研究人员对8个地质数据集进行了详细的分析，以限制地球从650万年到240万年的自转历史。这些结果使他们能够测试物理潮汐模型，并指出地球从650-280Mya减速的阶梯模式。在这段时间间隔内，地月距离增加了约20,000km，日长增加了约2.2h。
具体来说，地球自转减速有两个时段，分别是650-500Mya和350-280Mya，由500-350Mya的减速停滞期隔开。
减速停滞的时间间隔主要被归因于当时大陆—海洋结构导致的潮汐耗散减少，而不是大陆组合或冰川作用导致的地球动力椭圆率的变化。模拟显示，除了最近的时间外，潮汐耗散是地球自转减速的主要驱动因素。研究发现的一个潜在含义是，地球的潮汐耗散，随着地球自转减速，可能在地球进化中发挥作用。
据介绍，由于潮汐耗散，地球的自转在其整个历史中一直在减速，但这种减速率随时间的变化尚未确定。
附：英文原文
Title: Geological evidence reveals a staircase pattern in Earth’s rotational deceleration evolution
Author: Huang, He, Ma, Chao, Laskar, Jacques, Sinnesael, Matthias, Farhat, Mohammad, Hoang, Nam H., Gao, Yuan, Zeeden, Christian, Zhong, Hanting, Hou, Mingcai, Wang, Chengshan
Issue&Volume: 2024-8-6
Abstract: 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.
DOI: 10.1073/pnas.2317051121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2317051121