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应用一种非线性加权最小二乘反演方法,对一个位于半空间为粘弹性介质且具有平移断裂作用之上的人工弹性层模型进行反演,得到了弹性层的应变速率,并用于追踪加利福尼亚的圣安德烈斯大断裂某些地段的地震活动.该模型的各项参数是:弹性层的厚度(δ);断层的深度(d);地震再出现的时间(t);弹性层和粘弹性半空间的平均剪切模量(G);半空间的粘滞度(η);同震偏移(DU).只有粘滞度与剪切模量的比可以求得,而且剪切模量保持不变.根据综合资料的特征向量分析方法,利用非常靠近断裂的最后一次地震以来只随时间变化的观测结果,来求得剩下的五个参数是不可能的.我们对圣安德烈斯大断裂进行了一系列反演计算,每一次反演都用固定的重复出现时间和固定深度这些特征值.这些反演结果与以前的资料有点不吻合。得到的是剩余三个参数的一系列估计值,而不是特定值.根据取自圣安德烈斯大断裂北部资料的反演结果来看,出现了所预料的参数范围,该参数范围与用整个断裂资料反演得到的结果类似。随着到断层距离不同而变化的辅助观测值将有助于约束这些范围,并且有可能得出地震再次出现的时间和震源深度的解。
A nonlinear weighted least square inversion method was applied to inverse a model of artificial elastic layer located in a half-space with viscoelastic medium and having translational fracture. The strain rate of the elastic layer was obtained and used to track the deformation of California Seismic activities in some areas of the Great San Andreas Fault, the parameters of this model are: thickness of elastic layer (δ); depth of fault (d); reappearance time (t) of elastic layer and Viscoelastic half-space average shear modulus (G); half-space viscosity (η); coseismic migration (DU). Only the ratio of viscosity to shear modulus can be obtained, Modulus remains unchanged.According to the method of eigenvector analysis based on the comprehensive data, it is impossible to obtain the remaining five parameters by observing only the time-dependent observations since the last earthquake very close to the fault. A series of inversion calculations were carried out for the Great Creusian Fault, with a fixed recurrence time and fixed depth for each inversion. These inversion results are somewhat inconsistent with the previous data. A series of estimates of the remaining three parameters are obtained, rather than a specific value, and based on the inversion of the data taken from the northern part of the San Andrés Great Fault, the expected range of parameters appears, The whole fault data inversion results are similar. Auxiliary observations that change as the distance to the fault varies will help to constrain these ranges and it is possible to arrive at a solution to the time and source depth of the earthquake.