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本文应用弹性半无限空间内均匀膨胀的球体对球上介质的作用,作为地幔快速上涌触发构造地震的力学模型。按照地面垂直位移的年变化率,利用这个模型反推出这种虚拟的膨胀球的半径和膨胀强度。並计算出它在地壳中产生的附加应力。尽管此种附加应力比驱动地壳水平运动的力要小得多,但它能在高倾角断层上引起张性的法向应力,而且在隆起区内还有较高的附加剪应力。这些应力比固体潮、地极移动和地球转速变化等因素产生的附加应力都大得多。因此,地幔快速上涌对构造地震的触发作用应该比上述诸因素更大。由于近十余年来我国不少地区的走滑型强震大都发生在地壳上隆区或者在其边缘,而且发震断层都是高倾角断层,因此,本文能够对此作粗浅的解释。
In this paper, we use the effect of uniformly expanding spheres in the elastic semi-infinite space on the medium of the ball, and use it as a mechanical model to trigger the rapid upwelling of the mantle. According to the annual rate of change of the vertical displacement of the ground, this model is used to deduce the radius and expansion strength of the virtual bulging sphere. And calculate its additional stress in the earth’s crust. Although this additional stress is much less than the force driving the horizontal movement of the crust, it can cause tensile normal stress on high dip faults and higher additional shear stresses in the uplift. These stresses are much greater than the additional stress generated by factors such as solid tide, movement of the poles and changes in the earth’s rotation speed. Therefore, the rapid upwelling of the mantle should trigger the tectonic earthquake more than the above factors. Since most of the strike-slip strong earthquakes occurred in many parts of China in the past ten years occurred in the crust or at the edge of the area, and the seismogenic faults are all high-angle faults, this article can provide a superficial explanation.