Please use this identifier to cite or link to this item:
|Title:||Three-dimensional inversion of magnetotelluric impedance tensor data and full distortion matrix.|
Moorkamp, U. Max S.
|Publisher:||Oxford University Press (OUP), Royal Astronomical Society|
|Citation:||Geophysical Journal International (2015) 202, 464–481|
|Abstract:||Galvanic distortion of magnetotelluric (MT) data due to small-scale surficial bodies or due to topography is one of the major factors that prevents accurate imaging of the subsurface. We present a three-dimensional algorithm for joint inversion of MT impedance tensor data and a frequency-independent full distortion matrix that circumvents this problem. We perform several tests of our algorithm on synthetic data affected by different amounts of distortion. These tests show that joint inversion leads to a better conductivity model compared to the inversion of the MT impedance tensor without any correction for distortion effects. For highly distorted data, inversion without any distortion correction results in strong artefacts and we cannot fit the data to the specified noise level. When the distortion is reduced, we can fit the data to an RMS of one, but still observe artefacts in the shallow part of the model. In contrast, in both cases our joint inversion can fit the data within the assumed noise and the resulting models are comparable to the inversion of undistorted data. In addition, we show that the elements of the full distortion matrix can be well resolved by our algorithm. Finally, when inverting undistorted data, including the distortion matrix in the inversion only results in a minor loss of resolution. We therefore consider our new approach a promising tool for the general analysis of real field data.|
|Version:||Published version (Publisher PDF)|
|Rights:||This article has been accepted for publication in Geophysical Journal International ©: 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.|
|Appears in Collections:||Published Articles, Dept. of Geology|
Files in This Item:
|Geophys. J. Int.-2015-Avdeeva-464-81.pdf||Publisher version||7.47 MB||Adobe PDF||View/Open|
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.