巴姆地震变形场和应力场:Ⅰ.用差分干涉雷达和Okada方法求解  

Deformation and stress field of Bam earthquake:Ⅰ.InSar and Okada calculation.Acta Petrologica Sinica

作　　者：凌勇[1] 曾祺明[1] 罗扬[1] 赵永红[1] 

机构地区：[1]北京大学地球与空间科学学院,北京100871

出　　处：《岩石学报》2006年第9期2367-2374,共8页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(40234042)资助.

摘　　要：本文对2003年12月26日伊朗东南部克尔曼省巴姆地区发生的6.6级地震产生的位移场、应变场和应力降分布进行了定量研究。首先从差分干涉雷达(D～InSAR)出发,求解出此次地震的同震干涉条纹和雷达视线方向的位移场,并从雷达干涉的相干图上清楚的观察到了发震断层的痕迹,得出此次地震的发震断层是巴姆断层以西的隐伏断层的结论。然后结合 Harvard 的 CMT(震源机制解)结果、Nakamura 的断层结果(Arg-e-Bam 隐伏断层)以及本文 D-InSAR 求解出的发震断层结果,利用 Okada 程序,计算出此次地震的北、东、垂向三个位移分量,投影得到雷达视线方向的位移,将投影结果与由 D-InSAR得到的位移场比较,看到我们所讨论的断层模式可以很好的解释差分干涉雷达的观测结果,可以合理的解释 Arg-e-Bam 隐伏断层为此次地震的发震破裂断层,通过分析地震的破坏程度分布图,隐伏断层为发震断层的解释可以很好的符合巴姆地震的等震分布图。最后,本文利用 Okada 程序计算得到了此次地震所产生的应变场和应力降场。The quantitative calculation of the displacement, deformation and stress fields of Bam Mw6.6 earthquake which occurred in the southeastern part of Iran at 1：56 UTC （5：26 in local time） on December 26, 2003 were carried out in this study. The coherence images and the surface displacement in LOS direction were derived using differential synthetic aperture radar interferometry （D-InSAR） method. The location of the source fault was determined in the coherence images. The northern, eastern, and vertical displacement components simulated from Arg-e-Bam rupture were calculated using Okada＇s program. All three displacement components were projected to the LOS direction, and compared to the results from D-InSAR. The conclusion could be made that the Arg-e-Bam fault is the source rupture fault. The strain and stress fields induced by the earthquake were also calculated using Okada＇s program.

关 键 词：巴姆地震 雷达差分干涉 发震断层 位移场 应变场 应力降 

分 类 号：P315.63[天文地球—地震学]