【作者】 郑建中； 徐文跃； 刘进； 邹英；

【Author】 Zheng Jianzhong Xu Wenyue Liu Jin Zou Ying (Institute of Geophysics,Chinese Academy of Sciences)

【机构】 中国科学院地球物理研究所；

【摘要】 本文对攀-西裂谷带的地震平面分布、震源深度分布、地震随时间的分布、b值、断层滑动率和应力场进行了研究,其结果是:(1)4.7级以上的地震主要发生在攀-西裂谷带的主断层上,攀-西裂谷两侧的地震活动性高于裂谷轴部,6级以上地震主要沿攀-西裂谷带的边界断层发生,较小地震则随机分布;(2)攀-西裂谷轴部的震源深度较浅(5—20 km),而裂谷两侧地区的震源深度较深(6—40km);(3)攀-西裂谷带的b值为0.58—0.75;(4)攀-西裂谷带与印度-欧亚碰撞带的地震活动相关性极为密切;(5)攀-西裂谷带的断层面近于直立,而且是走滑型的,断层滑动率为0.13—0.19cm/a;(6)攀-西裂谷带的最大主压应力轴近于水平,其方向为北北西-南南东.本文根据上述结果提出了攀-西裂谷消亡过程的地球动力学模式.更多还原

【Abstract】 Some characteristics of the distribution of the earthquake epicenters and the focus depth time-dependence of the earthquake occurences,b-values,fault slip rates and stress field in the Pan-Xi rift zone have been investigated.The results are as follows:(1) Earthquakes with≥4.7 occurred mainly along the major faults in the Pan-Xi rift zone.Earthquake activity in the both sides of the Pan-Xi rift zone is greater than that along its axis.Earthquakes with M≥6 oc curred along the bounding faults of the Pan-Xi rift zone.The small earthquakes exhibit a ran dom distribution.(2) The focal depths along the axis of the Pan-Xi rift zone are shallow (5-20km),but the focal depths outside the rift zone are deeper(6-40 km)(3) The b-values in the Pan-Xi rift zone are 0.58-0.75.(4) The correlation of the seismicity between the Pan-Xi rift zone and the eastern India-Eurasian collision zone is high.(5) The fault planes in the Pan-Xi rift zone are nearly vertical and strike-slip.The fault slip rates in the Pan-Xi rift zone are 0.13-0.19 cm/a.(6) The maximum principal compressive stress axis in the Pan-Xi rift zone is nearly horizontal,NNW-SSE in direction. Based on the above results,a dynamic model for the aborting process of the Pan-Xi rift zone is suggested.更多还原