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以向错理论为基础,利用经典点源位错理论的解析式,推导得出了断层三维滑动和转动引起的空间重力变化.计算并分析了简单断层三维转动引起的空间重力变化特征,并基于子断层叠加法,采用数值方法模拟计算了智利大震同震断层转动引起的空间重力变化,将计算结果与断层滑动模拟的结果进行了对比.结果表明:断层单分量转动ω_1产生的空间重力变化分布区域具有明显的不对称性,单分量转动ω_2、ω_3时均呈现沿断层倾向方向为轴的对称分布特征;当断层同时以ω_1ω_2转动时,ω_1的转动效应将打破整个重力变化分布区域的的空间对称性.当断层同时以ω_2ω_3转动时,ω_2的转动效应对转动结果起主导作用;断层转动和断层滑动在计算大震同震引起的空间重力变化时,计算结果具有相同的量级.相较于断层滑动,断层转动引起的重力变化在空间上呈显著的不均匀分布,重力变化分布区域相对更大.
Based on the error theory, the spatial gravity change caused by the three-dimensional sliding and rotation of the fault is deduced by using the analytic formula of the classical point source dislocation theory. The spatial gravity change caused by the three-dimensional rotation of the simple fault is calculated and analyzed. Sub-fault superposition method, the space gravity change caused by the coseismic fault rotation in Chile earthquake is simulated by numerical method, and the calculated results are compared with the results of fault slip simulation.The results show that the space gravity changes caused by the single component rotation ω_1 The distribution region has obvious asymmetry. When the single component turns ω_2 and ω_3, they both show the symmetrical distribution along the direction of fault orientation. When the fault rotates at the same time ω_1ω_2, the rotation effect of ω_1 will break the whole gravity distribution Space symmetry.When the fault rotates with ω_2ω_3 at the same time, the rotation effect of ω_2 plays a dominant role in the rotation results. The fault rotation and fault slip have the same order of magnitude when calculating the spatial gravity changes due to the coseismicity of large earthquakes. Compared with the fault slip, the gravity change caused by the fault rotation is significantly unevenly distributed in space, and the weight Changes in the distribution area is relatively larger.