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Earth Has Tilted 31.5 Inches. That Shouldn't Happen
- 0hijinks 1y ago>> ...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/10.1029/2023GL103509 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL10...
- chongli 1y agoNot 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.
- rayiner 1y agoSigh. This is why I read the comments. Thank you.
- skeledrew 1y agoI, 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 1y agoI 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 1y agoWhat happened to degrees or radians?
- fiddlerwoaroof 1y agoA degree is too big for the effect, the division of the degree into 60 arcminutes and the arcminute into 60 arcseconds is the standard subdivision of degrees as an angle measurement going back to the Sumerians.
- skeledrew 1y agoStill doesn't say much to many. Temperature will be what comes to mind first for the lay person when they hear "degree", blank stare for "radian". But pretty much everyone in the US knows what an "inch" is, and the rest of the world can do a quick lookup/conversion. And everyone knows immediately on seeing the headline that something moved from its usual spot to somewhere else.
- ForOldHack 1y agoAgain... AI blows, but ... "Calculate the fraction of the circumference represented by the arc segment:Divide the arc segment length by the Earth's polar circumference (in inches):31.5 inches / 1,574,896,558.4 inches = 0.0000000200012759 Radians. Which is kinda interesting, as it calculates the earths' circumference in Inches. 1.57 Billion inches.
- johnisgood 1y agoI would still have been lost as I use the metric system. Just use whatever is most accurate, and I will research it.
- skeledrew 1y agoThe site is US-based, and thus caters primarily to the US "lay person" first.
- jacobolus 1y agoAn 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 1y ago> The measure of distance on earth is probably more easily comprehended by almost everyone though. The measurement itself is useless without knowing the size of the Earth, which very few people know offhand. That said, 30 inches sounds like something tangible, and that's the important information here. That human activity had a measurable, tangible effect on the Earth.
- ForOldHack 1y agoAlthough 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.
- deleted 1y ago[deleted]
- jacquesm 1y agoOn a very large and massive object unexpected changes of such magnitude may be a 'small angle' but they still require so much energy that an explanation is warranted.
- stouset 1y agoSo 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.
- martinpw 1y agoFigure 1 in the above paper packs a lot of interesting information: https://agupubs.onlinelibrary.wiley.com/cms/asset/d7c477fa-3353-4f9f-b7c2-264a33f5e1a0/grl65897-fig-0001-m.jpg 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 1y agohere'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.
- x______________ 1y agoClickbait title. Link to the original study: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL103509 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL10... Drift of Earth's Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993–2010
- shvdle 1y ago[flagged]
- oh_nice_marmot 1y agoThe melting of ice caps, glaciers and others make no difference then.
- kubb 1y agoSigh. 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.
- shvdle 1y ago[flagged]
- righthand 1y agoGlobal warming already has multiple contributors…so always.
- asacrowflies 1y agoThe 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.
- perching_aix 1y ago
- muzani 1y agoIt always surprises me how millions of planets can move about predictably for millions of years. Unless it's hit with some gigantic rock... or it gets infected with sentient life.
- riku_iki 1y agoits survival bias, they were moving billions of years before, objects with unstable orbits traveled somewhere else, and stable objects formed stable planets.
- positus 1y agoHumanity is not an infection. And how many of those millions of planets can you name?
- AIPedant 1y agoI would not draw that conclusion from this article - we don't have such fine-grained data from other planets, perhaps their axes are more wobbly than Earth's. E.g it was only in 2020 that we discovered Mars has a "Chandler wobble" similar to Earth's (which was discovered 150 years earlier). But Mars's wobble is quite different as a matter of geophysics, Earth's Chandler wobble is mostly sustained by ocean sloshing. There's a whole lot we don't know about the non-Earth planets. I will add that human extraction of groundwater it not nearly as impactful as the formation of large igneous provinces and other ancient supervolcanoes. A tectonically active planet will definitely wobble unpredictably.
- PartiallyTyped 1y agoWe also found that our dams have slowed earth’s rotation!
- furyofantares 1y ago> or it gets infected with sentient life. If only more planets could be so lucky. What value does a planet have without sentient life there to enjoy it?
- SoftTalker 1y agoWhy 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 1y agoTo 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 1y agoThere 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 1y agoAs 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 1y agoWell 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-level-rise-2/recovering-from-an-ice-age/#SECTION_3 https://www.antarcticglaciers.org/glaciers-and-climate/sea-l...
