Robust magnetotelluric inversion
Chave, Alan D.
Jones, Alan G.
Muller, Mark R.
Evans, Rob L.
MetadataShow full item record
A robust magnetotelluric (MT) inversion algorithm has been developed on the basis of quantile-quantile (q-q) plotting with confidence band and statistical modelling of inversion residuals for the MT response function (apparent resistivity and phase). Once outliers in the inversion residuals are detected in the q-q plot with the confidence band and the statistical modelling with the Akaike information criterion, they are excluded from the inversion data set and a subsequent inversion is implemented with the culled data set. The exclusion of outliers and the subsequent inversion is repeated until the q-q plot is substantially linear within the confidence band, outliers predicted by the statistical modelling are unchanged from the prior inversion, and the misfit statistic is unchanged at a target level. The robust inversion algorithm was applied to synthetic data generated from a simple 2-D model and observational data from a 2-D transect in southern Africa. Outliers in the synthetic data, which come from extreme values added to the synthetic responses, produced spurious features in inversion models, but were detected by the robust algorithm and excluded to retrieve the true model. An application of the robust inversion algorithm to the field data demonstrates that the method is useful for data clean-up of outliers, which could include model as well as data inconsistency (for example, inability to fit a 2-D model to a 3-D data set), during inversion and for objectively obtaining a robust and optimal model. The present statistical method is available irrespective of the dimensionality of target structures (hence 2-D and 3-D structures) and of isotropy or anisotropy, and can operate as an external process to any inversion algorithm without modifications to the inversion program.
Author Posting. © The Author(s), 2014. This article is posted here by permission of The Royal Astronomical Society for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 196 (2014): 1365-1374, doi:10.1093/gji/ggt484.
Suggested CitationArticle: Matsuno, Tetsuo, Chave, Alan D., Jones, Alan G., Muller, Mark R., Evans, Rob L., "Robust magnetotelluric inversion", Geophysical Journal International 196 (2014): 1365-1374, DOI:10.1093/gji/ggt484, https://hdl.handle.net/1912/6534
Showing items related by title, author, creator and subject.
Baba, Kiyoshi; Chave, Alan D. (American Geophysical Union, 2005-12-14)The large contrast in electrical conductivity between seawater and the underlying seafloor accumulates boundary electric charges which can severely distort observed electric and magnetic fields. For marine magnetotelluric ...
Conductivity structure of the lithosphere-asthenosphere boundary beneath the eastern North American margin Attias, Eric; Evans, Rob L.; Naif, Samer; Elsenbeck, James R.; Key, Kerry (John Wiley & Sons, 2017-02-25)Tectonic plate motion and mantle dynamics processes are heavily influenced by the characteristics of the lithosphere-asthenosphere boundary (LAB), yet this boundary remains enigmatic regarding its properties and geometry. ...
Baba, Kiyoshi; Tarits, Pascal; Chave, Alan D.; Evans, Rob L.; Hirth, Greg; Mackie, Randall L. (American Geophysical Union, 2006-11-16)The electrical structure of the upper mantle beneath the East Pacific Rise (EPR) at 15°45′S is imaged by inverting seafloor magnetotelluric data obtained during the Mantle ELectromagnetic and Tomography (MELT) experiment. ...