广西河池地区的地震活动及发震机制的岩石实验解释

A INTERPRETATION ON THE SEISMICITY AND MECHANISM OF EARTHQUAKE OCCURRED IN HECHI REGION, GUANGXI USING THE RESULTS OF ROCK EXPERIMENT

摘要:

本文讨论了广西河池地区地震活动的时空分布、应力场“窗口”效应和小震级高烈度等特征,並利用岩石实验的某些结果对该区地震的发震机制作了一些定性解释。该区是一个两组断裂交汇的应力敏感区,地震是在低应力条件下在极不均匀介质宁原有裂隙发生粘滑的结果,其特殊的地体环境下可能构成蕴育大震的条件,其地震活动不会对邻近的龙滩库坝区造成威胁。

Abstract:

In this paper, we have discussed the temporal-spatial distribution of seismicity, "window effect" of stress field and the feature for small in magnitude but high in intensity in Hechi region, Guangxi. A qualitative interpretation for the mechanism of earthquakes occurred in this region has been done using some results of rock experiment.
The region is situated in two intersecting faults and it is sensitive to stress. The research result shows that the seismicity attributed to stick slip of existing fracture under low stress in very inhomogeneous medium. Special geological setting can not compose a condition preparating great earthquakes and the seismicity can not constitute a threat to Longtan reservior region nearby.