© University of Alberta
"In order to fully understand the sea-level change that has occurred in the past century, we need to understand the dynamics of the flow in Earth's core," says Mathieu Dumberry, a professor in the Department of Physics at the University of Alberta.
The connection is through the change in the speed of Earth's rotation. Meltwater from glaciers not only causes sea levels to rise, but also shifts mass from the pole to the equator, which slows down the rotation. (Picture the Earth as a spinning figure skater. The skater moves his or her arms in to spin more quickly or out to slow down.) The gravity pull from the Moon also contributes to the slowdown, acting a little like a lever brake. However, says Dumberry, 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.
