Earth’s Rotation Is Slowing Down in a Way Different Than Scientists Thought (INFOGRAPHIC)

The Earth’s rotation has slowed throughout history through tidal forces, but the details of this process have not yet been established.

To fix this, a team of geologists from several institutions analyzed data from sedimentary rock samples older than half a billion years in a study published in the Proceedings of the National Academy of Sciences.

The study covered the period from 650 to 240 million years. It turned out that during this time, the slowdown of the Earth’s rotation was not smooth, as previously thought – our planet experienced a series of slowdowns followed by periods of stability, which makes the graph of this process look like a “staircase”.

In particular, two intervals with a high slowdown of the Earth’s rotation can be distinguished:

• 650-500 million years ago;
• 350-280 million years ago;
• They are separated by a slowdown stop interval from 500 to 350 million years ago.

It is noted that during this time the distance from the Earth to the Moon has increased by approximately 20 thousand km, and the length of the day has increased by approximately 2.2 hours.

The Earth transfers angular momentum through tidal dissipation to the Moon’s orbit, causing the Moon’s orbital radius to increase and the Earth’s rotation to slow down, the paper says.

According to scientists, the existence of such a long gap in the process of slowing down the Earth’s rotation is explained mainly by the reduction in the influence of tidal forces due to the configuration of the continents and oceans at that time:

• the beginning of the slowdown period 650-500 million years ago roughly corresponds to the end of the Cryogenian (a period of large-scale glaciations that began about 720 million years ago and lasted about 85 million years). Probably, at that time, a significant part of the Earth’s surface was flooded by the ocean, which led to an increase in the influence of tidal forces – the dissipation of tidal energy occurs, above all, in shallow marine regions;
• The period of stability in the Earth’s rotation rate of 500-350 million years seems to coincide with the drift of the continents toward the South Pole and the significant accumulation of glaciers in this region.

These changes in the Earth’s rotation also coincided with either increases in biodiversity or mass extinctions.

Changes in day length can affect the distribution of solar energy and temperature gradients, which can affect weather systems and atmospheric dynamics, the paper says. — Changes in day length affected the dynamics of Earth’s daily illumination, thereby affecting oxygen production.

Thus, there is a potential link between changes in day length and the evolution of ocean circulation and marine ecosystems, the paper notes.

Source: Racurs

David

I am David Wyatt, a professional writer and journalist for Buna Times. I specialize in the world section of news coverage, where I bring to light stories and issues that affect us globally. As a graduate of Journalism, I have always had the passion to spread knowledge through writing.