Linking strike directions to invariant TE and TM impedances of the magnetotelluric impedance tensor

Abstract Estimation of the traditional transverse electric (TE) and magnetic (TM) impedances magnetotelluric tensor for two-dimensional structures can be decoupled from estimation strike direction with significant implications when dealing galvanic distortions. Distortion-free data are obtainable by combining a quadratic equation phase tensor. In terminology Groom–Bailey, provides amplitudes phases that immune to twist, both, twist shear. On other hand, distortion-free directions obtained using Bahr's approach or principle, this is all needed proceed (2D) interpretation. However, resulting ignorant because they invariant under coordinate system rotation, if related geological strike, must linked particular direction. This an additional ambiguity one 90° arising in classic strike-determination methods, which resolved independently. work, we use distortion model Groom–Bailey resolve bringing back coupling between presence Our hybrid existing numerical analytical methods reduces problem binary decision, involves associating correct TE TM modes. To determine appropriate association, present three algorithms. Two them require optimizing fit data, third requires comparison phases. All keep track possible crossings curves providing clear-cut solution. Synthetic field illustrate performance schemes. Graphical