Document Type : Original Research Paper
Authors
1 Institute of Geophysics, University of Tehran, Tehran, Iran.
2 Dept. of Earth Sciences, Free University of Berlin, Berlin, German .
3 Dept. of Earth Sciences, Free University of Berlin, Berlin, German
Abstract
Investigations made in current study illustrate that an application of 2-D isotropic inversion algorithm for magnetotelluric data affected by anisotropy could recover macro-anisotropy reasonably well. First anisotropy effects on common MT interpretation steps, dimensionality analysis and 2-D inversion modeling, are investigated. Two kinds of azimuthally anisotropic features (anisotropic block and anisotropic layer) which generally form a part of 2-D models are considered. The influence of different anisotropy strikes and resistivity contrasts on dimensionality analysis and on the behavior of induction arrows is studied. These investigations evince that, a strike direction close to the anisotropy strike can be chosen by the dimensionality analysis of the data. Then if the data are rotated to this angle, 2-D inversion would recover the anisotropy sensibly by means of macro-anisotropy. This procedure is tested successfully on a field data set where anisotropy had been previously recognized. The results show that the proposed approach reproduces the anisotropy acceptably via macro-anisotropy in the final inversion model.
Keywords
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