Abstract
Magnetic anomalies are often disturbed by the magnetization direction, so we can’t directly use the original magnetic anomaly to estimate the exact location and geometry of the source. The 2D analytic signal is insensitive to magnetization direction. In this paper, we present an automatic method based on the analytic signal horizontal and vertical derivatives to interpret the magnetic anomaly. We derive a linear equation using the analytic signal properties and we obtain the 2D magnetic body location parameters without giving a priori information. Then we compute the source structural index (expressing the geometry) by the estimated location parameters. The proposed method is demonstrated on synthetic magnetic anomalies with noise. For different models, the proposed technique can both successfully estimate the location parameters and the structural index of the sources and is insensitive to noise. Lastly, we apply it to real magnetic anomalies from China and obtain the distribution of unexploited iron ore. The inversion results are consistent with the parameters of known ore bodies.
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This work is supported by the Special Investigation and Assessment of Geological Mineral Resources of the China Geological Survey (No. GZH003-07-03)
Ma Guo-Qing graduated from Jilin University in 2008 with a bachelor degree in Geophysics. He received a Master’ s degree in Solid Geophysics from Jilin University in 2010. He is currently studying his PhD in the Jilin University. His research interests include the processing and interpretation of potential fields.
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Ma, GQ., Du, XJ., Li, LL. et al. Interpretation of magnetic anomalies by horizontal and vertical derivatives of the analytic signal. Appl. Geophys. 9, 468–474 (2012). https://doi.org/10.1007/s11770-012-0350-4
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DOI: https://doi.org/10.1007/s11770-012-0350-4