Why are earthquakes nudging the pole towards 140 E?

Earthquakes have collectively the tendency to displace the pole of rotation of the earth towards a preferred direction (∼140°E). This trend, which is still unexplained on quantitative grounds, has been revealed by computations of earthquake‐induced inertia variations on both a secular and a decade time‐scale. Purpose of this letter is to show that the above trend results from the combined effects of the geographical distribution of hypocenters and of the prevailing dip‐slip nature of large earthquakes in this century. Our findings are based on the static dislocation theory and on simple geometrical arguments.