On the use of the geoid anomalies for geophysical interpretation over the area of Hunan
On the use of the geoid anomalies for geophysical interpretation over the area of Hunan
复制标题
大地水准面异常在湖南地区地球物理解释中的应用
DOI：
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复制
发表时间：
2012
影响因子：
1.4
通讯作者：
LIN Miao1,2,ZHU Jian-Jun1,2,TIAN Yu-Miao1,2,TAO Xi
中科院分区：
文献类型：
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作者：
林淼;朱建军;田玉淼;陶肖静;LIN Miao1,2,ZHU Jian-Jun1,2,TIAN Yu-Miao1,2,TAO Xi
本文研究了大地水准面异常在地球物理解释中的应用，利用超高位模型EGM 2008计算重力大地水准面，相应的布格大地水准面和均衡大地水准面是由完整的地形和艾里-本文首先采用棱柱体法和镶嵌面法相结合的综合方法对大地水准面进行Heiskanen局部均衡改正，然后将大地水准面分解为反映异常特征的残差最后，以湖南地区为例，利用剩余重力大地水准面和其它地球物理资料，研究了不同深度的重力大地水准面，结果表明，剩余重力大地水准面能有效地揭示深部裂谷的分布、构造块体的位置和上地幔密度的横向分布等异常结构。但地壳异常特征不明显，岩石圈密度异常变化较浅部平缓，厚度由东向西逐渐变厚，莫霍面起伏和研究区地壳均衡状态可作为补充信息。通过对剩余均衡大地水准面和Airy局部均衡莫霍面深度的分析，初步推断出了地球物理解释中重力异常的分布规律，为解决边远地区重力资料缺乏和稀少的问题提供了一条新的途径。
In this paper,we investigated the applications of geoid anomalies in geophysical interpretation.The ultra-high geopotential model EGM2008 is used to compute the gravimetric geoid,and the corresponding Bouguer and isostatic geoids are obtained from complete topographic and Airy-Heiskanen local isostatic corrections with a synthetic method combining the prism and tesseroid approaches.Then the geoids are divided into several residuals which represent anomalous features in different depths,by removing different wavelength components.Finally,a case study over the Hunan area based on these data sets and other geophysical data is presented.The results show that the residual gravimetric geoids can reveal some anomalous structures in deep earth effectively,such as the distributions of deep rifts,the locations of tectonic blocks and the lateral density distribution in the upper mantle etc..However,the anomalous features in the crust are not evident in these residuals.The variation of density anomalies in the lithosphere is much smoother than that in the shallower depth,while the thickness of the lithosphere deepens from east to west.The Moho undulations,and the isostatic state of the research area which can be regarded as complementary information,are inferred roughly from the analysis of both the residual isostatic geoids and Airy local isostatic Moho depths.The results showed above give us a new way to overcome the absence and sparseness of gravity data in remote areas for geophysical interpretation.