news

한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina

Chengdu, August 7 (Xinhua) -- A Chinese and foreign research team has recently found that the Earth's rotation has slowed down in a step-by-step manner over the past 700 million years. Between 700 million and 200 million years ago, the distance between the Earth and the Moon increased by about 20,000 kilometers (about 4 meters per century), and the length of the day increased by about 2.2 hours (about 1.58 milliseconds per century).

This research result was published in the international academic journal Proceedings of the National Academy of Sciences (PNAS) on August 7 under the title "Geological evidence reveals a staircase pattern in Earth's rotational deceleration evolution". The first author and corresponding author of the paper are Researcher Huang He and Professor Ma Chao from the Institute of Sedimentary Geology of Chengdu University of Technology.

Previously, a scientific research team found that the melting of glaciers caused by global warming is slowing down the rotation of the Earth at a significant rate, which has attracted widespread attention from academia and society.

In fact, in the geological history, the phenomenon of slowing down the Earth's rotation has always existed due to the tidal dissipation caused by the Earth-Moon gravity. But is the rate of slowing down the Earth's rotation in the geological history the same as it is today?

To address this problem, the big data sedimentation team of Chengdu University of Technology, in collaboration with the team of internationally renowned astronomer Jacques Laskar and teams of stratigraphers from Germany and Ireland, worked together for two years to obtain the Earth's rotation parameters from 700 million to 200 million years ago. Through astronomical theoretical calculations, they obtained the Earth's rotation period and the distance between the Earth and the Moon.

These results can independently verify the reliability of tidal models and reveal a step-wise pattern of Earth's rotation deceleration between 700 million and 200 million years ago. In addition, this study shows that supercontinent aggregation and glacier development during geological history also affect the Earth's rotation rate.

The calculation results of this study also show that when the Earth's rotation speed slows down to a certain extent, tidal dissipation will no longer be dominant. By comparing biological evolution data and marine geochemical data of the same period, the study also found that the two major deceleration periods of the Earth's rotation may have provided the necessary conditions for the evolution of early marine ecosystems.

This study also has important theoretical significance for reconstructing the evolutionary history of the Earth-Moon system and exploring the climate, environment, and biological evolution of the Earth's deceleration. (End)

【Editor: Zhang Ziyi】