A new fault rupture scenario for the 2003 Mw 6.6 Bam earthquake, SE Iran: Insights from the high-resolution QuickBird imagery and field observations
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- 作者：Bihong Fu ; Xinglin Lei ; Khaled Hessami ; Yoshiki Ninomiya ; Takashi Azuma ; Hisao Kondo
- 关键词：Strike-slip faulting ; Surface rupture ; Synthetic shear ; Fault model ; QuickBird imagery ; Bam earthquake ; Iran
- 刊名：Journal of Geodynamics
- 出版年：2007
- 出版时间：October 2007
- 年：2007
- 卷：44
- 期：3-5
- 页码：160-172
- 全文大小：4378 K
文摘
The December 26, 2003 Mw 6.6 Bam earthquake is one of the most disastrous earthquakes in Iran. QuickBird panchromatic and multispectral satellite imagery with 61 cm and 2.4 m ground resolution, respectively provide new insights into the surface rupturing process associated with this earthquake. The results indicate that this earthquake produced a 2–5 km-wide surface rupture zone with a complex geometric pattern. A 10-km-long surface rupture zone developed along the pre-existing Bam fault trace. Two additional surface rupture zones, each 2–5 km long, are oblique to the pre-existing Bam fault in angles of 20–35°. An analysis of geometric and geomorphic features also shows that movement on the Bam fault is mainly right-lateral motion with some compressional component. This interpretation is consistent with field investigations, analysis of aftershocks as well as teleseismic inversion. Therefore, we suggest that the 2003 Bam earthquake occurred on the Bam fault, and that the surface ruptures oblique to the Bam fault are caused by secondary faulting such as synthetic shears (Reidel shears). Our fault model for the Bam earthquake provides a new tectonic scenario for explaining complex surface deformations associated with the Bam earthquake.