发震构造呈复杂空间关系下相互影响发震的机理研究——以汶川地震为例  

Research on the Effect of Seismogenic Structure with Complex Spatial Relationship on Earthquake Mechanism with the Wenchuan Earthquake as An Example

作　　者：郭安宁[1] 郭增建[1] 张津[1] 赵乘程[1] 张炜超[1] 

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000

出　　处：《地震工程学报》2013年第1期196-202,共7页China Earthquake Engineering Journal

基　　金：国家科技部公益专项(8-44);科技部公益专项(201208001)

摘　　要：对发震构造呈复杂几何关系(发震构造在平面投影呈非平行关系)下彼此发震影响的机理进行了研究。从发震的"垂震底继"影响关系研究了1933年迭溪地震M7.5和1976年松潘MS7.2地震对后来发生汶川M8地震的龙门山地震构造的孕震能量叠加的加震作用;同时也指出汶川8级地震对周边断裂的减震作用,计算并指出了其影响减震的距离。研究对CPSHA中对发震构造呈复杂几何关系时,如何确定地震带内各潜在的震源空间分布函数fi,mj提供了大震加减震的判断理论依据。还讨论了汶川地震孕震模式的更复杂性,针对某些用巴颜喀拉块体向东南方向移动挤压龙门山孕震构造,进而解释汶川地震的逆冲性所带来的矛盾的观点,对其孕震的复杂性提出了问题所在和初步探讨。The influence of seismogenic structures with complex geometric relationships,in which the seismogenic structure is not parallel in the planar projection,on the mechanism of earthquakes is studied.Seismogenic structures that influence each other have a damping effect on regional earthquakes after their occurrences.However,the mechanical mechanism research shows that when the fault distribution is of complex geometry,the increasing and decreasing effect of earthquakes differ.Perpendicular intersectional faults are known as perpendicular faults;those equivalent to the bottom line are known as bottom faults.If an earthquake has occurred on the bottom fault,the perpendicular fault will have damping effect,which is known as the occurrence of an earthquake on a bottom fault following the occurrence of an earthquake on a perpendicular fault.If a strong earthquake has occurred on the perpendicular fault,a strong earthquake occurring on the bottom fault is known as the occurrence of a smaller earthquake on a perpendicular fault following the occurrence of an earthquake on a bottom fault.When earthquake occurs on a bottom fault,the relation between magnitude M and damping distance R to the perpendicular fault islg R=0.49 MS-1.97（1） where R is the damping distance in kilometers and MS is magnitude.When an earthquake occurs on a perpendicular fault,which is nearly at a right angle with the bottom fault,energy accumulates in the bottom fault.This result is conducive to damping and is more conducive to the accumulation of energy for earthquakes.When the distance between the top and the end parts of a seismogenic fault on a perpendicular fault is approximately 2~3 times the length L of the seismogenic fault on the perpendicular fault,energy may be superimposed on the bottom fault.The relation between length L and magnitude M on the perpendicular fault islog L=0.48M-1.57（2） Using the relationship of the occurrence of a smaller earthquake on a perpendicular fault following the occurrence of an earthquake on a bottom fault,

关 键 词：发震构造 相互影响 2008年汶川地震 1933年叠溪地震 1976年松潘地震 汶川地震孕震模式 巴颜喀拉块体 

分 类 号：P315.1[天文地球—地震学]