Correction of magnetotelluric static shift by analysis of 3D forward modelling and measured test data
Kun Zhang 1 2 7 Wenbo Wei 3 Qingtian Lu 4 Huafeng Wang 5 Yawei Zhang 6
+ Author Affiliations
- Author Affiliations
1 Institute of Mineral Resources, Chinese Academy of Geological Sciences, MLR Key Laboratory of Metallogeny and Mineral Assessment, Beijing 100037, China.
2 Institude of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
3 School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China.
4 Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China.
5 Shandong Institute of Geophysical and Geochemical Exploration, Jinan, Shandong 250000, China.
6 School of Nuclear Engineering and Geophysics, East China Institute of Technology, Nanchang 330013, China.
7 Corresponding author. Email: zhangkun1010@163.com
Exploration Geophysics 47(2) 100-107 https://doi.org/10.1071/EG14044
Submitted: 28 April 2014 Accepted: 13 May 2015 Published: 12 June 2015
Abstract
To solve the problem of correction of magnetotelluric (MT) static shift, we quantise factors that influence geological environments and observation conditions and study MT static shift according to 3D MT numerical forward modelling and field tests with real data collection. We find that static shift distortions affect both the apparent resistivity and the impedance phase. The distortion results are also related to the frequency. On the basis of synthetic and real data analysis, we propose the concept of generalised static shift resistivity (GSSR) and a new method for correcting MT static shift. The approach is verified by studying 2D inversion models using synthetic and real data.
Key words: 3D forward modelling, correction method, field test, MT static shift, sounding analysis.
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