Due to climate change, melting glaciers are slowing down the Earth's rotation and gradually lengthening the day. By the end of the century, this factor may influence the length of the day more than the gravitational pull of the Moon, the University of Vienna reported on May 12, citing a study by scientists from the university and ETH Zurich.
As the researchers explained, the length of the day is now increasing by about 1.33 milliseconds per century. The reason is the melting of polar and mountain glaciers, which causes sea levels to rise, mass to be redistributed on the planet and, as a result, the rotation of the Earth slows down.
One of the study's authors compared this process to a figure skater: when an athlete spreads his arms out to the sides, he rotates slower, and when he presses them closer to his body, he rotates faster.
To find out whether something similar happened in the past, scientists analyzed the fossilized remains of single-celled marine organisms – benthic foraminifera. Using their chemical composition, the researchers reconstructed fluctuations in sea level, and then mathematically calculated how this could affect the length of the day.
According to the authors' conclusions, during the last 3.6 million years there were periods when the growth and melting of large ice sheets changed the length of the day. However, the current lengthening of days recorded in 2000–2020 stands out against the backdrop of the entire climate history of this period.
Scientists also noted that by the end of the 21st century, the influence of climate on the length of the day may exceed the influence of the Moon.
“Although we are talking about changes in the millisecond scale, they can potentially affect systems that require high precision, in particular space navigation,” the university concluded.
