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 Decemher 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 intefferometry (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-Bain 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.
引文
Bergman R,Rosen PA,Fielding EJ.2000. Synthetic Aperture Radar interferometry to measure earth's surface topography and its deformation.Annu.Rev.Earth Planet.Sci.,28:169-209
Gabriel AK,Goldstein RM.1988. Crossed orbit interferometry-theory and experimental results from SIR-B.Int.J.Remote Sens,9:857-872
Goldstein RM,Engelhardt H,Kamb B,Frolich RM.1993. Satellite radar interferometry for monitoring ice sheet motion-application to an Antarctic ice stream.Science,262:1525-1530
Hassen RF.2001. Radar interferometry-data interpretation and error analysis.Kluwer Academic Publishers
ICG Reconnaissance Mission.2004. Bam earthquake of 26 December 2003
Massonnet D,Rossi M,Carmona C,Adragna F,Peltzer G,Feigl K & Rabaute T.1993. The displacement field of the Landers earthquake mapped by radar interferometry.Nature,364:138-142
Nakamura T,Suzuki S,Sadeghi H,Aghda SMF,Matsushlima T,Ito Y,Hosseini SK,Gandomi AJ & Maleki M.2005. Source fault structure of the 2003 Bam earthquake,southeastern Iran,inferred from the aftershock distribution and its relation to the heavily damaged area:Existence of the Arg-e-Bam fault proposed.Geophys.Res.Let.,32:L09308,doi:10. 1029/2005GL022631
Okada Y.1985. Surface deformation due to shear and tensile faults in a half-space.Bull.Seism.Soc.Am.,75:1135-ll54
Talebian M et al.2004. The 2003 Bam(Iran)earthquake:rupture of a blind strike-slip fault.Geophys.Res.Let.,31:doi:10. 1029/2004GL020058
Tatar M,Javan D,Farabhod A,Paul A & Hatzfeld D.2004. Aftershock seismicity of the Bam earthquake,European Geosciences Union-1~(st)General Assembly(Abstract EGU-A-07893) ,Nice,France,25-30 April,2004
Wright JT,Parsons EB,Lu Z.2004. Toward mapping surface deformation in three dimension using INSAR.Geophs.Res.Let.,31:L01617
Yagi Y.2004. Preliminary Results of Rupture Process for 2003 December 26 Southeastern IRAN,Earthquake,IISEE
wwv.iiees,ac.ir
www.ngdir.ir
www.gsi.org.ir
廖明生,林珲.2003. 雷达干涉测量.北京:测绘出版社
凌勇.2005. 基于 D-InSAR 的巴姆 Mw6. 6地震变形场研究.北京大学硕士学位论文
王超,张红,刘智.2002. 星载合成孔径雷达干涉测量.北京:科学出版社
曾琪明.2001. 合成孔径雷达干涉技术研究与应用.北京大学博士学位论文