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Earth NASA Science

Humans Are Causing the Earth To Wobble More Than It Should, NASA Finds (bgr.com) 205

Posted by BeauHD from the finger-pointing dept.
A reader shares a report from BGR: When looking at the Earth from afar it appears to be a perfect sphere, but that actually isn't the case. Because Earth isn't uniform on all sides due to land masses that shift and change over time, our planet actually wobbles a bit when it spins. Now, a new study by researchers with NASA's Jet Propulsion Laboratory and several universities and science centers has pinpointed the causes of Earth's imperfect spin, called "polar motion," and they found that humans are contributing to it. The researchers used a wealth of data gathered over 100 years to build mathematical models to trace the causes of the wobble and found that three factors are at play, and mankind is responsible for one of them. Two of the three factors identified by the scientists are glacial rebound and mantle convection. Glacial rebound happens when thick ice sheets physically push down on land masses, compressing them, but then release that pressure upon melting. The land then balloons back up over time, causing Earth's spin to wobble as if slightly off-axis. The effects of the last ice age, which would have compressed a huge amount of land across many continents, is still being felt today in the form of glacial rebound.

Mantle convection, the other uncontrollable factor in Earth's wobble, relates to our planet's inner workings. The plates on Earth's surface are in constant flux due to the movement of liquid rock far beneath our feet. The researchers believe these currents also contribute to the planet's imperfect spin. The third and final factor identified by the scientists is the massive loss of ice on Greenland and other areas, which is the direct result of global warming thanks to human activities. The researchers estimate that Greenland has lost roughly 7,500 gigatons, or 7,500,000,000,000 metric tons of ice due to global warming. All that ice loss has happened in the 20th century, and greenhouse gas production has been cited as the primary culprit. Losing all that mass has caused a significant shift on the planet and has contributed to the wobble as well.
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Humans Are Causing the Earth To Wobble More Than It Should, NASA Finds More

Humans Are Causing the Earth To Wobble More Than It Should, NASA Finds

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  • Not That Far (Score:3)

    by Baby Duck ( 176251 ) on Tuesday September 25, 2018 @10:16PM (#57376776) Homepage

    The plates on Earth's surface are in constant flux due to the movement of liquid rock far beneath our feet.

    In terms of the Earth's radius, the liquid rock is not that far. It's close. It's so close. So scarily, scarily close!

    • Yeah.. We only have to dig 3000 km to arrive at liquid rock. That's like 0.0001% of Earth's ~6000 km radius. Right?

      • Re: (Score:2)

        by rtb61 ( 674572 )

        The living proof, that a little bit of knowledge is often more dangerous than none, "Two main zones are distinguished in the upper mantle: the inner asthenosphere composed of plastic flowing rock of varying thickness, on average about 200 km thick, and the lowermost part of the lithosphere composed of rigid rock about 50 to 120 km thick. A thin crust, the upper part of the lithosphere, surrounds the mantle and is about 5 to 75 km thick." (https://en.wikipedia.org/wiki/Mantle_(geology), I edited out the impe

      • Sometimes we don't have to dig at all. There are places where the liquid rock comes right up to the surface all by itself.

  • Guam (Score:3)

    by Alypius ( 3606369 ) on Tuesday September 25, 2018 @10:26PM (#57376814)
    Sounds like Rep. Johnson was on (to) something! [snopes.com]
  • "Wobble" implies some sort of cyclic shift of the Earth's geographic axis. But they seem to be describing a simple change.

    Interestingly, searching for a map showing any such change to the geographic pole produces, well, not much. It seems to be all about the magnetic pole.

    • I have observed that when you put a heavy solid object on a spinning object, such as a washing machine, it throws it off balance and makes it wobble.

      I have also observed that if the washing machine is full of water, in the spin cycle the water self- balances. It's not off balance and doesn't wobble because the water automatically centers around the center of the spin.

      Helicopter rotors use the same effect to self-balance, allowing each blade to move a bit relative to the others. When they can move, they self

  • Contradiction (Score:1, Insightful)

    by ichthus ( 72442 )

    The effects of the last ice age, which would have compressed a huge amount of land across many continents, is still being felt today in the form of glacial rebound....
    {snip}
    The third and final factor identified by the scientists is ... the direct result of global warming thanks to human activities.

    So... acknowledgment that we're still coming out of the last ice age (you know, warming), but (and in the very next breath, mind you) blaming (in its entirety) this warming solely on human activity. How fucking

    • Re:Contradiction (Score:5, Insightful)

      by Plus1Entropy ( 4481723 ) on Wednesday September 26, 2018 @12:10AM (#57377144)

      They are speaking of 2 different effects, both caused by the melting of ice.

