The rotation of Earth must present a atypical acceleration In July and August this year, contrary to the behavior observed in recent decades. According to predictions based on data from the International Earth Rotation and Reference Systems Service (Iers) And the US Naval Observatory, shorter days will be recorded in the middle of the year, although the exact reason for the change remains unknown to the scientific community.
Since 2020, researchers have been recording a increasing speed in the rotation of planetbreaking the historical tendency of deceleration caused mainly by the gravitational interaction with the Luthe. Although there are plausible explanations for seasonal acceleration events, the standard of recent years draws attention for consistency and lack of predictability.
The IERS will continue to monitor Earth’s rotation to confirm the exact duration of the days in July and August. If the data is confirmed, the planet may hit new records of shorter days ever registered.
Land will have shorter days in July and August
The platform Timeanddate.com points out that July 9 will be 1.30 shorter millisecond than the standard of 86,400 seconds. Other days with reduced duration include July 22 (1.38 ms less) and August 5 (1.5 ms less). These data are the result of calculations based on accurate astronomical observations, using atomic watches.
The phenomenon is particularly relevant for systems that depend on high time accuracy, such as the GPSand would usually be compensated with the addition of a “second leap”. However, since 2016, No extra second was necessaryand Iers has already confirmed that 2025 will not have this adjustment either. Behavior change is seen with surprise by researchers in the area.
Influence of the moon and other geophysical factors
Although the moon is widely recognized for its influence on gradual slowdown From the earth-moving around 3.8 centimeters a year-it can also contribute to temporary accelerations. When the satellite is farther from the terrestrial equatorthe trawl effect decreases, resulting in shorter days.
Furthermore, large magnitude earthquakes They also have the ability to change the speed of rotation of the earth. The 2011 earthquake in Japan, for example, moved the planet axis by 17 centimeters and reduced the length of the day by about 1.8 microsecond. A similar effect was observed in the 2004 earthquake in Indonesia.
“Earthquakes can change the rotation of the earth by redistributing its internal mass,” explained scientist Richard Gross of the jet propulsion laboratory of NASA, Popular Mechanics at the time. “It’s the same principle that a skater uses when pulling her arms to spin faster.”
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Scientists still seek explanations
Despite the hypotheses involving natural factors such as tides, atmosphere and seismic shaking, experts say no current model can completely explain recent acceleration. “The cause of this acceleration is not explained,” he said Leonid Zotovresearcher at the State University of Moscow, to the website Timeanddate.com. According to him, ocean and atmospheric models do not justify the observed intensity.
Judah Levine, a physicist at the US National Institute of Standard and Technology, told the Discover Magazine that the continuous absence of bisexto seconds is a clear sign that the behavior of the planet challenged previous predictions. “The assumption was that the earth would continue to slow down, and that the seconds bisexto would continue to be necessary. This result is very surprising.”
