考虑地表起伏的不规则区域重力梯度场模型构建方法——以云南地区为例  

STUDY ON THE REGIONAL GRAVITY GRADIENT FIELD MODELING IN IRREGULAR AREA WITH CONSIDERATION OF SURFACE FLUCTUATION:A CASE STUDY OF YUNNAN PROVINCE

作　　者：刘金钊[1,2] 梁星辉 叶周润 陈兆辉 胡敏章[4] 韩宇飞[5] 王青华 刘东[6] 郝洪涛 张双喜[1] 陈铭[1] LIU Jin-zhao;LIANG Xing-hui;YE Zhou-run;CHEN Zhao-hui;HU Min-zhang;HAN Yu-fei;WANG Qing-hua;LIU Dong;HAO Hong-tao;ZHANG Shuang-xi;CHEN Ming(The First Monitoring and Application Center,China Earthquake Administration,Tianjin 300180,China;State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology.Chinese Academy of Science,Wuhan 430077,China;Hefei University of Technology,Hefei 230009,China;Key Laboratory of Earthquake Geodesy,Institute of Seismology,China Earthquake Administration,Wuhan 430071,China;China Earthquake Networks Center,Beijing 100045,China;Yunnan Earthquake Administration,Kunming 650224,China)

机构地区：[1]中国地震局第一监测中心,天津300180 [2]中国科学院精密测量科学与技术创新研究院,大地测量与地球动力学国家重点实验室,武汉430077 [3]合肥工业大学,合肥230009 [4]中国地震局地震研究所,地震大地测量重点实验室,武汉430071 [5]中国地震台网中心,北京100045 [6]云南省地震局,昆明650224

出　　处：《地震地质》2023年第5期1129-1146,共18页Seismology and Geology

基　　金：国家自然科学基金(41704084,41904010);安徽省基金(2008085MD115)共同资助

摘　　要：文中推导并给出了基于非格网分布的起伏面扰动重力或重力异常解算区域扰动重力梯度场模型的数值计算公式。基于澳大利亚West Arnhem Land地区的格网重力数据,以频谱域(二维快速傅里叶变换)解算的扰动重力梯度全张量作为“基准值”,然后利用基于推导公式的最小二乘配置方法(LSC)对相同区域非规则范围的重力数据进行扰动重力梯度模型解算,将结果作为“评估值”。对比“基准值”与“评估值”之差,研究发现:1)基于推导公式的最小二乘配置方法解算得到的扰动重力梯度值与频谱域方法得到扰动梯度“基准值”各分量在空间形变变化上是一致的;2)统计扰动重力梯度各分量的差值ΔδΓ_(xx)^(fft-lsc)、ΔδΓ_(xy)^(fft-lsc)、ΔδΓ_(xz)^(fft-lsc)、ΔδΓ_(yy)^(fft-lsc)、ΔδΓ_(yz)^(fft-lsc)和ΔΓ_(zz)^(fft-lsc)“基准值”与“评估值”差值的标准差分别为5.54E、5.30E、1.85E、6.55E、2.09E和9.67E(1E=1×10^(-9)s^(-2)),远低于国际上实测重力梯度与解算模型差值的研究结果。最后,基于云南地区实测地表差分重力值,文中首次给出了该区域半波长约20km的重力梯度场年际变化模型。文中的思路和方法提高了广泛分布的重力数据(主要为重力异常和扰动重力)的使用效率,可为地球物理学、地质学研究更好地理解和解释重力数据、重力梯度数据及其与场源的关系提供数据基础。The gravity gradient full tensor can sense the slight changes of the gravity vector in different directions,and because of the large number of components(6 components),it can reflect more information on different sides of the same field source than the gravity vector.On the other hand,the ground gravity survey has accumulated a lot of basic gravity vector data,and using the mathematical relationship between the gravity vector and the full tensor of gravity gradient to build a full tensor gravity gradient field model is helpful to the depth mining of existing gravity data information.Based on the mathematical relation and covariance function relation of disturbance potential,gravity anomaly,gravity disturbance and gravity gradient disturbance,along with the Least Square Configuration(LSC)algorithm,in this paper,the numerical formulas have been derived in detail for modeling the full tensor of regional gravity gradient disturbance field from gravity disturbance or gravity anomaly which distributed on undulating surface with non-grid pattern.The full tensor of gravity gradient derived from the grid distributed gravity anomaly data in West Arnhem Land,Australia by using the spectral domain(two-dimensional fast Fourier transform)method were taken as the“reference value”,Then,the full tensor of gravity gradient,in the same area with irregular regional gravity data distribution,derived form the LSC algorithm based on derived formulas were taken as the“evaluated value”.By comparing the differences between the“reference value”and the“evaluated value”of the gravity gradient,we found that:1)The“evaluated value”obtained by the LSC method is consistent in spatial pattern of variation with the“reference value”derived from the spectral domain method.The vertical component of the gravity gradient disturbance describes the boundary characteristics of the field source more precisely than the vertical component of the gravity anomaly,and other gravity gradient disturbance components provide the information r

关 键 词：协方差函数 起伏地形 云南地区 非格网重力值 区域重力梯度场构建 

分 类 号：P315.726[天文地球—地震学]