Joint inversion of magnetotelluric and fullwaveform seismicdata based on alternating cross-gradient structural constraints

doi:10.3969/j.issn.1673-9736.2020.02.06

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Global Geology ›› 2020, Vol. 23 ›› Issue (2) : 123-134. DOI: 10.3969/j.issn.1673-9736.2020.02.06

Joint inversion of magnetotelluric and fullwaveform seismicdata based on alternating cross-gradient structural constraints

QI Jiahui, FENG Xuan, Enhedelihai Nilot, LI Xiaodan

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Abstract

Magnetotelluric (MT) inversion and seismic inversion are important methods for the interpretation of subsurface exploration data, but separate inversion of MT and seismic produces ambiguous and non-unique results due to various factors. In order to achieve accurate results, the authors propose a joint inversion method of two-dimensional MT and seismic data in the frequency domain. The finite element method is used for numerical simulation of electromagnetic data in the forward modelling, and the Gauss-Newton method is used for the inversion. The 9-point-finite-difference method is used to solve the seismic wave field in the acoustic wave equation, and the inverse problem of seismic data is solved by full waveform inversion with a conjugate gradient, a simple and fast method. Cross gradient functions are used to provide constraint structure between resistivity and velocity parameters to carry out the joint inversion. The joint inversion algorithm is tested by double-rectangular model synthesis data, and the accuracy of the algorithm is verified. The results show that the joint inversion results are better than those from separate inversion. The algorithm is applied to a geophysical model of a metalliferous deposit in Jinchuan and is compared with the separate inversion results. It shows that the results obtained with joint inversion are much closer to the real model.

Key words

alternating joint inversion / structural constraint / MT inversion / FWI

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QI Jiahui, FENG Xuan, Enhedelihai Nilot, LI Xiaodan. Joint inversion of magnetotelluric and fullwaveform seismicdata based on alternating cross-gradient structural constraints[J]. Global Geology. 2020, 23(2): 123-134 https://doi.org/10.3969/j.issn.1673-9736.2020.02.06

References

Bae H S, Pyun S, Chung W,et al. 2012. Frequency-domain acoustic-elastic coupled waveform inversion using the Gauss-Newton conjugate gradient method,Geophysical Prospecting,60(3):413-432.
Bennington N L, Zhang H J, Thurber C H, et al. 2015. Joint inversion of seismic and magnetotellursion data in the Parkfield region of California using the normalized cross-gradient constraint.Pure and Applied Geophysics,172(5):1033-1052.
Cagniard L. 1953. Basic theory of the magneto-telluric method of geophysical prospecting.Geophysics,18(3):605-635.
Colombo D, Stefano M D. 2007. Geophysical modeling via simultaneous joint inversion of seismic, gravity, and electromagnetic data:Application to prestack depth imaging.Leading Edge,26(3):326-331.
Feng X, Ren Q C, Liu C,et al. 2017. Joint acoustic full-waveform inversion of crosshole seismic and ground-penetrating radar data in the frequency domain.Geophysics,82(6):H41-H56.
Feng X, Enhedelihai Nilot, Liu C,et al. 2018. Joint inversion of seismic and audio magnetotelluric data with structural constraint for metallic deposit.Journal of Environmental and Engineering Geophysics,23(2):159-169.
Gallardo L A, Meju M A. 2003. Characterization of heterogeneous near-surface materials by joint 2D inversion of dc resistivity and seismic data.Geophysical Research Letters,30(13):I1-4.
Gallardo L A, Meju M A. 2004. Joint two-dimensional DC resistivity and seismic travel time inversion with cross-gradients constraints.Journal of Geophysical Research-Solid Earth,109(B3):B03311-11.DOI:10.1029/2003JB002716.
Gallardo L A, Meju M A. 2007. Joint two-dimensional cross-gradient imaging of magnetotelluric and seismic travel time data for structural and lithological classification.Geophysical Journal International,169(3):1261-1272.
Gao J, Zhang H J. 2016. Two-dimensional joint inversion of seismic velocity and electrical resistivity using seismic travel times and full channel electric measurements based on alternating cross-gradient structural constraint. Chinese Journal of Geophysics,59(11):4310-4322. (in Chinese with English abstract)
Heincke B, Jegen M, Hobbs R. 2006. Joint inversion of MT, gravity and seismic data applied to sub-basalt imaging.SEG Technical Program Expanded Abstracts,25(1):784-789.
Hu X Y, Yang D K, Liu S H,et al. 2006. The developing trends of environmental and engineering geophysics.Progress in Geophysics,21(2):598-604. (in Chinese with English abstract)
Jegen M D, Richard W H, Pascal T, et al. 2009. Joint inversion of marine magnetotelluric and gravity data incorporating seismic constraints:preliminary results of sub-basalt imaging off the Faroe Shelf.Earth and Planetary Science Letters,282(1):47-55.
Jo C H, Suh J H, Shin C S. 1996. An optimal 9-point, finite-difference, frequency-space, 2-D scalar wave extrapolator.Geophysics,61(2):529-537.
Jupp D L B, Vozoff K. 1975. Stable iterative methods for the inversion of geophysical data.Geophysical Journal of the Royal Astronomical Society,42(3):957-976.
Moorkamp M, Heincke B, Jegen M,et al. 2011. A framework for 3-D joint inversion of MT, gravity and seismic refraction data.Geophysical Journal International,184(1):477-493.
Peng M, Tan H D, Jiang M,et al. 2013. Three-dimensional joint inversion of magnetotelluric and seismic travel time data with cross-gradient constraints.Chinese Journal of Geophy-sics,56(8); 2728-2738. (in Chinese with English abstract).
Pratt R G. 1990. Frequency-domain elastic wave modeling by finite differences:a tool for crosshole seismic imaging.Geophysics,55(5):626-632.
Pratt R G, Shin C, Hick G J. 1998. Gauss-Newton and full Newton methods in frequency-space seismic waveform inversion.Geophysical Journal International,133(2):341-362.
Rodi W L. 1976. A technique for improving the accuracy of finite element solutions for magnetotelluric data.Geophysical Journal of the Royal Astronomical Society,44(2):483-506.
Tarantola A. 1984. Inversion of seismic reflection data in the acoustic approximation.Geophysics,49(8):1259-1266.
Vigh D, Starr E W. 2008. Comparisons for waveform inversion, time domain or frequency domain.SEG Technical Program Expanded Abstracts,27(1):1890-1894.
Yao Y. 2002. Basic theory and application methods of geophysical inversion. Wuhan:China University of Geosciences Press, 1-138. (in Chinese).
Zhang R Z. 2017. The study of two-dimensional joint inversion of gravity, magnetic, electrical and seismic based on the cross-gradient constrains and its application:master's degree thesis. Changchun:Jilin University. (in Chinese with English abstract)