Abstract A number of moderate earthquakes occurred in the South China continental edge or coastal area. Several large earthquakes are sparsely distributed along the seismic belt with the northeast direction between the South China and the continental shelf of the South China Sea. Coulomb stress changes of the 1969 Yangjiang main shock (Ms 6.4) with the following events of the 1986 ML 5.4, the 1987 ML 5.4 and the 2004 ML 5.2 in the Yangbian Bay area are studied. The complex stress patterns of the main shock caused by the dextral Pinggang strike-slip fault imported on the planes of the normal fault, strike-slip fault and thrust fault of three events indicate that the distribution of aftershocks mainly located in the areas of positive stress changes and part of aftershocks fall into the stress shadow area due to the reactivity of the local faults. The 1969 Yangjiang event occurred between the intraplate and the broad plate boundary zone setting when we apply on the empirical relationship between the aftershock durations and the fault-loading rate. The intersection fault model is proposed and could explain the stress changes of the Yangjiang earthquake sequences in South China coastal area. The future hazard assessment requires to take account of the stress increase area along the tip of the main shock source fault and off-fault stress increase area.

中文翻译：

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华南沿海地区板内大地震与静应力变化

摘要 华南大陆边缘或沿海地区发生了多起中度地震。数次大地震沿地震带稀疏分布，分布在华南与南海大陆架之间的东北向。研究了阳边湾地区1969年阳江主震(Ms 6.4)与1986年ML 5.4、1987年ML 5.4和2004年ML 5.2事件的库仑应力变化。平冈右旋走滑断层在正断层、走滑断层和逆冲断层三个事件平面上输入的主震的复杂应力模式表明，余震主要分布在正应力区。由于局部断层的反应性，变化和部分余震落入应力阴影区。1969年阳江事件发生在板内和宽板边界带设置之间，当我们应用余震持续时间与断层加载率之间的经验关系时。提出了交叉断层模型，可以解释华南沿海地区阳江地震序列的应力变化。未来的灾害评估需要考虑沿主震源断层尖端的应力增加区和断层外应力增加区。