论文部分内容阅读
文中计算了由日、月引潮力在地球内产生的潮汐应力场,研究了潮汐应力对地震的触发作用.采用的地球模型是分为十五层的球对称模型.对于近30年来我国或我国邻近发生的七十次较大的地震,计算了震源处在发震时刻的球坐标系中的潮汐应力.通过坐标变换,得到了发震断层面中的正应力及沿错动矢量方向的剪应力.根据岩石的库仑剪破裂准则来判断潮汐应力对所研究的震例是否具有触发作用.结果表明,在七十个震例中,潮汐应力对其中四十三个有触发作用.对于华北地区的十八个震例,潮汐应力对其中十四个有触发作用.还可看出,对于浅源走滑型地震有较明显的触发作用,而对浅源斜滑及倾滑型地震则没有明显的触发作用.对国外七十二个震例的计算结果得到了类似的结论.最后,对华北地区中任一可能的发震地点,提出一种根据潮汐应力来预测发震的危险时间范围的方法.
In this paper, the tidal stress field produced by the tide-day tide force in the earth is calculated and the tidal stress is used to trigger the earthquake.The earth model adopted is a 15-layer spherical symmetry model.For the past 30 years, China or our country In the seventy major earthquakes nearby, the tidal stress in the spherical coordinate system at the time of earthquake occurrence was calculated. Through the coordinate transformation, the normal stress in the seismogenic fault plane and the shear in the direction of the dislocation vector Stress.According to the Coulomb shear fracture criterion of rock, whether the tidal stress has a triggering effect on the earthquake case under study is investigated.The results show that of the seventy earthquake cases, tidal stress has a triggering effect on 43 of them.For North China Of the 18 earthquake cases, the tidal stress has triggered the fourteen of them.It can also be seen that the triggering action is obvious for the shallow-source strike-slip earthquakes, but not for shallow source and slippery-type earthquakes Obvious triggering effect.A similar result is obtained for the seventy-two earthquakes in foreign countries.Finally, a potential time-point for predicting seismogenic events based on tidal stress is proposed for any possible site of occurrence in North China Methods.