| 摘要 |
A three-dimensional display and interpretation technique, in which magnetotelluric survey and modeling data are transformed and compared in order to yield a remotely determined picture of subsurface rock properties and structure, is disclosed. Normalized transfer functions for the magnetotelluric fields are displayed, as normalized impedance polar diagrams, properly oriented at appropriate probing depths using a logarithmic vertical coordinate. The form of these and other normalized polar diagrams provide geologic information on local-structure dimensionality. Colors are derived and assigned to particular azimuthal segments of the normalized impedance polar diagrams in order to identify rock properties in particular directions at depth. This unique combination results in structural and rock property information being simultaneously displayed in a single trace. Null readings from a differential display are used to indicate correspondence between field survey impedance measurements and measurements derived from numerical analysis of a model. Time is used to model diffusion of magnetotelluric energy into the ground as well as to identify differing wave components. Colored geologic sections, fence diagrams, etc., can be generated in real-time by this display and analysis technique from standard magnetotelluric data sets.
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