A fast estimation method of magnetic-source parameters based on the vertical difference of normalized source strength
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摘要: 磁异常快速自动反演是磁数据解释的主要手段,归一化磁源强度因不受磁化方向影响而成为三维磁数据解释的主要方法。本文在归一化磁源强度基础上,首先进行了不同高度上的垂向差分计算,再根据不同高度差分关系,推导出了一种基于归一化磁源强度垂向差分的磁源参数快速反演方法。该方法可通过调节延拓高度来提高计算稳定性。模型试验表明归一化磁源强度垂向差分具有更高的异常分辨率,极大值能够有效地识别场源水平位置,而快速反演方法则较好地获取了场源的深度与构造指数。将本文方法应用于内蒙古M区地面磁异常之中,获得了磁源的平面展布和深度及构造指数信息,为研究区隐伏岩体分布提供了依据。Abstract: Fast automatic inversion is a primary tool for magnetic data interpretation. The normalized source strength (NSS) is one main method for three-dimensional magnetic data interpretation as it is independent of magnetization direction. In this paper, the vertical difference of the normalized source of strength is introduced, and a fast estimation method of magnetic-source parameters based on the vertical difference of normalized source strength is derived in the light of the vertical difference of NSS at different height. In addition, upward continuation of suitable height can be used to improve the stability of the method. Model tests shows that the vertical difference of NSS has higher resolution ability and can recognize the horizontal locations of magnetic sources, and the proposed automatic inversion method can obtain the depths and structural indices of the sources. In this paper, the proposed method is applied to magnetic anomaly of M area over Inner Mongolia, and obtain the horizontal locations, depths and structural indices of magnetic sources. The results could provide useful information for forecasting the distribution of concealed rock mass.
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[1] Peters L J. The direct approach to magnetic interpretation and its practical application[J]. Geophysics, 1949, 14(3):290-320.
[2] Thompson D T. EUDPH: A new technique for making computer assisted depth estimates from magnetic data[J]. Geophysics, 1982, 47(1):31-37.
[3] Reid A B, Allsop J M, Granser H, et al. Magnetic interpretation in three dimensions using Euler deconvolution[J]. Geophysics, 1990, 55(1):80-91.
[4] Zhang C Y, Mushayandebvu M F, Reid A B, et al. Euler deconvolution of gravity tensor gradient data[J]. Geophysics, 2000, 65(2):512-520.
[5] Huang D, Gubbins D, Clark R A, et al. Combined study of Euler's homogeneity equation for gravity and magnetic field[C]// Extended Abstracts of 57th EAGE Conference, Glasgow, UK, 1995: 144.
[6] Salem A, Ravat D. A combined analytic signal and Euler method (AN-EUL) for automatic interpretation of magnetic data[J]. Geophysics, 2003, 68(6):1952-1961.
[7] Salem A, Williams S, Fairhead D, et al. Interpretation of magnetic data using tilt-angle derivatives[J]. Geophysics, 2008, 71(1):1-10.
[8] 马国庆, 杜晓娟, 李丽丽. 解释位场全张量数据的张量局部波数法及其与常规局部波数法的比较[J]. 地球物理学报, 2012, 55(7):2450-2461.
[9] Ma G Q, Du X J, Li L L. Comparison of the tensor local wavenumber method with the conventional local wavenumber method for interpretation of total tensor data of potential fields[J]. Chinese Journal of Geophysics, 2012, 55(7):2450-2461.
[10] Atchuta R D, Ram-Babu H V, Sanker-narayan P V. Interpretation of magnetic anomalies due to dikes: The complex gradient method[J]. Geophysics, 1981, 46(11):1572-1578.
[11] Macleod I N, Jones K, Dai T F. 3-D analytic signal in the interpretation of total magnetic field data at low magnetic latitudes[J]. Exploration Geophysics, 1993, 24:679-688.
[12] Salem A, Ravat D, Mushayandebvu M F, et al. Linearized least-squares method for interpretation of potential-field data from sources of simple geometry[J]. Geophysics, 2004, 69(3):783-788.
[13] Salem A. Interpretation of magnetic data using analytic signal derivatives[J]. Geophysical Prospecting, 2005, 53:75-82.