- eastbound 1y agoWe 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.
- mistermegabyte 1y agoThe earth will be fine. I'm sure during the ice ages with gigatons of water trapped on the surface in glacial ice it would have had to changed the tilt also and the planet survived. The earth is such a large and variable system that over the long term, humans can't significantly permantly change something like weight distribution.
- andrepd 1y agoWell yeah, it's never really about "save the earth", it's more precisely about "save ourselves by saving an earth that is habitable by humans".
- nlitened 1y agoHumans are literally one of the most adaptive creatures on this planet though
- throw123xz 1y agoAnd even the most adaptive creatures have limits.
- drdaeman 1y agoHuman intellectual/cognitive capabilities are unprecedented, though. I'm not sure if we'll live to see it, but I'd be pretty surprised if some fine day humanity won't evolve enough to abandon the primate bodies and decouple humanity from its biology. That is, I believe we'll eventually give birth to thinking machines, and hopefully they'll keep the humanity going even if other branches would possibly fail to the environmental changes. Unless, of course, we won't make ourselves extinct first.
- vlovich123 1y agoBy what metric? Humans have been around for what, 600k years? That’s genetically. Behaviorally (abstract reasoning, complex language) is only believed to be about 100k years old. Primates as a branch are only about 65m yold. Crocodiles are 200m yold (mostly unchanging) while birds are 150m (wild diversity). By whatever metric, humanity has no claim to adaptability as a species because we’re really quite too new on the scene. At best we’re more a virus - came on quick but spread at unprecedented rates all across the world bringing ecological destruction with us. We have yet to see if we can survive the Earth’s immune response.
- nothrowaways 1y agoThis doesn't make sense, it's like taking a spoon full of water from a barrel. Shouldn't affect anything.
- ceejayoz 1y agoIt’s 31 inches in a planet that’s about 500 million inches wide. Would you notice that proportion of a change in a standard sized barrel?
- ForOldHack 1y agoIf you take a basketball, and breathe on it, the frost collected on it, is less than the thickness of the atmosphere. Many phenomenon are even less detectable, but see the prior comment about 747s.
- ceejayoz 1y agoYeah. Or parts-per-million of polonium in tea. Our ability to perceive it is different from our ability to be affected by it.
- stouset 1y ago“This doesn’t make sense. We’ve only added 200ppm of CO2 to our atmosphere. Shouldn’t affect anything.” Systems at a roughly stable equilibrium can be surprisingly easy to shift out of that equilibrium by pushing them ever so slightly outside a local minima. Nobody right now is saying this particular situation is going to result in catastrophe, but we should exercise some caution when we are causing observable effects to the one planet we inhabit.
- nothrowaways 1y agoI can bet the missiles and space rockets we launch have a higher effect to unbalance planet Earth's equilibrium.
- 1y ago
- nothrowaways 1y ago> Planet Earth Has Tilted 31.5 Inches How much would that be in degrees?
- throwaway_95283 1y ago0.00000718742 degrees = 31.5 inches / 40,075 km * 360 or 0.000451599142 arcseconds obviously its not very much,
- ForOldHack 1y agoCan you check your units? in/km? 31.5" is almost exactly 0.8m
- _1tem 1y agoSo is it possible that Earth keeps “tilting” until the rotation direction is effectively reserved and the Sun rises from the west?
- gpm 1y agoConservation of angular momentum says no. Short of some giant external force acting on it (e.g. a collision with an exoplanet)
- aaron695 1y ago[dead]
- droopybuns 1y agoCargo cultist stem aficionados write sentences like “Can we fix it back?”
- owenversteeg 1y agoObviously 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.
- pivo 1y agoThe op was referring to the highly ungrammatical sentence, "Can we fix it back", not the possibility of fixing the tilt.
- desireco42 1y agoAll that K-Pop makes people jump too much
- mvdtnz 1y agoHow 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.
- thayne 1y ago> 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.
- smitty1e 1y agoI, for one, appreciate the defiance of SI. #FightThePower
- csense 1y agoStart 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.
- rNULLED 1y agoi myself personally must untilt the world 31.5 inches
- readthenotes1 1y ago[flagged]