地球自转速率变化引起的全球应力场

GLOBAL STRESS FIELD CAUSED BY THE CHANGE OF RATE OF THE EARTH’S ROTATION

本文用有限元方法计算了地球自转变化引起的全球应力，包括离心惯性力和纬向惯性力引起的应力。离心惯性力变化引起的应力其主方向为ＳＮ向和ＥＷ向，应力的大小随着地球自转角速度的持续增加而积累，其量级可能达到几十到几百兆帕或更大。纬向惯性力引起的应力，在均匀地球的情况下，主应力方向为ＮＥ向和ＮＷ向。在地壳厚度按一定规律分布时，应力场的分布沿ＥＷ方向具有分带性，并且与全球大洋中脊的分布有对应关系，但应力幅度很小。

In this paper,a global stress field caused by the change of rate of the earth's rotation is calculated using finite element method.The principal stress resulting from the change of centrifugal inertial force is South North and East West oriented,and the magnitude of the stress may reach to tens to several hundreds MPa.The principal stress caused by latitudinal inertial force for a homogeneous earth is Northeast and Northwest oriented.With a varying crustal thickness along the longitude,there will be a zoning of the stress field caused by latitudinal inertial force with the resulting 4 tension zones corresponding to the locations of the present 4 Mid oceanic ridges.