Gravitational Torque Primarily Drives Multidecadal Variations in Earth's Day Length

This study reveals that fluctuations in the Earth's length of day over multidecadal timescales are mainly caused by gravitational torque exerted by the inner core. The findings are supported by seismic data on inner core rotation and magnetic field-derived core flows, indicating that gravitational torque dominates while electromagnetic and topographic torques provide resistance. This advances understanding of the core-mantle interactions influencing Earth's rotational dynamics.

Originally published by gnews