Scientists link changes in Earth's day length to core-mantle forces

A University of Alberta study found that angular momentum exchange between Earth's core and mantle changed the length of the day by several milliseconds between the early 1970s and 2021. Gravitational coupling had the strongest influence, while electromagnetic and topographic effects acted in the opposite direction.

• Day length changed by several milliseconds between the early 1970s and 2021
• Gravitational coupling between core and mantle was the dominant factor
• Electromagnetic and topographic effects offset each other
• The study was published in the journal Nature