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对强震发生后周围断层及未来强震形势的影响研究具有非常重要的意义.青藏高原东北缘强震频发,对该区的历史强震进行研究很有必要.以青藏高原东北缘及邻区为目标建立3D黏弹性有限元模型,依据中国大陆Ⅰ级块体和青藏高原Ⅱ级块体划分及活动断裂分布确定模型块体边界及断裂位置,使用GPS观测资料作为模型边界条件,数值模拟1900年以来7级以上强震发生的动力学过程.计算结果表明:1青藏高原东北缘及邻区区域水平构造应力场特征大致呈从西向东,从南向北减小分布.2模拟结果说明强震主要发生在背景场应力和强震引起的等效应力加载的断层上.3历史强震序列对1970年以来地震的影响:康定地震加速触发了炉霍地震的发生;康定、炉霍地震对松潘地震无加速触发作用;康定、炉霍、松潘地震对共和地震无加速触发作用;炉霍、松潘、共和地震对汶川地震的影响较小;汶川地震延缓了芦山地震的发生.
It is very important to study the influence of the surrounding faults and the future strong earthquakes after the strong earthquakes.The strong earthquakes on the northeastern margin of the Qinghai-Tibet Plateau are very frequent and it is necessary to study the historical strong earthquakes in this area.Based on the northeast margin of the Qinghai- 3D viscoelastic finite element model was established. According to the division of level I block in the Chinese mainland and the distribution of active faults in the Qinghai-Tibetan Plateau, the boundary and the fracture location of the model block were determined. GPS observation data were used as the model boundary conditions and the numerical simulation The results show that: 1 The horizontal tectonic stress field in the northeastern margin of the Qinghai-Tibet Plateau and its adjacent areas roughly distributes from west to east and decreases from south to north.2 Simulation results show that The strong earthquakes mainly occurred on the faults loaded by the background stress and the equivalent stress caused by the strong earthquakes.3 The influence of the strong earthquake sequence on the earthquakes since 1970: The acceleration of the earthquakes triggered by the Kangding earthquake accelerated the occurrence of the earthquakes; No accelerating trigger on the Songpan earthquake; the Kangding, Luhuo and Songpan earthquakes did not trigger the acceleration of the Gonghe earthquake; the influence of the Luhuo, Songpan and Gonghe earthquakes on the Wenchuan earthquake Smaller; Lushan earthquake delayed the occurrence of the earthquake.