[14] Ma G Q, Du X J. An improved analytic signal technique for the depth and structural index from 2D magnetic anomaly data[J]. Pure and Applied Geophysics, 2012, 169:2193-2200.
[15] Cooper G R J. The automatic determination of the location and depth of contacts and dykes from aeromagnetic data[J]. Pure and Applied Geophysics, 2014, 171:2417-2423.
[16] Cooper G R J. Using the analytic signal amplitude to determine the location and depth of thin dikes from magnetic data[J]. Geophysics, 2015, 80(1):J1-J6.
[17] Cooper G R J, Whitehead R C. Determining the distance to magnetic source[J]. Geophysics, 2016, 81(2):J25-J34.
[18] Cooper G R J. Determining the depth and location of potential field sources without specifying the structural index[J]. Arabian Journal of Geoscience, 2017, 10(438):1-7.
[19] Wang Y G, Luo X, Zhang J. Interpretation of 2D magnetic sources based on the reciprocal of the analytic signal amplitude[J]. Exploration Geophysics, 2019, 50(6):645-652.
[20] Salem A, Williams S E, Fairhead J D, et al. Tilt-depth method: A simple depth estimation method using fi rst-order magnetic derivatives[J]. The Leading Edge, 2007, 26(12):1502-1505.
[21] Fairhead J D, Salem A, Cascone L, et al. New development of the magnetic tilt-depth method to improve structural mapping of sedimentary basins[J]. Geophysical Prospecting, 2011, 59:1072-1086.
[22] 张恒磊, Marangoni Y R, 左仁广, 等. 改进的各向异性标准化方差探测斜磁化磁异常源边界[J]. 地球物理学报, 2014, 57(8):2724-2731.
[23] Zhang H L, Marangoni Y R, Zuo R G, et al. The improved anisotropy normalized variance for detecting non-vertical magnetization anomalies[J]. Chinese Journal of Geophysics, 2014, 57(8):2724-2731.
[24] Wang Y G, Zhang J, et al. Improved tilt-depth method for fast estimation of top and bottom depths of magnetic bodies[J]. Applied Geophysics, 2016, 13(2):249-256.
[25] Cooper G R J. Applying the tilt-depth and contact-depth methods to the anomalies of thin dykes[J]. Geophysical Prospecting, 2017, 65:316-323.
[26] 曹伟平, 王彦国, 杨博 等. Tilt-depth 方法适用性研究及其应用[J]. 世界地质, 2017, 36(2):560-569.
[27] Cao W P, Wang Y G, Yang B, et al. Applicability of tilt-depth method and its application[J]. World Geology, 2017, 36(2):560-569.
[28] Wilson H S. Analysis of the magnetic gradient tensor[J]. Canada Technical Memorandum, 1985, 8:5-13.
[29] Beiki M, Clark D A, Austin J R, et al. Estimating source location using normalized magnetic source strength calculated from magnetic gradient tensor data[J]. Geophysics, 2012, 77(6):J23-J37.
[30] Pikington M, Beiki M. Mitigating remanent magnetization effects in magnetic data using the normalized source strength[J]. Geophysics, 2013, 78(3):J25-J32.
[31] Guo L H, Meng X H, Zhang G L. Three-dimensional imaging for total amplitude magnetic anomaly and normalized source strength in the presence of strong remanent magnetization[J]. Journal of Applied Geophysics, 2014, (111):121-128.
[32] 饶椿锋, 于鹏, 胡书凡, 等. 基于加权模型参数的归一化磁源强度三维反演[J]. 石油物探, 2017, 56(4):599-606.
[33] Rao C F, Yu P, Hu S F, et al. The 3D inversion of the normalized source strength data based on weighted model parameters[J]. Geophysical Prospecting for Petroleum, 2017, 56(4):599-606.
[34] Blakely R J. Potential theory in gravity and magnetic applications [M]. London: Cambridge University Press, 1995.
[35] Pedersen L B, Rasmussen T M. The gradient tensor of potential field anomalies: Some implications on data collection and data processing of maps[J]. Geophysics, 1990, 55(12):1558-1566.
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