Posted on 06/06/2026 5:16:00 PM PDT by Red Badger
Water has mass, and mass has leverage. Move enough groundwater from aquifers onto farms, into cities, and eventually into the ocean, and Earth’s spin changes by a measurable amount.
The shift is tiny on a planetary scale, but the number still grabs you: between 1993 and 2010, researchers estimated that groundwater depletion nudged Earth’s rotational pole by about 31.5 inches.
The figure comes from a 2023 study in Geophysical Research Letters, which estimated that humans depleted about 2,150 gigatons of groundwater between 1993 and 2010. When researchers added that water movement to their polar-motion model, the model lined up much better with the observed drift of Earth’s rotational pole. The same groundwater loss equaled about 6.24 millimeters—roughly 0.24 inches—of global sea-level rise.
“Earth’s rotational pole actually changes a lot,” Ki-Weon Seo, a geophysicist at Seoul National University and study lead, says in a statement. “Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole.”
Earth’s rotational pole is not fixed in place. It drifts and wobbles as mass shifts around the planet. In 2016, NASA described the effect in plain mechanical terms: add weight to one part of a spinning top, and it spins a little differently. Earth is not a tabletop toy, obviously, but the physics rhyme. Shift enough water from land to ocean, and the spin axis responds.
This study in Geophysical Research Letters attempts to add some hard figures to that realization. “I’m very glad to find the unexplained cause of the rotation pole drift,” Seo says. “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.”
The study used data from 1993 through 2010 and estimated that the depletion of about 2,150 gigatons of groundwater helped move Earth’s rotational pole roughly 31.5 inches. Much of that pumping was for irrigation and human use, with water that had been stored underground eventually making its way to the oceans.
In the study, researchers modeled observed changes in Earth’s rotational pole and tested different water-redistribution scenarios. The scenario that best matched the observed drift included 2,150 gigatons of groundwater depletion. While the pole motion helped constrain the groundwater estimate, it wasn’t exactly a before-and-after picture of pumps yanking Earth off balance.
Surendra Adhikari, a research scientist at NASA’s Jet Propulsion Laboratory who was involved in the 2016 study, says the additional research is important. “They’ve quantified the role of groundwater pumping on polar motion,” he says in a news release, “and it’s pretty significant.”
Moving water out of the midlatitudes has an outsized effect on polar motion, and the 2023 study pointed to heavy groundwater depletion in western North America and northwestern India as especially important to the modeled drift.
A 2026 Journal of Geodesy reappraisal using the WaterGAP hydrological model found that terrestrial water storage plays a significant role in polar motion across different timescales. But in that model, the longer-term trend was driven mainly by snow-water-storage changes tied to snowfall patterns and Greenland melt, while groundwater and reservoir storage showed up as smaller but still detectable contributors. The paper also found that its modeled long-term trend still didn’t fully agree with GRACE and satellite-laser-ranging observations.
Scientists are also getting better tools for looking backward. In 2026, researchers introduced TWSTORE, a four-decade terrestrial-water-storage reconstruction beginning in 1984, and ML-TWiX, a monthly global total-water-storage-anomaly reconstruction covering 1980 to 2012. Both are attempts to push water-storage records deeper into the pre-GRACE era, where the satellite record is thinner and the uncertainties get harder to ignore.
We still need a longer view is badly needed. Polar motion involves groundwater, snow, ice sheets, glaciers, sea-level redistribution, reservoirs, and processes inside Earth itself. While newer research has tightened some pieces of that budget, it hasn’t yet turned the planet’s wobble into a solved equation.
“Observing changes in Earth’s rotational pole is useful,” Seo says, “for understanding continent-scale water storage variations.”
As for how this affects humans, groundwater depletion can sink land, worsen relative sea-level rise, stress coastal aquifers, and help saltwater push into places that depend on fresh groundwater. A 2026 Nature study of 40 major river deltas found that contemporary subsidence now exceeds absolute sea-level rise as the dominant driver of relative sea-level rise for most deltas studied, with groundwater storage showing the strongest relative influence on vertical land motion in 10 of the 40 deltas. Another 2026 global coastal assessment in Nature Water found statistically detectable groundwater-level trends in 21 percent of gridded coastal areas, with declines becoming more frequent in the most recent nine years of the study.
There is some good news. A 2026 review in Scienceexamined 67 cases of groundwater recovery after interventions and found that aquifers can rebound under the right conditions. The fixes most often involved alternative water supplies, artificial recharge, policy changes, or some combination of the three. But the hard part is that those successes aren’t plug-and-play. A basin that recovers because a city found another water source doesn’t give every dry region the same escape route.
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This is totally gay.
Conspicuously there is no mention of how much mass Erff gains from asteroids and meteorites?
Have you ever been outside and noticed little white ashes and big dust particles suddenly fall in front of you? Those are very small meteor(ites). They add thousands of tons of mass to our little insignificant space rock from outside our closed system all the time and always have, just the way gravity intended it to be.
31.5 inches out of plumb in over 67,130,000 feet not even a rounding error.
What do they mean “it shouldn’t have happened”? What makes them even consider that?
That’s the first thing I thought of, 3 Gorge Dam Damn that damn
Naw, plate tectonics wouldn’t have anything do with it. Or active volcanoes like Kilauea, or travelling through our Galaxy at over a 1/2 million mph. The list is long of other attributes that may alter the position of mass of Earth.
How about the uncountable tons of space junk we put there, that mass is no longer physically on our planet. Or weathering of mountains that would lower the center of gravity, or the dams built by the Chicoms or the empty ones in CA.
Someone is working on getting grant money...
Trust the Science (TM)!
Guam is in big trouble then.
No wonder I’ve had trouble keeping my balance lately.
The Milankovitch Cycle:
https://www.gi.alaska.edu/alaska-science-forum/wanderings-arctic-circle
Holy crap, if we can send about 11 million +/- illegals to Guam, the island should tip back in the opposite direction and provide a functioning counterweight to the earth’s altered rotation.
Kind of like putting lead weights on an unbalanced tire.
The Earth’s crust on average around 1% of the total volume of the Earth. The ground water content would probably be less than 1% of that volume. The volume of ground water pumped out of the crust is probably less than 1% of the total. So somehow 0.0001% disruption of the Earth’ volume has caused a dramatic shift? Also this only counts volume not mass, the core of the Earth is a solid ball of nickel and iron.
Just STFU about crap that doesn’t even matter. And that is if I even believe you (scientists)
Uranus has the most extreme axial tilt in the solar system, measuring approximately 97.77° (often rounded to 98° or described as 82.23° depending on the pole definition). This orientation causes the planet to rotate on its side, with its axis nearly parallel to the plane of the solar system.
This unique tilt results in the most extreme seasons of any planet, where each pole experiences roughly 42 years of continuous sunlight followed by 42 years of continuous darkness during its 84-Earth-year orbit.
Can we fix it? Remember in the 1970s was a plan to mine coal grind it to dust and spread it on the Ice fields to increase absorption from the sun to stop THE COMING ICE AGE!
Then not long back was a plan to place sheets in outer space and stop the sun from Global Warming!
Now this tom foolery.
Reminds me of the movie I am watching right now. THE CRACK IN THE WORLD(1965)
https://www.youtube.com/watch?v=a6kyLbicKaM
I HAVE IT ON DVD. SAW IT WAY BACK THEN. GOOD MOVIE!
Wait until they find out what is really coming due to the magnetic pole shift that is happening.
Same difference
That went over a lot of heads
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