The magnetotelluric response over 2D media with resistivity frequency dispersion
- Univ. Federico II, Napoli (Italy). Dept. of Geophysics and Volcanology
- CNR Inst. of Marine Geology, Napoli (Italy)
The authors investigate the magnetotelluric response of two-dimensional bodies, characterized by the presence of low-frequency dispersion phenomena of the electrical parameters. The Cole-Cole dispersion model is assumed to represent the frequency dependence of the impedivity complex function, defined as the inverse of Stoyer`s admittivity complex parameter. To simulate real geological situations, they consider three structural models, representing a sedimentary basin, a geothermal system and a magma chamber, assumed to be partially or totally dispersive. From a detailed study of the frequency and space behaviors of the magnetotelluric parameters, taking known non-dispersive results as reference, they outline the main peculiarities of the local distortion effects, caused by the presence of dispersion in the target media. Finally, they discuss the interpretive errors which can be made by neglecting the dispersion phenomena. The apparent dispersion function, which was defined in a previous paper to describe similar effects in the one-dimensional case, is again used as a reliable indicator of location, shape and spatial extent of the dispersive bodies. The general result of this study is a marked improvement in the resolution power of the magnetotelluric method.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 390077
- Journal Information:
- Geophysical Prospecting, Vol. 44, Issue 5; Other Information: PBD: Sep 1996
- Country of Publication:
- United States
- Language:
- English
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