Rapid inversion of two‐ and three‐dimensional magnetotelluric data

We have developed an efficient iterative inversion method applicable to both two-dimensional (2D) and three-dimensional magnetotelluric data. The method approximates horizontal derivative terms with their values calculated from the fields of the previous iteration. The equations at each horizontal coordinate then become uncoupled. At each iteration this allows separate inversions for the improved conductivity profile beneath each measurement site. Resultant profiles are interpolated to form a new multidimensional model for which the fields for the next iteration are calculated. The method is extremely fast, and tests with 2D data show very promising results.

[1]  P. Weidelt,et al.  Inversion of two-dimensional conductivity structures , 1975 .

[2]  C. R. Brewitt-Taylor,et al.  On the finite difference solution of two-dimensional induction problems , 1976 .

[3]  W. Rodi.  A Technique for Improving the Accuracy of Finite Element Solutions for Magnetotelluric Data , 1976 .

[4]  D. Brandt,et al.  Multi-level adaptive solutions to boundary-value problems math comptr , 1977 .

[5]  David L.B. Jupp,et al.  Two-dimensional magnetotelluric inversion , 1977 .

[6]  D. Kershaw.  The incomplete Cholesky—conjugate gradient method for the iterative solution of systems of linear equations , 1978 .

[7]  D. Oldenburg.  One-dimensional inversion of natural source magnetotelluric observations , 1979 .

[8]  R. Parker.  The inverse problem of electromagnetic induction: Existence and construction of solutions based on incomplete data , 1980 .

[9]  G. Pavlis,et al.  The mixed discrete‐continuous inverse problem: Application to the simultaneous determination of earthquake hypocenters and velocity structure , 1980 .

[10]  P.K.W. Vinsome,et al.  Block iterative methods for fully implicit reservoir simulation , 1982 .

[11]  George E. Backus,et al.  Harmonic splines for geomagnetic modelling , 1982 .

[12]  Gary L. Pavlis,et al.  Progressive multiple event location (PMEL) , 1983 .

[13]  D. Oldenburg,et al.  Inversion of ocean bottom magnetotelluric data revisited , 1984 .

[14]  Gerald W. Hohmann,et al.  Magnetotelluric responses of three-dimensional bodies in layered earths , 1982 .

[15]  Philip E. Wannamaker,et al.  Two-dimensional topographic responses in magnetotellurics modeled using finite elements , 1986 .

[16]  R. Parker,et al.  Occam's inversion; a practical algorithm for generating smooth models from electromagnetic sounding data , 1987 .

[17]  Alan G. Jones,et al.  Static shift of magnetotelluric data and its removal in a sedimentary basin environment , 1988 .

[18]  J. T. Smith,et al.  Magnetotelluric inversion for minimum structure , 1988 .

[19]  R. L. Mackie,et al.  Three-dimensional magnetotelluric modelling and inversion , 1989, Proc. IEEE.

[20]  S. Constable,et al.  Occam's inversion to generate smooth, two-dimensional models from magnetotelluric data , 1990 .