【摘要】 本文讨论了在构造应力水平达到岩石破裂临界值时引潮力、潮汐附加应力的动态变化与地震序列之间的关系,选用了中国大陆1970年以来7级以上地震序列资料,分析了引潮力水平分量动态变化与强震发震时间之间的关系,结果显示在一定时空范围内前震、主震及余震序列发震时刻的引潮力存在优势方向,多数地震发震时刻与选取时段引潮力水平分量的方位角相位比平均值仅为35%;对于构造复杂地区,结果显示引潮力水平分量的方位角不仅存在一个优势方向,还明显存在其他优势方向,可能与发震构造有关.根据1966~1976年中国九大地震震源机制解计算潮汐正应力和滑动方向的剪应力及其变化率,结果显示多数地震发震时刻潮汐剪应力接近最大值.更多还原

【Abstract】 This paper focuses on the relationship between seismic sequences and dynamic changes of tidal force and additional tidal stress when geological structure stress reached the critical value of rock failure. Some earthquakes above M_s 7.0 and their seismic sequences in Chinese mainland since 1970 were selected to analyze the relationship between dynamic changes of horizontal tidal force and large earthquakes occurrence. The result showed that the tidal force had an advantage azimuth range at the times of foreshocks, main shocks and aftershocks in certain spatiotemporal range. The average phase ratio of the azimuth range of horizontal tidal force at the time of triggered earthquakes was only 35% of total azimuth ranges in the chosen period. For some complex structural areas, there might be more than one advantage range of azimuth, which was related to seismogenic structure probably. According to focal mechanisms of 9 great earthquakes in China from 1966 to 1976, tidal normal stress, shear stress and their change rates in slip orientation were calculated. The results showed that the tidal shear stress were nearly of their maximal value at the moment of earthquake occurrence.更多还原