Ancient sea levels suggest Earth's poles shift due to plate tectonics

Ancient sea-level changes offer evidence regarding the movement of Earth's geographic poles. Plate tectonics and mantle convection drive true polar wander by redistributing mass within the Earth’s mantle.
These true polar-wander events cause the solid outer layers of the globe to shift to find a new stable spin equilibrium. Geological records show the geographic poles shifted dramatically four times in the past, spanning periods of roughly ten million years.
Mathew Domeier noted that the speed of polar motion surpassing about 0.6 degrees per million years exceeds most tectonic plate movement rates. True polar wandering continues today, with satellites measuring the rate at approximately 10 centimetres per year.
Sabin Zahirovic stated that the Earth’s 2800-kilometre-thick outer shell, comprising the crust and mantle, moves relative to the planet’s spin axis.



























