A team led by Chinese researchers, in collaboration with experts from France, Germany, and Ireland, has uncovered intriguing patterns in the Earth’s rotational deceleration. Their recent study, published in Proceedings of the National Academy of Sciences (PNAS), highlights that between 650 million and 280 million years ago, the distance between the Earth and the Moon increased by approximately 20,000 kilometers, while the length of a day extended by about 2.2 hours.
The Earth’s rotation has been gradually slowing down due to tidal dissipation, but the exact rate of this deceleration has been a subject of debate. By analyzing eight geological datasets, the researchers reconstructed the Earth’s rotational history over this extensive period. Their findings revealed a staircase-like pattern in the deceleration, with two distinct periods of high slowdown: from 650 to 500 million years ago and from 350 to 280 million years ago. These periods were separated by a phase of stalled deceleration from 500 to 350 million years ago.
Interestingly, these high deceleration periods coincided with the Cambrian explosion and the largest mass extinction event in Earth’s history. The study suggests that these changes in rotation may have created the necessary conditions for the evolution of early marine ecosystems.
According to Professor Ma Chao from the Chengdu University of Technology, tidal dissipation has been the primary driver of the Earth’s rotational slowdown, except in very recent times. The research holds significant implications for understanding how changes in Earth’s rotation have influenced climate, environment, and biological evolution.
The research team plans to delve deeper into the connections between Earth’s rotational changes and natural phenomena such as the planet’s magnetic field, tidal actions, and climate change. Their goal is to develop a more comprehensive model of Earth’s system evolution.
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China-led team reveals patterns in Earth's rotational deceleration
cgtn.com
