摘要
本文计算了我国西南地区给出断面解的104个(M≥4(3/4))地震的潮汐应力位相。按震源应力场分类进行研究结果表明:正断层地震与潮汐流体静应力有一定相关性。走滑和逆断层地震与潮汐最大剪应力有明显关系。三类主压应力轴方向不同的走滑、逆断层地震,其沿断层错动矢量的潮汐剪应力位相特征不同;主压应力轴近南北走向和近东西走向的地震与沿断层错动矢量的潮汐剪应力有关,前者具有高位相的优势分布,后者具有低位相的优势分布。上述结果反映地震和潮汐的关系与地震震源应力场存在直接的关系;地震震源应力场不同,潮汐应力对地震的触发机制也不同。
In this paper, the phases of the solid tidal stress for 104 earthquakes(M≥4(3/4)), given the focal mechanism solution and occurred insouth-wester China, have been calculated and their phases have been classified and studied according to focal stress field.The results show that: There is a certain correlation between the earthquakes and tidal hydrostatic stress for the normal fault type, while the eaethquakes have anapparent correlation with the maximum tidal shear stress for the strike-slip and thrust fault type. For three types of earthquake of strike-slip and thrust fault with different direction of principal compressive stress axes, the characteristics of the phase of solid tidal stress along the dislocation vectors of fault are quite different. The earthquakes with principal compressive stress axes near N-S and E-W direction express correlation with the solid tidal stress along the dislocation vectors of fault. There is an optimal distribution of higher phase for the former type, but an optimal istribution of lower phase for the latter type.The above results reflect that the relation between earthquake and earth tides is directly depending upon the focal stress field, and the mechanism of triggering earthquake by tidal stress are different for the different types of stress fieid,
出处
《地壳形变与地震》
CSCD
1989年第1期13-20,共8页
Crustal Deformation and Earthquake