      The first effect is due to how the land responds to the ice melting. This continues long after the ice has melted, because the land does not decompress instantly. This is not (really) about glaciers that are melting today, the land is rebounding from glaciers which melted millennia ago.

      The second effect is due simply to the loss of the ice itself. As stated in TFS, the 7500Gtons is only over the last 100 years. That much mass loss in a fairly localized area was enough to make a significant contribution to the movement of Earth's center of mass, impacting the wobble.

      Finally, it's not the direction so much as the rate. Yes, we're coming out of an ice age, so we would expect average temperatures to gradually climb. However, what we have seen is that the climb has accelerated. Specifically, it has accelerated during the time that we have become industrialized. That acceleration means that certain effects will be more extreme, and we will have less time to adapt or prepare for them.

      This is not just true of the climate, but of any non-linear dynamic system (aka everything). When a system moves from one state to another, there are high frequency effects introduced. The faster the system transitions, the more pronounced those effects are.

    • Well, that question is easily answered: you just acknowledged that you are extremely stupid.
      HINT: the ice age is over since 15,000 years.

      • Re: (Score:2)

        by ichthus ( 72442 )

        HINT: the ice age is over since 15,000 years.

        Then, why do they state that the earth is still coming out of the ice age? Yeah, they say it -- it's right there in my first post, copied directly from the summary, moron.

        • Then, why do they state that the earth is still coming out of the ice age? Yeah, they say it -- it's right there in my first post, copied directly from the summary, moron.

          They don't. The sentence you quoted says that the land is still rebounding after the glaciers melted, not that the temperature would still be rising without human contribution. Glaciers don't reappear the moment that global temperature begins to drop.

        • why do they state that the earth is still coming out of the ice age?

          Why didn't you respond to my reply [slashdot.org], where I explain exactly why you misunderstood what the article was saying?

          Of course, you don't have to be convinced by my comment, but at least we could continue the discussion.

          Unless you just comment because you like hearing the sound of your own voice (so to speak)?

      • Re: (Score:2)

        by jbengt ( 874751 )
        To be pedantic, the latest glaciation retreated 15,000 years ago.
        We're still in an ice age (there's still permanent ice at the poles and on top of some mountains) and if we come out of the ice age, it will be getting significantly hotter than it has been in the last couple of million years or so.

        • Obviously the "article" misused "ice age" instead of using the more appropriated term "glacier period".

          Obviously, all on /. except you pedant, grasped that, and continued to use the lay man term: "ice age".

          But thanx for pointing it out. I forgot to write "ice age" in quotes, as I usually do to get rid of people like you.

    • Comment removed based on user account deletion

      • The global warming scientists and politicians are not to be trusted.

        In general scientists are among the most trustworthy of human beings. That's because they spend so much time and effort keeping each other honest. In order to believe that climate scientists are not being honest about their findings you would have to believe thousands of them have been involved in a decades long conspiracy that no one's been able to crack. Given the amount of opposition to them it's just not believable to me that if there were a substantial problem with their work it would not have surfa

    • So... acknowledgment that we're still coming out of the last ice age (you know, warming), but (and in the very next breath, mind you) blaming (in its entirety) this warming solely on human activity. How fucking stupid do they think we are? ...

      Actually we finished coming out of the last glacial period (ice age) around 8,000 years ago and had slowly started dropping toward the next one as the temperature has been on a slight downward trend since then. But the massive increase in greenhouse gases in the atmosphere, primarily due to human emissions has reversed that trend.

  • are the high levels of obesity in the US causing the wobble?

  • Yo Mamma (Score:2, Insightful)

    by alvinrod ( 889928 )
    Yo mamma so fat, she makes the earth wobble more than it should.

    We all know that's the real cause.

    • Yo mamma so fat, she makes the earth wobble more than it should.

      That's nothing, your mom is so fat she has smaller fat women orbiting her.

  • Be wary of weasel words like 'contributes to' because they can be misleading yet technically correct (not always the best kind). In particular, if a contributor is responsible for a negligible portion.

  • Just have like everyone in China jump up and down at the same time for a while. If the wobble gets worse, have everyone in North America jump up and down for a longer period of time.

  • Losing all that mass??? (Score:2, Informative)

    by mark-t ( 151149 )

    What, did it escape into space or something?

    Because otherwise, regardless of its form, all of that mass is still here, on earth.

    Seriously.... the principles of conservation of matter and energy is like grade 5 or 6 science class stuff.

  • Strange (Score:3)

    by hcs_$reboot ( 1536101 ) on Wednesday September 26, 2018 @01:20AM (#57377280)
    "The third and final factor identified by the scientists is the massive loss of ice on Greenland and other areas"
    That affecting the "wobbling" is possible. But the loss of ice - melting and going into oceans - should make earth wobble less, as oceans are more equally distributed on earth than blocks of ice.

