Geological evidence reveals a staircase pattern in Earth's rotational deceleration evolution.

Autor: He Huang, Chao Ma, Laskar, Jacques, Sinnesael, Matthias, Farhat, Mohammad, Hoang, Nam H., Yuan Gao, Zeeden, Christian, Hanting Zhong, Mingcai Hou, Chengshan Wang
Předmět:
Zdroj: Proceedings of the National Academy of Sciences of the United States of America; 8/13/2024, Vol. 121 Issue 33, p1-9, 37p
Abstrakt: The Earth's rotation has been decelerating throughout its history due to tidal dissipation, but the variation of the rate of this deceleration through time has not been established. We present a detailed analysis of eight geological datasets to constrain the Earth's rotational history from 650 to 240 Mya. The results allow us to test physical tidal models and point to a staircase pattern in the Earth's deceleration from 650 to 280 Mya. During this time interval, the Earth-Moon distance increased by approximately 20,000 km and the length of day increased by approximately 2.2 h. Specifically, there are two intervals with high Earth rotation deceleration, 650 to 500 Mya and 350 to 280 Mya, separated by an interval of stalled deceleration from 500 to 350 Mya. The interval with stalled deceleration is attributed mainly to reduced tidal dissipation due to the continent-ocean configuration at the time, not to changes in Earth's dynamical ellipticity from continental assembly or glaciation. Modeling indicates that, except for the very recent time, tidal dissipation is the main driver for decelerating Earth rotation. One potential implication of our findings is that the Earth's tidal dissipation, along with Earth's rotation deceleration, may play a role in the evolving Earth. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index