Defining an absolute reference frame for plate motions on Earth from minimizing subduction zone trench migration

Abstract

Since the advent of plate tectonics different reference frames have been proposed to describe the ``absolute' motion of plates. The most prominent ones include the hot spot reference frame and the no-net-rotation reference frame. The difference in absolute plate motion between different reference frames can be substantial (up to 4 cm/yr). These differences are truly significant, considering that the velocity of the fast plates is only 6-12 cm/yr in such reference frames. It is thus of primary importance to extract which of these reference frames is most likely to describe the absolute motion of plates. Here we propose that the best candidate representing an absolute reference frame is the one, which minimizes the cumulative amount of trench migration for all subduction zones. From the absolute reference frames proposed thus far, it is found that the cumulative amount of trench migration is lowest in the Indo-Atlantic hot spot reference frame. This implies that the Indo-Atlantic hot spot reference frame is currently the best approximation of an absolute reference frame on Earth.