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基于位错理论,考虑重力和黏弹性的影响,在分层介质模型下计算鲁甸地震引起的同震、震后形变和重力变化.结果表明形变和重力的显著变化主要发生于断层在地表投影附近区域.同震形变场显示发震断层有明显的走滑性质.考虑黏弹松弛效应,随着时间的推移,震后形变和重力有了明显改变,同震效应为正的区域得到加强,为负区域进一步减弱.震后松弛效应的影响范围相比同震明显增加.在靠近断层的GPS观测台站处,计算了由黏弹松弛效应引起的震后形变和重力时间序列.震后松弛效应引起的重力变化在50年之后均达到同震水平,除了NJ13的纬向、垂直位移,NJ16的垂直位移,NJ15的径向位移,其余台站的所有震后形变都超过1mm.观测台站的震后重力和垂直位移时间序列在震后100年趋于稳定,纬向位移和经向位移在震后50年趋于稳定.
Based on the dislocation theory and considering the influence of gravity and viscoelasticity, the coseismic, post-earthquake deformation and gravity changes caused by the Ludian earthquake are calculated under the stratified medium model. The results show that the significant changes of deformation and gravity mainly occur in the surface projection The co-seismic deformation field shows obvious strike-slip properties of the seismogenic fault.According to the viscoelastic relaxation effect, with the passage of time, the post-earthquake deformation and gravity have obviously changed, and the area with positive co-seismic effect has been strengthened, The negative area further weakened.After the earthquake the relaxation effect of the scope of the impact is significantly increased compared with the coseismic.The GPS observation station near the fault, calculated by the viscoelastic relaxation effect after the post-earthquake deformation and gravity time series.After relaxation The gravity-induced changes in gravity all reach the level of coseismic shock after 50 years, except for the latitudinal and vertical displacements of NJ13, the vertical displacements of NJ16 and the radial displacements of NJ15, and all post-earthquake deformations of the remaining stations exceed 1 mm. After the earthquake, the time series of gravity and vertical displacement tended to be stable, and the latitudinal and meridional displacements tended to be stable in the 50 years after the earthquake.