Fig. 13

Anisotropic homogeneous model. Computational grid, showing the discretization of the homogeneous anisotropic Earth model. Blue color corresponds to the air domain, and the red color corresponds to the anisotropic subsurface with the diagonal conductivity tensor defined in Eq. (32).The input model was extended 50 km downwards in \({\mathbf {z}}\)-direction, increasing the depth to 100 km before the extension zone. The air height is 10 km. A spacing of \(\text{d}x=\text{d}y=\text{d}z=7\) km has been chosen. The extension zone has a width of 191 km for all directions. The computational grid has dimensions of \(x,y\in [-241.1,239.1]\) km, and \(z\in [0,442.2]\) km