引潮力对显著地震触发作用与大震关系的机理讨论  

Discussion on mechanism concerning relation between tidal force triggering of significant shocks and large earthquakes

作　　者：陈荣华[1] 薛艳[1] 郑大林[1] 丁香[2] 

机构地区：[1]中国地震台网中心,北京100036 [2]中国地震局地震预测研究所,北京100036

出　　处：《地震》2006年第1期66-70,共5页Earthquake

基　　金：地震科学联合基金项目(103078)

摘　　要：初步讨论了引潮力对显著地震触发作用与大震关系的机理。结果表明,这一机理是比较复杂的。地震发生时水平引潮力方位与地震断层面走向接近,可能增加断层面上的剪应力,有利于地震的发生;水平引潮力方位与地震主张应力轴T轴接近,可能减小断层面上的正应力,从而减小断层面上的摩擦力,也会有利于地震的发生。所讨论的3个震例中有2个共同点:其一为大震前显著地震发生时水平引潮力方位相互比较接近;其二为显著地震破裂面走向和大震破裂面走向基本一致。The mechanism concerning the relation between tidal force triggering of significant shocks and the large earthquakes is roughly discussed in this paper. Results show that the mechanism is complicated. The tidal force may increase the shear stress on the fault plane and is favorable for earthquake happening if the direction of horizontal tidal force near the fault strike of the earthquake when the earthquake occurs; the tidal force may re duce the compressional stress on the fault plane and reduce the friction force on the fault plane and is also favorable for earthquake occurrence if the direction if horizontal tidal force is near the direction of principal extensional stress T axis of the earthquake. There are two same phenomena in the three examples discussed here. The first is that directions of hori- zontal tidal forces when significant shocks occur are close each other, and the second is that rupture plane strikes of significant shocks before a large earthquake are close to rupture plane strike of the large earthquake.

关 键 词：引潮力 显著地震 触发作用 震例 

分 类 号：P315.72[天文地球—地震学]