Chinese scientists revealed patterns in Earth's rotational deceleration
Chinese researchers have discovered that, between 650m and 280m years ago, the Earth-Moon distance increased by approximately 20,000km, and the length of a day extended by roughly 2.2 hours, Xinhua reports
As the Science and Technology Daily reported recently, the Earth's rotation has been slowing over time due to tidal dissipation, but the rate of this deceleration has not been consistently established, according to a relevant research article published in the journal Proceedings of the National Academy of Sciences.
The researchers analysed eight geological datasets to reconstruct the Earth's rotational history from 650 million to 240 million years ago. Their findings enabled them to test physical tidal models and identify a staircase pattern in the Earth's deceleration.
Specifically, there are two periods with high Earth rotation deceleration – from 650 to 500 million years ago and from 350 to 280 million years ago – separated by an interval of stalled deceleration from 500 million to 350 million years ago.
As noted in the publication, these two periods roughly coincided with the Cambrian explosion and the largest mass extinction event in Earth's history, and they may have provided the necessary conditions for the evolution of early Marine ecosystems. Modelling indicated that, except for the very recent time, tidal dissipation is the main driver for decelerating Earth's rotation.
According to Professor Ma Chao, from the Chengdu University of Technology, the study has important theoretical significance for exploring the climate, environment and biological evolution of the Earth's rotation deceleration.
The team of researchers will further study the internal links between the Earth's rotation changes and natural phenomena such as the Earth's magnetic field, tidal actions and climate change in order to build a more comprehensive and accurate Earth system evolution model.
