太平洋板块俯冲对中国东北深浅震影响机理的数值模拟

Numerical Simulations of the Influencing Mechanism of the Pacific Plate Subduction to NE China on Deep and Shallow Earthquakes

本文采用与深度有关的不同分层结构模型,并考虑太平洋板块俯冲角度差异等特征,建立太平洋板块向中国东北地区俯冲的2D纵向静力学模型。以太平洋板片俯冲速度为约束条件,通过变化俯冲板块的俯冲角度,数值模拟太平洋板块向中国东北的俯冲过程,探讨太平洋板块俯冲作用对于我国东北深浅震的影响,得到不同俯冲角度模型的深浅部应力场分布,揭示区域构造应力场的总体特征和断裂带局部特性,并讨论了活动断裂带以及邻近区域对东北地区深浅部构造应力场的响应。结果表明,太平洋板块俯冲角度的变化对于中国东北地区深浅震的地震活动格局具有重要影响,断裂带构造环境是浅源地震孕育的基本条件。

Using depth-dependent layers and considering the subduction angle the Pacific plate to NE China, we build a vertical static 2D finite element model about the Pacific plate diving into NE China with subduction velocity of the Pacific plate. By altering subducting angle, we discuss numerically the possible subducting process and its effects on deep and shallow earthquake. The results of our models show the stress distribution of the whole research region including total characteristic feature and region characteristic, and the ac- tive faults and its adjacent areas response to the stress from deep region. Our research re- suits imply that the subduction angle of the Pacific plate and the environment around faults in the crust having great effects on deep and shallow earthquake activities.