Melting glaciers slow the rotation of the Earth

(written by lawrence krubner, however indented passages are often quotes). You can contact lawrence at:


At issue is a scientific quandary known as “Munk’s enigma,” which was introduced by famed oceanographer Walter Munk in a 2002 paper published in Proceedings of the National Academy of Sciences. The enigma refers to a key discrepancy between the amount of sea-level rise believed to have occurred during the 20th century and the effects it should have produced on the planet — specifically, on the Earth’s rotation.

The planetary effects of sea-level rise

That’s right — in addition to all the devastating and obvious effects sea-level rise will produce on the planet, such as flooding and erosion, sea-level rise also has the more subtle, but nonetheless mind-boggling ability to alter the way the Earth rotates on its axis.

“If you melt ice sheets or glaciers, which happen to be close to to the poles, and all of that mass moves from the poles toward the equators, that movement is very similar [to] a figure skater who puts her arms out,” said the new paper’s lead author, Jerry Mitrovica, a professor of geophysics at Harvard University. “The melting of glaciers acts to slow the spin of the Earth in a measurable way.”

Additionally, glacial melt can also cause the Earth’s rotation to wobble a little, since “the melting of glaciers isn’t perfectly symmetrical, and the water will move more in some parts of the Earth than others,” Mitrovica said.