摘要
地震位错理论是解释地震形变,并进行反演估算地震破裂模型的理论基础.当前的地震位错理论基于地球模型主要分为:均匀半无限模型、层状半无限模型、均质球形模型和层状球形模型.本文利用基于不同地球模型的位错理论,针对不同深度的地震,分析了同震水平、垂直形变的分布特征,讨论了导致同震形变差异的主要因素,即地球层状结构和曲率对同震形变结果产生的影响,以此探讨基于不同地球模型的位错理论的适用性.通过对比均匀半无限和层状半无限模型、均质球形和层状球形模型下的同震形变结果,发现形变量在近场的差异要大于在远场的差异,即地球层状结构在近场有较大的影响,其中对最大水平形变的影响可达到37%;通过对比均匀半无限和均质球形模型、层状半无限和层状球形模型下的同震形变结果,当震源深度较深时,形变量在远场的差异大于在近场的差异,即地球曲率在远场的影响大于在近场的影响,并且其明显小于地球的层状结构的影响.
Dislocation theory plays an important role in calculating coseismic deformation and inverting seismic fault models. Depending on different earth models,there are four main dislocation models：homogeneous half-space, heterogeneous half-space, homogeneous sphere and heterogeneous sphere. These different earth models are used in this study to calculate the effect of earth ＇s radial heterogeneity and earth＇s spherical curvature in both near field and far field. Comparing homogeneous and heterogeneous half-space models,homogeneous and heterogeneous sphere models,we find earth＇s radial heterogeneity effect is more obvious in near field than that in far field,and it can cause up to 37 per cent errors for the maximum horizontal deformation. Comparing homogeneous halfspace and sphere models, heterogeneous half-space and sphere models,when source depth is large,earth＇s curvature effect in far field is more obvious,indicating that earth＇s stratification effect is much more larger than earth＇s sphericity effect.
出处
《地球物理学进展》
CSCD
北大核心
2016年第2期597-605,共9页
Progress in Geophysics
基金
东北亚地震
海啸和火山合作研究计划项目(ZRH2014-01-02)
国家自然科学基金项目(41574071)
地震行业科研专项(201108004)联合资助
关键词
地震位错理论
地球模型
同震形变
地球层状结构
地球曲率
dislocation theory
earth model
coseismic deformation
earth＇s layered structure
earth＇s sphericity
