球坐标系变密度界面正演及反演方法研究  

Study on forward modeling and inversion of variable densityinterface under spherical coordinate system

作　　者：崔亚彤 王胜侯 CUI Yatong;WANG Shenghou(Tianjin Survey Design Institute Group Co.,Ltd,Tianjin 300191,China;China University of Geosciences(Wuhan)School of Earth Resources,Wuhan 430074,China)

机构地区：[1]天津市勘察设计院集团有限公司,天津300191 [2]中国地质大学(武汉)资源学院,武汉430074

出　　处：《物探化探计算技术》2023年第3期351-359,共9页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：密度界面反演方法可推断构造界面起伏形态,对于分析区域地质构造、地球深部构造和划分构造单元具有重要意义。当涉及到区域性乃至全球尺度问题时,通常采用球坐标系的密度界面反演方法。传统球坐标系密度界面反演方法在地表观测面的计算精度较低,且未能考虑地下密度的纵横向变化。这里针对上述问题,开展球坐标系变密度界面正演及反演方法研究,通过理论推导和高斯-勒让德积分算法改进,给出球坐标系变密度界面高精度正演方法,运用迭代优化算法而给出球坐标系变密度界面反演方法。最后利用球壳模型和起伏界面数据试验验证该方法的有效性,适用于大区域、地表观测面的变密度界面反演。The inversion method of density interface can infer the undulation morphology of the tectonic interface,which is of great significance to analyzing regional geological structure,deep earth structure,and the division of tectonic units.When regional and global scale problems are involved,the interface inversion method is often used under the spherical coordinate system.However,the traditional inversion method under the spherical coordinate system has low calculation accuracy on the observational ground surface and neglects the density variations vertical and horizontal underground.In this paper,aiming at these problems,we develop an approach of variable density interface inversion under the spherical coordinate system for the ground observation data.First,based on the theoretical derivation and the improvement of the Gauss-Legendre integral algorithm,we present the approach for forward modeling of variable density interface under the spherical coordinate system.Then we develop a density interface inversion method under the spherical coordinate system based on the iterative optimization algorithm.Finally,tests on a shell model and undulated interface show that our approach is practical and suitable for the variable density interface inversion of large-area and ground observation data.

关 键 词：重力异常 球坐标系 变密度界面正演 变密度界面反演 

分 类 号：P631.1[天文地球—地质矿产勘探]