王永哲. 2015: 利用GPS和InSAR数据反演2011年日本东北MW9.0地震断层的同震滑动分布. 地震学报, 37(5): 796-805. DOI: 10.11939/jass.2015.05.008
引用本文: 王永哲. 2015: 利用GPS和InSAR数据反演2011年日本东北MW9.0地震断层的同震滑动分布. 地震学报, 37(5): 796-805. DOI: 10.11939/jass.2015.05.008
Wang Yongzhe. 2015: Coseismic slip distribution of the 2011 Tohoku MW9.0 earthquake inferred from GPS and InSAR data. Acta Seismologica Sinica, 37(5): 796-805. DOI: 10.11939/jass.2015.05.008
Citation: Wang Yongzhe. 2015: Coseismic slip distribution of the 2011 Tohoku MW9.0 earthquake inferred from GPS and InSAR data. Acta Seismologica Sinica, 37(5): 796-805. DOI: 10.11939/jass.2015.05.008

利用GPS和InSAR数据反演2011年日本东北MW9.0地震断层的同震滑动分布

Coseismic slip distribution of the 2011 Tohoku MW9.0 earthquake inferred from GPS and InSAR data

  • 摘要: 本文首先对Envisat/ASAR数据进行干涉处理, 获取2011年日本东北MW9.0地震的地表InSAR同震形变场; 然后通过对InSAR同震形变数据重采样方法的深入分析, 选择条纹率法结合干涉图的空间相干性对InSAR同震形变数据进行重采样; 最后基于弹性半空间位错模型, 联合InSAR与GPS形变数据, 采用最小二乘法反演发震断层的滑动分布. 研究结果表明: 考虑相干性的条纹率重采样方法, 更适用于形变场中存在除断层外的有限边界、 且形变场范围较大的InSAR数据重采样处理; 断层滑动主要发生在地表以下50 km范围内, 最大滑动量为49.9 m, 矩张量为4.89×1022 N·m, 所对应的矩震级为MW9.1, 与地震学反演的结果比较吻合.

     

    Abstract: To determine the causative fault slip distribution of the Tohoku MW9.0 earthquake in Japan, the coseismic deformation field of this earthquake was obtained with synthetic aperture radar interferometry (InSAR) technique based on Envisat/ASAR data. With detailed analysis and comparison of different methods used to resample InSAR deformation data, the fringe rate method taking into account spatial coherence of the interferogram was chosen for data resampling. Based on the elastic half-space dislocation model, the slip distribution of causative fault was inverted from InSAR and GPS data using the least squares method. The research results show that the fringe rate with coherence method is more suitable for data resampling of wider range InSAR deformation field, within which there are finite boundaries except fault. The majority of the fault slips occurred mainly in the range of 50 km below the surface, and the maximal slip on the fault is 49.9 m, meanwhile, the moment tensor is 4.89×1022 N·m, the corresponding moment magnitude is MW9.1. All these are consistent well with the results from seismological inversion, suggesting this inversion result in this study is reliable.

     

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