Why is the Earth spinning faster and faster?
Scientists have recorded the shortest day since measurements were made. According to the Time And Date site earth spinning faster and faster, which is the reference for tracking time in the world, June 29, 2022 was the fastest day in our history (since measurements were made, editor’s note). Planet Earth finished its rotation 1.59 thousandths of a second below 24 hours. The last record dates from 2020. The Earth therefore rotates faster on itself.
In order to understand the origin of this acceleration. The scientist affirms that “it is a completely normal and periodic phenomenon that can be explained and modeled. Over one or two years, it is notably established that the speed varies seasonally”.
Several phenomena are at the origin of these fluctuations
First, the “mass transport in the atmosphere, in other words the winds”. These movements are at the origin of 80% of the variations of the speed of the Earth. The second major cause is the tides. Indeed, the latter can modify the surface of the Earth by their movement, their intensity and their variability. For the scientist, phenomenon is strong enough to produce 10 to 20% of the variations in the duration of rotation.
The last phenomenon to underline is the evolution of our terrestrial layer. This is because the molten core at the center of our earth is melting the rocks around it. It is precisely the circulation of this heat, under the earth’s crust, which also influences, over the long term, the duration of our days.
Starry circles arc around the south celestial pole, seen overhead at European Southern Observatory, La Silla Observatory (an astronomical observatory in Chile). The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO. Each circular streak represents an individual star, imaged over a long period of time to capture the motion of the stars across the sky caused by the Earth’s rotation. La Silla is based in the outskirts of Chile’s Atacama Desert at some 2400 metres (7874 ft) above sea level, and offers perfect observing conditions for long-exposure shots like this; the site experiences over 300 clear nights a year! http://www.eso.org/public/images/potw1534a/, CC BY 4.0, via Wikimedia Commons
What about global warming?
It remains to be seen, however, what would be the variations at the origin of the acceleration of the Earth in recent years. Blame it on global warming? If the theory is more and more evoked, that no data allows us to point the finger at this cause: Today, we put everything on the back of climate change. Does the Earth turn more quickly under its effect? We don’t know. To say that is pure speculation.
Nevertheless, we know that certain climatic phenomena, such as earthquakes or hurricanes can influence the length of our days. If global warming announces a multiplication of these phenomena, it risks playing an important role in the variations in the speed of our planet.
Photo credit: Pxhere CC0 Public Domain