By tass.ru - JUN 16, 2023, 09:26

This eventually played a role in sea level rise.

Between 1993 and 2010, humans moved such a large mass of water by pumping it out of the ground that our planet tilted almost 80 cm to the east. This is reported by the authors of a study published in  Geophysical Research Letters.

"The Earth's axis of rotation actually changes a lot," said Ki Won Seo, lead author of the paper, a geophysicist at Seoul National University. "Our study shows that among climate-related causes, groundwater redistribution actually has the biggest impact on axis shift. rotation".

Scientists discovered the impact of water on the Earth's rotation axis back in 2016, but the contribution of groundwater to these changes has not yet been studied. In the new study, the research team created a computer model of the observed changes in the tilt of the Earth's axis of rotation and the movement of water. At first, the modeling included only ice sheets and glaciers, and then also various groundwater redistribution scenarios.

The resulting picture began to match observed changes in the earth's axis only after the researchers included 2,150 gigatonnes of displaced groundwater. Without them, the model deviated from the real changes by 78.5 cm.

The axis of rotation of the Earth usually shifts by about a few meters during the year, the authors of the work noted. Therefore, changes due to the pumping of groundwater do not carry a global risk, for example, the change of seasons. But on a geologic time scale, a change in the tilt of the planet could have an impact on the climate, the scientists concluded.

Earth's axis is currently tilted 23.4 degrees, or about halfway between its extremes, and this angle is very slowly decreasing in a cycle that spans about 41,000 years. It was last at its maximum tilt about 10,700 years ago and will reach its minimum tilt about 9,800 years from now.