Surface potential and gravity changes due to internal dislocations in a spherical earth—I. Theory for a point dislocation
Surface potential and gravity changes due to internal dislocations in a spherical earth—I. Theory for a point dislocation
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DOI：
10.1111/j.1365-246x.1993.tb06988.x
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发表时间：
1993-09
影响因子：
2.8
通讯作者：
Wenke Sun;S. Okubo
中科院分区：
文献类型：
--
作者：
Wenke Sun;S. Okubo
本文研究了球对称地球模型中位错引起的位和重力变化。定义位错Love数来描述点源引起的地球弹性变形。我们讨论了剪切位错和张性位错，它们可以由四个独立的分量表示：垂直走滑、垂直倾滑、水平面上的张性开口和垂直平面上的张性开口。一个均匀地球模型的结果同意得很好，至少在lo内，从平地理论的预测。远场结果表明，在10”范围内的差异不大于10%。在近场情况下，无论是球理论还是平地球理论都没有什么区别，而在全局情况下，采用球理论是合理的。我们继续计算与径向非均匀地球模型（模型1066A）。其结果与均匀球的结果基本相似。然而，在某些情况下，两者之间的差异变得很大。例如，重力变化的节点线的位置在两个模型之间有很大的不同。这表明垂直分层对变形场有很大的影响。
SUMMARY This paper studies the potential and gravity changes caused by dislocations in spherically symmetric earth models. We define dislocation Love numbers to describe the elastic deformation of the earth raised by point sources. We discuss the shear and tensile dislocations, which can be expressed by four independent components: a vertical strike-slip, a vertical dip-slip, a tensile opening on a horizontal plane, and a tensile opening on a vertical plane. The results for a homogeneous earth model agree very well, at least within lo, with those predicted from flat-earth theory. The far-field results indicate no larger than 10per cent difference within 10". It makes little difference whether we use the theory on a sphere or that for a flat earth in the near field, while it is reasonable to use the spherical theory for global calculation. We proceed to calculations with a radially heterogeneous earth model (Model 1066A). The results are as a whole similar to those for a homogeneous sphere. In some cases, however, the difference between the two becomes significant. For example, the locations of the nodal lines of the gravity change differ significantly between the two models. This indicates that the vertical layering can cause considerable effects on the deformation fields.