摘要
本文构建一种应用有限元开展特征地震数值模拟的新方法,并以龙门山断裂带中段的浅层构造和动力学机制为背景,研究了平行逆冲断层分布格局对区域地震活动性的影响.结果表明,从断层活动相互影响的角度看,包含3条平行逆断层的断裂带的整体地震活动性并不适用严格周期的特征地震模型,当断层间距在20km以下时,随着断层间距的缩短,对单条断层应用特征地震模型的适用性会逐渐降低.龙门山断裂带中段的模拟计算结果显示,后山断裂的地震活动相对独立,区域活动性和中央断裂的断层活动很可能不适用严格周期的特征地震模型.
This paper constructs a finite element analysis （FEA）method for the numerical simulation of characteristic earthquakes,based on the wide-accepted knowledge of the shallow crustal structure and dynamic boundary conditions at the middle part of the Longmenshan fault zone.The influence of parallel thrust faults on regional seismic activity is focused on and simulated with this FEA model.The results show that the characteristic earthquake model with strict re-currence interval is not suitable for the entire fault zone which contains three parallel faults.When the distance between the faults is less than 20 km,the applicability of the characteristic earthquake model to each single fault is attenu-ated with the distance between the faults decreasing.The results based on the distribution pattern of the profile in the middle of the Longmenshan fault zone reveal that seismic activity of the back range fault is relatively independent,and the characteristic earthquake model with strict recurrence interval is not suitable for the entire fault zone and the central fault.
出处
《地震学报》
CSCD
北大核心
2014年第6期1010-1021,共12页
Acta Seismologica Sinica
基金
国家自然科学基金项目(41274101
40974022)资助
