存在复杂非均匀层的一维大地电磁正演

发布时间：2018-04-23 22:05

本文选题：大地电磁测深 + 非均匀层　；参考：《桂林理工大学学报》2016年04期

【摘要】：二、三维大地电磁(MT)正反演常采用一维反演结果作为初始迭代模型或利用一维模型响应定义边界条件,为进一步研究复杂地层条件下的MT响应,本文推导了非均匀层电导率随深度按线性-指数函数变化和指数-线性函数变化的一维MT正演的解析解形式,在此基础上对不同的地层组合情况进行讨论,分析了非均匀层埋深、厚度对MT响应的影响,并与地下介质均匀以及非均匀层电导率随深度按单一函数变化的MT响应进行对比。结果表明,既存在线性变化又存在指数变化的介质模型MT响应远比单一变化介质模型复杂,随着过渡层厚度增大、埋深变浅,其视电阻率和相位幅值与均匀介质模型响应幅值差异变大。
[Abstract]:Second, the forward and inverse modeling of 3D magnetotelluric magnetotelluric (MTT) usually uses one-dimensional inversion results as the initial iterative model or uses the one-dimensional model response to define boundary conditions, in order to further study the MT response in complex strata. In this paper, the analytical solutions of one dimensional MT forward modeling of the variation of conductivity with depth in linear exponential function and exponential linear function are derived. On the basis of this, different formation assemblages are discussed. The influence of the buried depth and thickness of the non-uniform layer on the MT response is analyzed and compared with that of the homogeneous layer in the underground medium and the single function of the conductivity of the non-uniform layer with the change of the depth. The results show that the MT response of the medium model with both linear and exponential variations is much more complex than that of the single medium model. With the increase of the thickness of the transition layer, the buried depth becomes shallower. The apparent resistivity and phase amplitude differ greatly from the response amplitude of homogeneous medium model.
【作者单位】：桂林理工大学地球科学学院;
【基金】：国家自然科学基金项目(41464002,41674075) 广西自然科学基金项目(2013GXNSFAA019277) 广西高校科研项目(2013YB107)
【分类号】：P631.325

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