Earth Has Tilted 31.5 Inches. That Shouldn't Happen
79 comments
·July 26, 2025x______________
throwaway150
> https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL10...
Any chance the original link can be replaced with this? This is definitely way more informative than the clickbait article.
panarchy
But this implies it could be the fault of human influence. Humans are incapable of making any sort of change to the planet! That would be inconvenient.
mr_toad
Don’t look down!
panarchy
But that's where all the sand is to put my head into!
ForOldHack
Down? Or down under?
ForOldHack
To everyone to posts links to the source material: THANK YOU SO MUCH! Thank you.
shvdle
[flagged]
perching_aix
I understand that this is ragebait, but even then, these are not mutually exclusive claims. There being a significant contributor doesn't mean it was the dominant contributor, and you being told things by some people doesn't mean you're choosing your sources well / the same as others.
Mutual exclusivity not applying so much so, that the article you're commenting on downright puts these events into the following hierarchy: groundwater pumping -> climate change -> sea level change. So it'd be a subset of the total effect of it on a theoretical pie chart: literally no conflict in the rhetoric.
kubb
Sigh. You made an account for this?
Do you know what a contributor is?
I understand if someone with cognitive issues buys into demonstrable fact denial, but hackers usually are way above that level.
asacrowflies
The amount of fact denial and anti science comments on this site are much higher than reddit or others honestly.... Just has moderation to not allow shitposts and gifs and such but it is still very eloquent science illiteracy.
shvdle
[flagged]
oh_nice_marmot
The melting of ice caps, glaciers and others make no difference then.
0hijinks
>> ...we can see that, in less than two decades, Earth has tilted 31.5 inches as a result of pumping groundwater. This equates to .24 inches of sea level rise.
For those confused how they managed that geometric analysis, the sea level rise mentioned in the paper [1] is caused by groundwater depletion. The tilt is caused by groundwater depletion. The sea level rise is not caused by the tilt.
[1] https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL10...
martinpw
Figure 1 in the above paper packs a lot of interesting information: https://agupubs.onlinelibrary.wiley.com/cms/asset/d7c477fa-3...
One important factor shown there is that dams hold back water on land, so act to decrease sea levels. It is not as big an effect as groundwater depletion, but is significant (around half as much).
The net effect of these two is much less than the other factors causing sea level rise (melting land ice) - looks like around 10% of total sea level rise comes from groundwater depletion+dams combined.
metalman
here's the problem with dams filling up and offseting ocean rise, amost all of the potential large dams, have been built and are full now, and that offset has masked some ocean rise, which is now accelerating, but all of the "planning" ,climate mitigation policy, treatys, etcerlalala, has been working with the wrong numbers. the wild card is changes in salinity and temperature shutting down the main thermo transfer currents at each pole, setting off deap ocean warming and expansion. not good.
chongli
Not to mention that inches are not a measure of angle, they’re a measure of length. I would prefer a proper measure of angle such as arcseconds. With some dirty math (taking 31.5 inches as an arc segment of earth’s polar circumference) yields a tilt of roughly 4 milliarcseconds, an extremely small angle to say the least.
jacobolus
An arcsecond is 1/60 of an arcminute; an arcminute is 1/60 of a degree (°); a degree is 1/360 of a full turn. A "milliarcsecond" is probably an unfamiliar unit (an angle so slight will only be used in extremely specialized contexts), so if you like you could decimalize this to an angle of 0.000001°.
The measure of distance on earth is probably more easily comprehended by almost everyone though.
dotancohen
> The measure of distance on earth is probably more easily comprehended by almost everyone though.
ForOldHack
Although I hate/detest using AI, I asked Google to calculate it...
0.0000072 degrees is 25.92 milliarcsecond.
Assuming that the Earth is a perfect sphere, which it is not, so now...
I have to burn up some Mathematica time, and have it calculated in elliptical coordinates.
null
skeledrew
I, and I suspect many others, have no clue what an arcsecond is and thus it's significance in anything. Inches also doesn't really give accurate significance, but at least it's relatable and doesn't leave me 100% lost, and I can focus on the message that something significant has been discovered, which may require some action.
SoftTalker
I think it's pretty apparent that ~1 yard, i.e. about one step at a typical walking stride, is tiny relative to the circumference of the earth. I agree that it's a more understandable measure for most people than "arcseconds"
grg0
What happened to degrees or radians?
rayiner
Sigh. This is why I read the comments. Thank you.
stouset
So just to clarify, what you’re saying is that the volume of water we’ve pumped is directly responsible for the observed sea level rise? The article makes it sound as if the tilt is what was responsible, and I was curious about the mechanics of that.
SoftTalker
Why shouldn't it happen?
I would guess that when there were gigatons of frozen water where there now is none that also changed the rotation of the earth.
Large magma flows and volcanic eruptions also change the rotation.
