The massive extraction of groundwater between 1993 and 2010 modified the planet’s rotation, according to a recent study.
In particular, more than 2,150 gigatons were pumped, an amount equivalent to adding 6 millimeters to the global sea level.
This precisely caused the Earth’s axis to tilt 0.80 meters eastward.
This natural phenomenon shows how the rotation pole shifts slightly over the Earth’s surface.
That is, when the planet’s mass distribution changes, its rotation changes.
The analysis was published in Geophysical Research Letters by the team of Ki-Weon Seo from Seoul National University.
The redistribution of water and its underground extraction changes how the planet spins
Climate models already estimated these levels of groundwater extraction.
However, accurately measuring the loss of water in continental aquifers is technically complex.
Therefore, scientists needed an independent way to verify these figures, and the answer came from the polar motion.
This natural phenomenon describes how the rotation pole shifts slightly over the Earth’s surface according to the planet’s mass distribution.
When the distribution of water changes, rotation changes. Like a skater spinning differently when opening or closing their arms, the Earth responds to these weight variations.
The team led by Ki-Weon Seo compared different scenarios to reach their conclusion regarding the impact on the Earth’s axis of groundwater extraction.
First, they analyzed only ice and glaciers, then added the extracted groundwater.
The risks of groundwater extraction
Despite the discovery, it should be noted that the axis shift does not pose an immediate risk to stations or short-term climate.
In general, the natural polar motion oscillates several meters each year.
However, the rapid depletion of aquifers does have environmental impacts, as aquifers recharge slowly.
When they are pumped faster than they regenerate, impacts are triggered across the surface.
Due to this, it may occur that reduced wetlands, rivers with less flow, and part of the soil sinks in urban and agricultural areas.
This happens because the water transferred from land changes the dynamics of sea level.
The shift indicates a global imbalance. A signal that the planet redistributes water masses on a large scale, coinciding with the deterioration of strategic aquifers for food and biodiversity.
Two critical regions: India and North America
The location of pumping is as important as the volume extracted.
The greatest alterations occur when the water comes from mid-latitudes, where the effect on the axis is more pronounced.
During the studied period, two critical hotspots were identified: the western North America and northwestern India.
Both regions maintain structural pressure on their aquifers.
According to Seo, if countries reduced extraction in sensitive areas, a change in trend could be observed.
However, decades of responsible management are needed for the polar motion to respond.
