We present in this work the bidimensional Magnetotelluric method modelling with arbitrary anisotropy in the electrical conductivity for horizontally stratified multilayers models,
separating the total field into primary and secondary fields. The primary field is the 1D
MT field in the absence of heterogeneity. The secondary field is the field generated by the
heterogeneity, in other words, it is the difference between the total field and the primary
field. The numerical technique of Finite Elements (FE) is used for this 2D Modelling. In
addition we include the MT 1D modelling case with arbitrary 3D conductivity anistropy
using the propagation matrix method. This result is used as the source in the bidimensional
formulation. When we studied the horizontal fields in layered media; there seems to exist
sources in each anisotropic layer, because there is an increase of amplitude in these layers,
also we verify the appearence of the normal component Ez of the field, without a current
density in this direction. The arbitrary anisotropy allows the principals anisotropic axes
to have any orientation in relation to cartesian referencial system choosen for the problem.
This orientation is defined by three consecutive rotations, the first being strike, the second
dip and the third slant. These rotations simulate common geological environments in the
earth. This type of anisotropy changes the pseudo-sections of apparent resistivity, making
data interpretation more challenging.
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