Scientists have discovered why the length of a day changes slowly

Scientists have discovered why the length of a day changes slowly

The length of a day on Earth is not constant. For several decades, scientists have been recording slight fluctuations in the rotation speed of our planet. Usually, these fluctuations are only a few milliseconds, so people do not notice these changes; however, they are of great scientific interest to geophysicists.

Previously, researchers have established that the speed of Earth's rotation is influenced by processes in the atmosphere and oceans, major earthquakes that redistribute the planet's mass, and the melting of continental glaciers that alters the distribution of water in the world's oceans.

However, these factors explain only a part of the observed changes. Over longer time intervals, the causes appear to be hidden deep within the Earth.