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2006年12月26日发生了屏东Mw7.0级强烈地震,之后Harvard,USGS和中国台湾的BATS分别对其进行了定位.不同来源的震源机制研究结果均认为该地震属于正断层地震,但震源深度定位差别很大.多数学者都支持本次地震震源深度为40～44km之间.为进一步探讨本次地震的地球动力学成因,根据上述结果,在详细计算相关参数后进行了二维有限元数值实验分析.结果表明屏东地震发生的主要动力学背景与成因为:由于弧-陆碰撞的作用使得台湾地区地壳部分整体处于北西-南东向压应力状态,但由于柔性下地壳的存在,使得上地壳变形与岩石圈地幔变形解耦,岩石圈地幔板片在弯曲俯冲的过程中,会在其上表面处于拉张状态从而形成正断层机制的地震.
The strong Mw7.0 earthquake occurred in Pingtung on December 26, 2006. After that, Harvard, USGS and BATS in Taiwan of China separately located them.The results from different source mechanisms suggest that the earthquake is a normal fault, Most of the scholars support the focal depth of this earthquake is between 40 ~ 44km. In order to further investigate the geodynamic cause of this earthquake, based on the above results, after a detailed calculation of the relevant parameters, a two-dimensional finite The results show that the main dynamical background and causes of the Pingtung earthquake are that the whole crust in Taiwan is in the NW-NS compressive stress due to the arc-continent collision, but due to the existence of the soft lower crust So that deformation of the upper crust is decoupled from lithospheric mantle deformation. In the process of bending subduction, the lithospheric mantle veneer will be tensioned on its upper surface to form a normal fault mechanism earthquake.