Global warming is slowing Earth’s rotation, according to a team of researchers at Harvard University who managed to solve a scientific mystery dating back twenty years.
In a paper – published December 11 in the journal Science Advances – researchers wrote that the melting glaciers will impact Earth’s rotation, slowing it.
Over the past 100 years, the duration of a day on planet Earth has lengthened by a millisecond, according to the researchers at Harvard. As the melted ice from the poles gets into the ocean, it shifts the weight of Earth’s water from the planet’s axis to the Ecuador. This causes the rotation of planet Earth to wobble and slow. The days get longer as Earth’s rotation slows, researchers say.
Jerry X. Mitrovica, lead author of the study and a Professor of Geophysics at Harvard University, said that when glaciers melt – which are tipically located at high latitudes – they redistribute all that water to lower latitudes. Earth’s rotation rate is thus slowed.
Because the glaciers will not melt symmetrically, and water will move more to some parts of the planet than others, Earth’s rotation will also wobble, Mitrovica explained.
Dr. Walter Heinrich Munk – a famous physical oceanographer (sometimes called the “Einstein of the oceans”) who holds the Secretary of the Navy/Chief of Naval Operations Oceanography Chair at Scripps Institution of Oceanography – suggested that the melting glaciers would change Earth’s rotation.
However, he predicted that the glacial melt would make the duration of Earth’s days shorter and not longer. But Dr. Munk did not account for the liquid core of the planet, which is important in slowing Earth’s rotation, and his estimate of sea level rise over the 20th century was 30 percent higher than the actual rise.
Mitrovica says that although the change is far from being significant at this point, it should not be overlooked, because it will only accelerate in time as the melting of the polar ice caps increases. Even if it is only an extra millisecond, it still adds further confirmation that global warming is truly impacting our planet, he added.
By 2100, scientists estimate that about 18 to 85 percent of the Earth’s glaciers will be lost, and Earth’s rotation will slow even more.
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