文章基本信息

标题：Determination of Moho Discontinuity from Satellite Gradiometry Data: Linear Approach
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作者：Mehdi Eshagh
期刊名称：Geodynamics Research International Bulletin
电子版ISSN：2345-4997
出版年度：2014
卷号：1
期号：2
页码：14
语种：
出版社：geodynamics Research International Bulletin Online
摘要：The satellite gradiometry data (SGD) can be used for studying the crustal structure in addition to the Earth’s gravity field. This paper will show how this type of data is related to the Moho discontinuity or the boundary between the Earth’s crust and mantle. Here, the Vening Meinesz-Moritz (VMM) theory of isostasy is used and its mathematical formulae are modified to use the SGD instead of the Earth gravity models. A linear integral equation with a well-behaving kernel is presented by approximating the Moho depth formula derived based on the VMM theory. The error of this approximation is less than 300 m in Iran as the study area. Furthermore, this paper shows that the contribution of the higher degree harmonics than 215 is less than 1% with respect to the total signal of Moho undulations. This means that the use of SGD is meaningful as they sense the harmonics of the Earth’s gravity field to this degree. Two methods of one-step and two-step are proposed for Moho determination and applied in Iran. It is shown that to reduce the effect of spatial truncation error of the integral formulae of both methods the central area should be smaller by 6◦ than the inversion area. Numerical studies show that the two-step approach is superior to the other one and the root mean squared error of differences between the Moho model recovered by an Earth gravity model and SGD is about 1.5 km in Iran.