The earth is not a static system.
bbuut
To most people it is a static system as they live life based on the Gregorian calendar, and that loop, and never look into the dynamism in nature.
Headlines like this are not intended to be hard science.
They’re intended to connect to most people’s beliefs. Usually they explain away the knee jerk false beliefs.
eastbound
There is also a theory that the gravity made by the icecaps attracts water north and south. After melting, Sweden would see the water go down by 8 meters, the median point would be the south of England, and oceans would rise twice more around the equator.
OJFord
As we've already observed sea level rising, wouldn't we have also already observed it falling in Sweden (and rising faster around the equator) if that were the case?
pixl97
Well you also have to take isostatic rebound into account when attempting to calculate this as the crust where the glaciers were is still rising.
https://www.antarcticglaciers.org/glaciers-and-climate/sea-l...
eastbound
We absolutely have. Remember NYC was supposed to be underwater by 2000. That’s probably because of counter forces like this one. This, or the prediction was a scientific mistake. They happen, too.
nothrowaways
> Planet Earth Has Tilted 31.5 Inches
How much would that be in degrees?
throwaway_95283
0.00000718742 degrees = 31.5 inches / 40,075 km * 360 or 0.000451599142 arcseconds obviously its not very much,
ForOldHack
Can you check your units? in/km? 31.5" is almost exactly 0.8m
droopybuns
Cargo cultist stem aficionados write sentences like “Can we fix it back?”
owenversteeg
Obviously we can, global groundwater depletion is very hard to estimate but estimates range from 20-300 km3/year (this paper uses a figure of 126.) Global desalination production is around 35 km3/year and growing rapidly.
1km3 water =1 gigaton = 1B m3 water.
thayne
> I’m concerned and surprised to see that pumping groundwater is another source of sea-level rise
How is that surprising? It seems pretty obvious to me that pumping groundwater would accelerate how quickly that water ends up in the ocean, and could thus lead to rising sea levels.
rNULLED
i myself personally must untilt the world 31.5 inches
readthenotes1
Glueing yourself to a heavily traveled road should do it
csense
Start with a spinning sphere with a known axis / rate of rotation and some bit of mass on its surface that you can move. You can move it in three directions, let's call them latitude, longitude and altitude [1]. The classic examples I learned in physics class are about altitude (e.g. figure skater spinning faster when she brings her arms inward) which alters the magnitude of angular velocity (assuming conservation of angular momentum).
My intuition is that, if changing the altitude only affects the magnitude of the angular velocity, the other 2 degrees of freedom (longitude and altitude) must determine the direction of the angular velocity.
You start with a model of mass distribution of Earth over time, let us say M(x, y, z, t). Let us call w(t) the Earth's angular velocity at time t. If you know w(t_0) for some time t_0, you can calculate what the model says w(t) will be. The givens are: M(x, y, z, t_0), M(x, y, z, t), w(t_0), and conservation of angular momentum. You want to calculate w(t) from the model, then compare that calculation to the measurement to test the model. Your hypothesis is the model is accurate; your experiment is comparing the model's prediction of w(t) against the measured w(t).
I'm immensely curious to know how M(x, y, z, t) is calculated. They show some satellite images but it seems like they would only measure lakes, rivers, and maybe surface level soil saturation. But to me "groundwater" implies things like aquifers and underground storage, how do they measure that? You'd need to not only know the amount of water but also its change in latitude and longitude. Do you assume that if groundwater is used it ends up in the oceans? That seems a bit presumptuous, wouldn't a lot of it soak into the ground, get taken up by plants, find its way back down into an aquifer, etc.? Having water soak into the soil and become integrated into a plant is literally the point of watering crops, if we assume agricultural water ends up in the ocean doesn't that mean farmers are using too much water, which would be economically irrational because water is not free?
For that matter, why focus so much on water? Solid matter also has mass and we change its latitude, longitude and altitude when we mine it and turn it into products that we ship all over the world. For that matter, people and cars and ships and airplanes and wild animals all have mass and move around every day.
I'm a bit lost trying to follow the paper, it says "Changes in terrestrial water and oceanic mass loads were converted to spherical harmonic (SH) coefficients of the geoid..." but I only have a vague notion of what spherical harmonics are, and I don't really understand the given formulas.
[1] Latitude: Along the surface in the direction it's spinning. Longitude: Along the surface parallel to the axis of rotation. Altitude: Toward or away from the center of the sphere.
mvdtnz
How do you "tilt" in inches? A tilt is a rotation. I won't read an article with a headline that not only measures a tilt in the wrong type of unit but also opts for a medieval variant of a distance measure.
desireco42
All that K-Pop makes people jump too much
aaron695
[dead]
smitty1e
I, for one, appreciate the defiance of SI. #FightThePower
Clickbait title.
Link to the original study:
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL10...