顾及地壳粘弹性结构的地震断层震后形变反演分析

Post-seismic Deformation Inversion of Seismic Fault Considering the Crustal Viscoelastic Structure

顾及地壳的粘弹性结构特征,建立了基于粘弹性地球模型的地震断层震后反演模型。利用遗传算法重点对走滑断层和逆断层两种主要地震断层进行了震后形变反演研究,并与球体均匀模型反演进行了比较。研究结果表明:遗传算法能在较大范围内搜索出发震断层的位错参数,反演的结果基本可靠;基于粘弹性地球模型特征建立的地震断层震后反演模型,可较好地反演不同类型的地震断层震源位错参数;如果出现模型参数不清楚的情况,需综合考虑衡量反演结果的准则,找寻其他方法来判断,仅以VTPV最小作为反演准则并不可靠。

Considering the spherical visco-elastic structure,the post-seismic deformation inversion mode had been constructed based on the visco-elastic earth model.We developed the inversion mode and inversion software package based on the post-seismic fault dislocation model considering the cruststratified structure.Using the genetic algorithm to invert the different fault dislocation parameters due to strike slip fault,dip slip fault respectively and comparing to the result inverted from the homogenous dislocation model,the result shows that the inversion algorithm used here could invert the dislocation parameters from the large region using the genetic algorithm and the inversion result is better to use.The inversion mode proposed here could better invert the seismic source parameters to different types fault.There is also a important find to suggest us that we could not use the minimum of VTPV as the only rule to judge the inversion result whether good or not when the model mode is not obvious.We should find other ways to make a supplement judge.