A generalized theory of the figure of the Earth: Formulae
A generalized theory of the figure of the Earth: Formulae
复制标题
地球形状的广义理论：公式
DOI：
10.1007/s00190-018-1159-6
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发表时间：
2018
影响因子：
4.4
通讯作者：
Mian Zhang
中科院分区：
文献类型：
--
作者：
Chengli Huang;Yu Liu;Chengjun Liu;Mian Zhang
传统上，在计算地球等势面时，通常将横向均匀的球基地球模型(如PREM模型)作为输入，然后计算结果为对称形状。然而，众所周知，地球内部物质和密度分布复杂，特别是在上地幔和地壳中，不能将其视为对称球体。最近，CRUST1.0结壳层模式问世，并得到了广泛的认可。但不对称地壳(地幔)对地球平衡图的影响不能用传统的理论来分析。本文首次提出了将地球面形推广到三阶精度的理论，并提出了求解复方程组的迭代计算策略。为了验证这一广义理论，用PREM模型对该广义理论进行了退化，并与传统理论进行了比较，结果表明该广义理论退化后的结果与传统理论非常一致。同时，CRUST1.0模型的地壳对地球内部等势面图形的影响(包括直接影响和间接影响)及其对全球动力学扁化的影响将作为该理论的应用在所附文件中介绍。
Traditionally a laterally homogeneous and spherical base Earth model (e.g., the PREM model) is considered as input when computing the Earth’s equipotential surfaces, which are then resulted to be in symmetric shape. However, the Earth, known with a complex distribution of interior material and density, especially in the upper mantle and the crust, cannot be treated as a symmetric sphere. Recently, a CRUST1.0 model of crust layer is published and well accepted. But the effect caused by the asymmetric crust (and mantle) on equilibrium figures of the Earth cannot be analyzed by the traditional theories. A generalized theory of the figure of the Earth to third-order precision is firstly proposed in this paper, as well as the iterative calculation strategy to solve the complex equation system. In order to validate this generalized theory, the degeneration of this generalized theory with the PREM model is made and is compared with traditional theories, and it is shown that the result of this generalized theory, after degeneration, is consistent very well with traditional theory. Meanwhile, the effect (including both the direct and indirect effects) of the crust layer, from the CRUST1.0 model, on the figures of equipotential surfaces of the Earth’s interior, as well as their effects on the global dynamics flattening, will be presented as an application of this theory in accompanying paper.