Statistical analysis of tidal stress effect on seismic faults

Tidal stress components along P axis and T axis of 1069 earthquake focuses distributed in China and its neighbor areas are calculated. Partterns of ti dal stress effect on the earthquake faults are analyzed. Statistics of seis mic fault types related to slip-accelerating effect of tidal stress and rel ationship between the types and the patterns are made for various latitude areas. The following features are obtained: Proportion of the number of sei smic faults related to the slip-accelerating effect of tidal stress has dec reasing trend with latitudinal rising. Among them, proportion of the strike -slip faults in low latitude area is comparatively large but that of the di p-oblique-slip faults in middle high latitude area is comparatively large. The patterns of tidal stress effect of slip acceleration are classified int o compression-adding type and compression-reducing type. For the whole area , proportion of the number of seismic faults affected by the compression-ad ding type is larger than that affected by the compression-reducing type. Fo r different latitude areas, various patterns of tidal stress effects and re levant types of seismic faults have various distributing features.