Ancient eclipse records used to calculate changes in speed of Earth’s spin
The new study shows that the Earth’s rotation is slowing down as a result of melting glaciers and rising sea levels. (NASA)
With human-caused climate change, we puny creatures are having some powerful effects on our entire planet, including one you might not imagine was possible — making it spin more slowly.
The melting of glaciers near the Earth’s poles and the resulting rise in sea level is slowing down the Earth’s rotation and making each day a little longer, a new study confirms.
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Scientists had predicted it would happen, but to their puzzlement, they couldn’t measure much of an effect.
Glaciers contain a huge amount of mass near the poles, close to the Earth’s axis of rotation, which runs from pole to pole. When glaciers melt, the meltwater ends up in the oceans, which have most of their volume near the equator, farther away from the Earth’s axis.
Scientists measure changes in the speed of the Earth’s rotation over thousands of years by looking at records of ancient eclipses recorded by civilizations such as the Babylonians, says Mathieu Dumberry, a physics professor at the University of Alberta. (John Ulan)
Just as a spinning figure skater slows down as she extends her arms out from her chest, moving mass away from the Earth’s axis of rotation should slow the Earth down, says Mathieu Dumberry, a physics professor at the University of Alberta who co-authored the paper published today in the journal Science Advances.
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