMAGE magnetic stations (blue and pink dots) and the corresponding shifted locations in Sweden (black dots) at the same geographic latitude, and the west, central, and east longitudes of the Swedish region at that latitude. Equal quasi-dipole geomagnetic latitudes (at 0 km) for the years 2000 and 2018 are presented along each station with blue and light-blue colors, respectively. (b–d) Horizontal distribution of the conductance S(x,y) for three sheets at different depths of thickness (D) developed by Korja et al. (2002). (b) The first layer (D₁ = 0–10 km) corresponds to the upper crust, which includes the surface, seawater, and sediment. (c) The second layer (D₂ = 10–30 km) corresponds to the middle crust. (d) The third layer (D₃ = 30–60 km) corresponds to the lower crust. In all panels, the black dots indicate three equidistant locations (west, center, east) in Sweden at the same geographic latitude as the selected stations in color blue. Figure adapted from Lanabere et al. (2023).