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利用一组分布在全球的988个6级或6级以上地震的数据研究了潮汐触发地震的可能性。我们合成了潮汐应力变化的理论时程,包括在地震震中的固体地球和海洋潮汐加载及在每次地震发生时潮汐应力的相位角。Schwiderski将格林函数用于环绕全球海洋潮汐分布的地表点质点的负荷褶积,得到了海洋引起的负荷应力。该函数被用于对Dziewonski和Anderson的初步地球模型的重新计算。通过相位角分布的统计检验,我们发现了正断层类型地震的有效相位选择性;对于体应力分量(潮汐应力张量的迹)的显著性水平为0.54％,对于沿地震震源机制的张力轴上的应力分量为0.58％,并排除了地震发生是随机的、不考虑相位角的零假设。正断层类型地震的最大数量发生在张应力最大的时间上,意味着由固体潮产生的周压的减少对触发地震发生有作用,对于走滑和逆断层类型地震没观察到这种清晰的相位选择性。地震触发的断层类型相关的结果认为:在断层面上的剪切应力改变也是潮汐触发地震的一个主要原因。
Using a set of 988 earthquakes of magnitude 6 or higher distributed around the world, the possibility of tidal-triggered earthquakes is studied. We have synthesized the theoretical time history of tidal stress changes, including the loading of solid earth and ocean tides at the epicenter of the earthquake and the phase angle of tidal stress at each earthquake. Schwiderski used the Green’s function for the load convolution of surface point particles around the global ocean tidal distribution, resulting in ocean-borne stress loads. This function is used to recalculate the initial Earth model for Dziewonski and Anderson. Through the statistical test of phase angle distribution, we found the effective phase selectivity of normal-fault type earthquakes; the significance level of the body stress component (trace of tidal stress tensor) is 0.54%; for the tension axis along the focal mechanism of earthquake Of the stress component is 0.58%, and ruled out that the occurrence of earthquakes is random and does not consider the null hypothesis of phase angle. The maximum number of normal-fault type earthquakes occurs at the time of maximum tensile stress, which means that the decrease of the weekly pressure caused by the solid tide has an effect on the triggering of the earthquake. This clear phase was not observed for the strike-slip and reverse-fault type earthquakes Selective. The result of the type of fault triggered by the earthquake suggests that the change in shear stress on the fault plane is also a major cause of the tidal triggering of earthquakes.