PLATE MOTION AND THE SECULAR SHIFT OF THE MEAN POLE

摘要

Recent development of the global plate motion indicates that changes in the products of inertia of the earth due to tectonic plate movement may provide a secular shift of the mean pole. In this paper we present a mathematical pro¬cedure for calculating this shift based on the plate theory. Explicit expressions are obtained for the dependence of the secular polar shift on the dimensions and locations of the plate boundaries. Numerical results show that the secular motion of the mean pole is 01'0002 year in the direction of 67°W. Hence, it is deduced that the influence of the plate motion on the secular polar shift may account for 10% of the observed value.