    • You have a rotating mass.
      You distribute some mass from some point to another.
      Obviously this causes wobbling, until the "system has settled".

      The fact that the mass is now more even distributed, does not change the fact that it takes quite a time until the wobbling ceases.

  • I blame this "double-step" music that's apparently all the rage nowadays - it's known for its "wobble".

  • Popcorn time! (Score:2, Insightful)

    by Opportunist ( 166417 )

    Get out your bag of popcorn folks and grab a soda, the astroturfers are on stage again! What are they gonna give us today? "It's not man made"? "It doensn't happen"? Or are we going to be entertained by a new conspiracy theory around the evil scientist that gets rich from wanting to change our way of life?

    Anyhow, we know it's gonna be a blast! Let the show begin!

    • I wish I was an astroturfer. I'd love to get paid by the DNC or GOP to post on forums.

      But no, I'm just an ordinary guy, who gets paid Nothing for being on /. forum. TRIVIAL: There have been 5 ice ages on the earth, including the one we are experiencing now.

      - The earth has spent the majority of its time (90% of its life) with NO ice on the poles. This is called a Tropical Age.

      • - The earth has spent the majority of its time (90% of its life) with NO ice on the poles. This is called a Tropical Age.

        True. You know what else the Earth didn't have during those times? Humans.

      • Comment removed based on user account deletion

  • Easy fix (Score:3)

    by LordHighExecutioner ( 4245243 ) on Wednesday September 26, 2018 @05:01AM (#57377726)
    we just need a coordinated effort [wikipedia.org] among all the people in the world.
  • Comment removed based on user account deletion

  • What happened before the ice??? (Score:3)

    by acoustix ( 123925 ) on Wednesday September 26, 2018 @08:53AM (#57378278)

    Did the Earth wobble more before the ice age compacted the surface? What's the correct amount of wobble? What's the best temperature for the planet? Who gets to decide all of this?

    • Did the Earth wobble more before the ice age compacted the surface?

      We don't know.

      What's the correct amount of wobble?

      We don't know.

      What's the best temperature for the planet?

      We don't know.

      Who gets to decide all of this?

      We'll require more grants to study these questions, and get back with you on that.

  • Glacial rebound means the Crust is rising, as a result land will rebound higher than current sea level leaving plenty of room for all the melted ice. Such immaculate design!

    Joke aside, have the Global Warming "scientists" taken into account glacial rebound with relation to their flood models?

  • "...The third and final factor identified by the scientists is the massive loss of ice on Greenland and other areas, which is the direct result of global warming thanks to human activities...."

    Yes, no begged questions there at ALL.

    Perhaps the title could have been better formed as "Since we're all believing that THIS spike in temps - comparable in frequency and size to the last 20 times this has happened over the previous 3 million years - happens to be caused by humans, we're going to blame everything on h

  • Al Gore reported yesterday that the dangers of global wobble were now dire, with the danger of Earth whirling out of its orbit and falling in to the sun becoming more and more likely. Human activity is entirely responsible for this situation and the only cure for it is enormous taxes on the developed nations, who move around more than the rest of the world and, of course, have lots of money. Gore has formed a wobble bank that will be selling wobble credits to rich people so that they can assuage their con

  • "Glacial rebound"...

    "Mantle convection"...

    "massive loss of ice on Greenland and other areas"...

    That's two causes. Two.

  • Is there anything they can't or didn't do?

  • Kim Kardashian's ass for the wobble.

  • Climate change has become like a bad "as seen on tv" product where some coked up asshat just keeps adding on to the pile of worthless nonsense with another "but wait, there's more". Next they'll tell us climate change is responsible for Bill Cosby raping women.
  • "I am certain that the world is hurtling ever closer to the Sun, overbalanced as it is on one side by the overbreeding of the fecund Hindoo, but at present there is little I can do about it." ( https://www.theonion.com/my-su... [theonion.com] )
  • Another one not mentioned is the massive weight of water for when we create MASSIVE dams such as 3 gorges, Kariba Dam, Bratsk Dam, etc. In fact, the biggest ones have had plenty of earthquakes associated with them.

  • The ice sheet on Greenland is, on average 7,005 ft thick. Greenland's ice sheet is 660,000 sq miles. Ice weighs 57.3 lbs/ft^3. A back of the envelope calculation shows that the 1.5 X 10^16 lbs of ice mentioned in the article amounts to about 2.62 X 10^14 cubic feet of ice, or a cube 63,970 feet on a side. Or, 4,092,160,900 sq ft X 9.13 = 37,369,811,959 sq ft, or 1,340 sq mi.

    0.20% of the total ice covering Greenland.

    WWII fighter aircraft crash landing on Iceland were found 46 years later buried 260

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