利用协同反演方法反演地震序列滑动分布

在利用大地测量数据对地震序列进行滑动分布反演中,由于地震序列中多次地震的发震间隔短、InSAR数据时间跨度大,包含了多次地震产生的形变,难以利用InSAR数据反演单次地震的滑动分布,故本文利用协同反演方法结合GPS数据分离地震序列中单次地震产生的InSAR形变,从而反演单次地震的滑动分布.为验证本文方法的有效性,分别采...

A cooperation inverse approach to invert the slip distribution of earthquake sequence

In the using the geodetic data to invert the slip distribution of seismic sequences, due to the short recurrence interval of multiple earthquakes in the earthquake sequence, and multiple deformations from the earthquake included in the InSAR data with large time span. Therefore, it is difficult to use the InSAR data to invert slip distribution of an earthquake. To deal with the issue, a cooperative inversion method to invert the slip distribution of an earthquake in a seismic sequence is proposed. Furthermore, the suitability of the joint inversion method and the proposed method are respectively validated with the simulated tests, and the variance component estimation method is used to determine relative weight ratio. The simulated experiment results show that the proposed method can effectively invert the slip distribution of an earthquake sequence, and the proposed method need not determine relative weight ratio. Naturally, we also invert the slip distribution of MW6.4 foreshock and MW7.1 main shock of the Ridgecrest earthquake using the proposed method. The real experiments results demonstrate that the MW7.1 main shock is a right-lateral strike-slip fault in the northwest direction, and the MW6.4 foreshock consists of right-lateral strike-slip fault in northwest direction and left-lateral strike-slip fault in northeast direction. The maximum slips for both earthquakes are 4.26m and 1.0m, respectively, and the cumulative releasing seismic moments are 4.49×1019N·m and 5.28×1018N·m with the corresponding moment magnitudes of MW7.07 and MW6.45, respectively. Interestingly, the experimental results are identical to that of the existing investigations. The results of the simulation experiment and the Ridgecrest seismic sequence inversion in California show that the proposed method can successfully use the GPS data and InSAR data with multiple seismic deformations to invest the slip distribution of an earthquake, and the proposed method need not determine relative weight ratio. Due to different kinds of data are used in cooperation as prior information, so the results inverted by using low accuracy data will be worse. However, joint inversion can reduce the influence through posed different relative weight ratio factor in data with low accuracy.