Over the past nearly twenty years, the Earth has shifted its tilt by over 30 inches, and scientists have finally pinpointed the reason behind this phenomenon.
Research published in the journal Geophysical Research Letters indicates that within a span of less than 20 years, the planet has tilted 31.5 inches, and the cause is surprisingly straightforward.
Although Earth’s rotational pole undergoes numerous changes, one factor stands out as having the most significant effect.
“Earth’s rotational pole actually changes a lot,” explained Ki-Weon Seo, the lead author of the study and a geophysicist.
It turns out that the extraction of groundwater from beneath the Earth’s surface has a significant influence on the planet’s tilt and rotation.
“Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole,” Seo further elaborated.
The research examined data from 1993 to 2010, revealing that the removal of 2,150 gigatons of groundwater caused the Earth to tilt by 31.5 inches.
As the displaced groundwater eventually makes its way to the oceans, this redistribution is also contributing to rising sea levels.
To provide perspective, this tilt corresponds to a 0.24-inch rise in sea level, which is notably significant.
Groundwater is found beneath the Earth’s surface, typically in soil and rock formations, and is mainly sourced from rain or other surface water that seeps into the ground.
Over time, it accumulates in aquifers, which are rock formations capable of holding water until it flows out naturally into springs or wells, or is extracted for use.
Groundwater extraction is often done for domestic use, agriculture, or mining, but it appears to be significantly affecting the planet.
“I’m very glad to find the unexplained cause of the rotation pole drift,” Seo mentioned.
“On the other hand, as a resident of Earth and a father, I’m concerned and surprised to see that pumping groundwater is another source of sea-level rise.”
Surendra Adhikari, involved in NASA research from 2016 that also identified groundwater extraction as a factor in Earth’s axis changes, commented: “They’ve quantified the role of groundwater pumping on polar motion and it’s pretty significant.”
Groundwater pumping is a more pressing issue in certain regions, including parts of North America and northwestern India.
By understanding the implications of groundwater extraction on the planet, researchers hope to address the challenges posed by rising sea levels.
“Observing changes in Earth’s rotational pole is useful for understanding continent-scale water storage variations,” Seo added.