Human activity shifted Earth's axis by 80 centimeters, study finds

A recent study published in Geophysical Research Letters reveals that human activity, particularly the over-pumping of groundwater, has shifted Earth's axis by 31.5 inches (about 80 centimeters) over the past two decades. Researchers modeled the observed changes in the drift of the Earth's rotational poles and the movement of water, first considering ice sheets and glaciers, and then adding different scenarios of groundwater redistribution.

“Earth's rotational pole actually changes a lot. Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole,” explained Ki-Weon Seo, a geophysicist at Seoul National University and the study's lead author. Seo was quoted in a report by The Independent. The researchers found that the model was off by 78.5 centimeters (31 inches), or 4.3 centimeters (1.7 inches) of drift per year when considering 2,150 gigatons of groundwater redistribution.

Between 1993 and 2010, the extraction of 2,150 gigatonnes of groundwater has displaced the balance of our planet, primarily for human consumption, agriculture, and various industries. The massive movement of water from land areas to the oceans has modified the natural balance of the Earth, similar to adding weight to a spinning top, according to SciencePost.

Groundwater is fresh water that accumulates in the soil's pores and rock crevices beneath the Earth's surface, forming part of the hydrologic cycle and is stored in aquifers. The global extraction of groundwater has been on the rise, mainly for purposes of irrigation and human consumption, particularly in India and the United States, as the rapidly growing world population and climate change have increased demand, reported by Mirror.

Researchers found that water redistribution can change the planet's rotation and impact sea level rise, which can have cascading repercussions on ecosystems, weather, and human habitats, according to News18. The movement of Earth's rotational pole is influenced by the distribution of water, which affects the planet's mass distribution, as stated by The Independent.

The amount of groundwater pumped and shifted during this period is enough to raise sea levels by 0.24 inches.

“I'm very glad to find the unexplained cause of the rotation pole drift. 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,” Ki-Weon Seo said.

Other factors, such as ice melting and the rise in ocean levels, also contribute to fluctuations in the Earth's rotation axis, according to NASA.

Surendra Adhikari, a scientist from NASA’s Jet Propulsion Laboratory, warned that these shifts could have unpredictable effects on the planet’s delicate balance.

Conservation strategies aimed at reducing groundwater extraction could potentially alter the trajectory of polar drift if implemented consistently over decades, according to The Independent.

The findings suggest that the location from which groundwater is drawn matters for how much it could change polar drift. “Observing changes in Earth's rotational pole is useful for understanding continent-scale water storage variations. Linking these variations to water movement shows how everyday actions can impact the Earth on a global scale," Seo stated.

While the recent tilt won’t alter seasons, it could influence global climate patterns and affect seasonal weather patterns over extended periods.

This article was written in collaboration with generative AI company Alchemiq