重力异常频谱分析方法研究与应用  

Gravity Anomaly Spectrum Analysis Method and Its Application

作　　者：何慧优 方剑 HE Huiyou;FANG Jian(State Key Laboratory of Geodesy and Earth's Dynamics,Wuhan 430077,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]大地测量与地球动力学国家重点实验室,湖北武汉430077 [2]中国科学院大学,北京100049

出　　处：《武汉大学学报（信息科学版）》2023年第12期2092-2102,共11页Geomatics and Information Science of Wuhan University

基　　金：国家重点研发计划(2016YFC0601101);国家自然科学基金(41874091,41874096);中国科学院战略性先导科技专项(XDB18010304);大地测量与地球动力学国家重点实验自主项目(S21L6401)。

摘　　要：频谱分析是以波数为自变量对位场异常频谱进行分析研究,从而解决实际工作中的异常转换、滤波、正反演等问题。位场的频谱特征包含了地下地层的空间分布、岩性及构造特征,有助于地球物理资料的解释、分析,为进一步了解研究区域概况提供信息。位场异常谱中的振幅谱与地下地质体的埋深、宽度与物性都有直接的关系;相位谱则反映了地下地质体的水平位置与倾角信息。计算了多种类型模型的频谱曲线,分析频谱曲线特征,并详细说明了模型参数变化对频谱曲线的影响;阐述了振幅谱反演、相位谱反演方法,提出了频率域联合反演方法,精确地反演模型的几何参数。将此方法应用于武清凹陷地层分析,反演得到了两个观测剖面的目标层深度和宽度,与实测地震资料对比,表现出较好的反演结果。Objectives:Spectral analysis is to analyze and study various spectra of potential anomalies with wave-number as the independent variable,to solve the problems of anomaly conversion,filtering and forward and inverse analysis in practical work.The spectral characteristics of the potential,which include the spatial distribution,lithology and tectonic characteristics of the subsurface stratum,help the interpretation and analysis of geophysical data and provide information for further understanding of the study area.The amplitude spectrum of the potential anomaly spectrum is directly related to the burial depth,width of the subsurface geological body;the phase spectrum reflects the information of the horizontal position and dip angle of the subsurface geological body.However,in previous studies,most of the researchers’work had been focused on making use of the characteristics of fast calculation of the bitfield data in the frequency domain,doing a lot of forward work as well as applying the relationship between the spectrum and the parameters of the geologic body for inversion,but the analysis of the spectral characteristics of different geologic bodies and the specific effects of the geologic body parameters on the spectrum have been less studied.On the other hand,there are few studies on the joint inversion using different spectra in the frequency domain inversion.Methods:In order to better carry out the study of gravity anomaly in the frequency domain,using the characteristics of simple,solvable and easy to program and fast computation of the expression for the positive inversion of gravity anomaly in the frequency domain,the spectral curves of various models are calculated,and the characteristics of the spectral curves,and detailed effects of model parameter changes on the spectral curves are analyzed too.It also includes how to interpret the amplitude spectral inversion and phase spectral inversion,and proposes a joint inversion method in the frequency domain to accurately invert the geometric parameters of the

关 键 词：重力异常 频谱分析 频率域正反演 振幅谱反演 

分 类 号：P223[天文地球—大地测量学与测量工程]