The days are getting longer owing to climate changes, revealed a new study. Researchers are studying past changes in sea level in order to make accurate future predictions of this consequence of climate change, and they're looking down to Earth's core to do so.
Mathieu Dumberry said, "In order to fully understand the sea-level change that has occurred in the past century, the University of Alberta researchers need to understand the dynamics of the flow in Earth's core. The connection is through the change in the speed of Earth's rotation."
‘Days are getting longer, and it is a consequence of Earth rotating more slowly. A century from now, the length of a day will increase by 1.7 milliseconds.’
Melt water from glaciers not only causes sea-level rise, but also shifts mass from the pole to the equator, which slows down the rotation. The gravity pull from the Moon also contributes to the slow down, acting a little like a leaver break. However, the combination of these effects is not enough to explain the observations of the slowing down of Earth's rotation: a contribution from Earth's core must be added.
Over the past 3000 years, the core of the Earth has been speeding up a little and the mantle-crust on which we stand is slowing down. As a consequence of Earth rotating more slowly, the length of our days is slowly increasing. In fact, a century from now, the length of a day will increase by 1.7 milliseconds.
Dumberry said, "This may not seem like much. This is a cumulative effect that adds up over time. This study serves as a stimulus for more work to continue investigating the deep interior of our planet."
The findings are published in Science Advances.