Fault activity characteristics in the northern margin of the Tibetan Plateau before the Menyuan Ms6.4 earthquake

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• 作者：Dongzhuo Xu^a ; ^{donglicf@163.com" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Chuanbao Zhu^b ; Xiangang Meng^a ; Yuan Li^a ; Qikai Sun^a ; Ke Zhang^a
• 关键词：Northern margin of the Tibet plateau ; Fault belt ; Cross-fault observation data ; Deformation analysis
• 刊名：Geodesy and Geodynamics
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：7
• 期：4
• 页码：261-267
• 全文大小：1541 K

文摘

Fault deformation characteristics in the northern margin of the Tibetan Plateau before the Menyuan Ms6.4 earthquake are investigated through time-series and structural geological analysis based on cross-fault observation data from the Qilian Mountain–Haiyuan Fault belt and the West Qinling Fault belt. The results indicate: 1) Group short-term abnormal variations appeared in the Qilian Mountain–Haiyuan Fault belt and the West Qinling Fault belt before the Menyuan Ms6.4 earthquake. 2) More medium and short-term anomalies appear in the middle-eastern segment of the Qilian Mountain Fault belt and the West Qinling Fault belt, suggesting that the faults' activities are strong in these areas. The faults' activities in the middle-eastern segment of the Qilian Fault belt result from extensional stress, as before the earthquake, whereas those in the West Qinling Fault belt are mainly compressional. 3) In recent years, moderate-strong earthquakes occurred in both the Kunlun Mountain and the Qilian Mountain Fault belts, and some energy was released. It is possible that the seismicity moved eastward under this regime. Therefore, we should pay attention to the West Qinling Mountain area where an Ms6–7 earthquake could occur in future.