The Earth’s rotation is accelerating, a new record-breaking

English time and date website In an article dated July 28, he explains that this acceleration is the last “in a string of speed records since 2020”. Christian Besward notes that “Since 2016, we have observed that the speed of the Earth’s rotation is accelerating, and therefore the length of the day is decreasing! The astronomer studies this phenomenon Inside the Sirte Research Laboratory (Space-Time Reference Systems), and explains that this observation is, to say the least, unexpected with respect to previous observations. Since 1830, we have observed a decrease in the speed of Earth’s rotation. This trend has been reversed for seven years without being able to explain it. Thus, the fastest 28 days since 1930 are recorded in 2020.

2 milliseconds

This difference does not concern the French astronomer because the rotation of the Earth has always been irregular. Its duration increases by about 2 milliseconds every century.

For Christian Bezouar, “80% of changes in Earth’s speed are wind related.” Another reason is tides, which are strong enough to produce 10 to 20% changes in rotation time.

But other fluctuations are difficult to explain. “It is believed to be caused by internal movements in the Earth, molten magma under the mantle. But we do not have any observations of solid core, such as those made in the atmosphere, that would validate these hypotheses.” However, the scientist specifies that the assertion On whether global warming is in question, it would be “pure guesswork.”

set clocks

If we don’t have to worry about that acceleration, for international timekeepers, which allow us to set our clocks, that’s another story. These ultra-accurate atomic clocks are used to measure Coordinated Universal Time (UTC). Thus, since 1972, the International Earth Rotation and Reference Systems Service regularly adds a “leap second” to the year, at the end of June or the end of December. There have been 28 so far. La dernière remonte au 31 décembre 2016. » La récente accélération de la Terre pourrait ainsi remettre en cause ce procédé comme l’explique Christophe Bizouard : « Pour la première fois, si la Terre continue d’accélérer à tre pour ramené the second. It never happened. »