1970年通海Ms7.7地震后青藏高原东南部小江断裂带和红河断裂带的库仑应力变化研究

基于1970年通海MS7.7地震的破裂参数，利用模型对不同岩石圈流变特性下库仑破裂应力的变化进行研究，探讨通海地震的静态同震变形和短期震后变形对小江断裂带和红河断裂带上潜在地震活动的影响。结果表明，这2条断裂带的一些断裂段在深度7.5 km处库仑破裂应力增量(ΔCFS)的震时变化达到0.12~0.50 bar，48 a后由于下地壳和上地幔的应力松弛，相同位置的库仑破裂应力增量高达0.22~0.90 bar。说明1970年通海MS7.7地震增强了小江断裂带和红河断裂带上潜在的地震活动性，在将来的地震工作中应加强对其的研究，并通过增加野外观测的方式监测其地震活动与地壳运动模式。

Coulomb Stress Change on the Xiaojiang and the Red River Faults,Southeastern Tibetan Plateau,from the 1970 Tonghai MS7.7 Earthquake

Based on previous studies, the rupture parameters of the 1970 Tonghai MS7.7 earthquake are obtained. Using the model, we study the changes of Coulomb rupture stress under different lithospheric rheological properties. We discuss the effects of static co-seismic deformation and short-term post-earthquake deformation on potential seismic activity in the Xiaojiang fault and the Red River fault. Results show that on some segments of the two faults, the coseismic change of Coulomb failure stress(ΔCFS) attains 0.12-0.50 bar at 7.5 km depth. Relaxation of the lower crust and the upper mantle adds the postseismic ΔCFS on the two faults up to 0.22-0.90 bar after 48 years. This means that the 1970 event is increasing the potential of seismic activity along the two active faults. In this case, we should pay more attention to these two active faults in future research by increasing field observations to monitor the seismic activity and the crustal motion pattern.