Forgot your password?
typodupeerror
Earth Science

Chilean Earthquake Shortened Earth's Day 374

Posted by kdawson
from the ice-skater-effect dept.
ailnlv writes "Days on Earth just got shorter. The recent earthquake in Chile shifted the planet's axis by about 8 cm and shortened days by 1.26 microseconds 'The changes can be modeled, though they're difficult to detect physically given their small size. ... Some changes may be more obvious, and islands may have shifted. ... Santa Maria Island off the coast near Concepcion, Chile’s second-largest city, may have been raised 2 meters (6 feet) as a result of the latest quake ...'"
This discussion has been archived. No new comments can be posted.

Chilean Earthquake Shortened Earth's Day

Comments Filter:
  • Great! (Score:5, Funny)

    by MichaelSmith (789609) on Monday March 01, 2010 @11:30PM (#31326374) Homepage Journal

    I can go home a few microseconds early today.

  • by MSBob (307239)
    Given the axial shift will that have a measurable impact on the climate in a measurable way?
    • by larry bagina (561269) on Monday March 01, 2010 @11:34PM (#31326392) Journal
      either way, it's anthropogenic.
      • by Anonymous Coward on Monday March 01, 2010 @11:47PM (#31326476)

        I knew it! I blame the political party I'm not affiliated with.

      • by FooAtWFU (699187) on Tuesday March 02, 2010 @12:41AM (#31326812) Homepage

        You say this to make fun of the global warming debate, but theoretically it's not completely impossible that underground nuclear testing has something to do with the specifics of any earthquakes since the 1950s or so. Earthquakes are undoubtedly chaotic, and a series of megaton explosions underground might have shaken things a little and helped them get where they're going faster (temporarily).

        Mind you, I'm not claiming that's necessarily the case either (or even probably the case). Just that, much like a decent conspiracy theory, it's not entirely nonsense or outside the realm of possibility. (I'd guess that overall seismicity remains the same overall but chaotic effects will change the locations of, say, half the aftershocks next century.)

        USGS FAQ here [usgs.gov].

        • by butlerm (3112) on Tuesday March 02, 2010 @03:30AM (#31327476)

          theoretically it's not completely impossible that underground nuclear testing has something to do with the specifics of any earthquakes since the 1950s or so.

          No doubt. Theoretically, it is an absolute certainty that the migration of swallows to Capistrano has something to do with the specifics of every earthquake for centuries now.

        • Really hard to say, but you can see a nice table here [wikipedia.org], showing the relative size of nuclear bombs and earthquakes. The energy in an 8.8 earthquake is nearly a million times greater than Hiroshima's.
          • Re: (Score:3, Interesting)

            by natehoy (1608657)

            Right, but it only takes a single pebble to start an avalanche.

            Now, mind you, if a nuclear weapon ever did trigger an earthquake it would probably just be the trigger event, and the pressure would still have been there from the start. If anything, the nuclear weapon would cause the earthquake to happen sooner, thereby possibly reducing the severity of the eventual quake.

            Wow, I just had a brilliant idea. California is worried about the Next Big Quake, and the solution to their problem is so simple - let's

        • by dintech (998802) on Tuesday March 02, 2010 @04:30AM (#31327726)

          As you probably already know, there are loads of other more mundane ways to instigate an earthquake. This wired article [wired.com] is quite interesting. To summarise:

          Build a Dam
          Inject Liquid Into the Ground
          Mine a Lot of Coal
          Drill a Gusher Dry
          Create the World’s Biggest Building
        • by Aceticon (140883) on Tuesday March 02, 2010 @06:22AM (#31328212)

          In Chaos Theory, a small change to the inputs can cause large changes to the results.

          However the changes are just as likelly to go in one direction as they are to go in the opposite direction: the butterfly effect is just as likelly to result in a typhoon instead of clear weather as it is to result in clear weather instead of a typhoon.

          Also, small changes to inputs can cause small changes to the outputs or even no changes at all (that's why it's called Chaos Theory) - plenty of butterflies flutter-about with out creating typhoons ;)

          If indeed the system that underpins earthquakes is chaotic, underground nuclear tests are just as likelly to have brought forward quakes as they are to have delayed quakes as they are not not have had much effect at all - in fact, they're likelly to have done all of them.

    • by biryokumaru (822262) * <biryokumaru@gmail.com> on Monday March 01, 2010 @11:37PM (#31326412)
      Man, I checked out that pizza [aclu.org] link in your sig, and that is so cool! I wish the pizza place would be that good around here. I live in NYC and I can't even get them to leave their car to deliver pizza to my door, let alone all those other handy features they show there.
    • Re: (Score:2, Insightful)

      by sleeping143 (1523137)

      Just because a phenomenon is measurable doesn't mean it's significant.

    • by delinear (991444)
      I sincerely hope not, or the next big human endeavour will be blowing holes in fault lines to try and "fix" climate change. Although if they can manage to make it a few degrees warmer here in the UK while simultaneously lengthening the weekends by an extra day, I may reconsider my position.
  • by Subm (79417) on Monday March 01, 2010 @11:33PM (#31326390)
    Crap, I was going to post something funny, but now I'm 1.26 microseconds late. Sorry, I gotta run...
  • Now we just have to harness this, and we won't have to worry about low-lying coastal areas being swept away by flooding and rising oceans!
  • by Opportunist (166417) on Monday March 01, 2010 @11:38PM (#31326418)

    I mean, don't forget that a day only has 86,400 seconds (give or take...). One such quake doesn't really matter. A hundred won't. A million will start to matter. A billion definitly will.

    And of course, they don't happen every day but, well, a billion years ain't that long if you're a planet...

    • by Anonymous Coward on Tuesday March 02, 2010 @12:06AM (#31326592)

      The reason the day length changes is because the quake caused a net motion of mass toward the center of the planet. This reduces the moment of inertia, and because of conservation of momentum, the planet's rotation must speed up.

      If this happened repeatedly, it would mean that the density of the planet was increasing. That can't happen to any significant degree, because it would involve compression, which requires a source of energy (note -- I don't mean that the increased rotation is due to an energy input, just that it takes energy to compress a planet). Earthquakes just move energy around, they do not create it. So over long spans of time, earthquakes tend to increase the length of the day by about as much as they decrease it. It all depends on whether the net motion was toward the center of the earth or away from it.

      This is based on my knowledge of physics, but I am not a geologist, so there may be complicating factors I don't know about. However, I'm pretty sure that the planet's density cannot increase arbitrarily.

      • by rachit (163465)

        IANAG, but I would assume earthquakes tend to assist moving matter "downhill"

      • by pongo000 (97357) on Tuesday March 02, 2010 @08:11AM (#31328710)

        This is based on my knowledge of physics, but I am not a geologist, so there may be complicating factors I don't know about. However, I'm pretty sure that the planet's density cannot increase arbitrarily.

        What goes up must come down...in geology, it's called istosasy. It's sort of like gravitational equilibrium. What sinks in one place is usually offset by a height increase elsewhere. Over years, the small geologic events (and yes, the Chile earthquake is small when measured in geologic units) balance themselves out. I would not worry too much about the lost microsecond. We'll gain it back next year.

    • by tompaulco (629533) on Tuesday March 02, 2010 @12:31AM (#31326748) Homepage Journal
      A quick back of the hand calculation tells me that tidal friction is only two orders of magnitude less effect than this. So about 100 days of tidal friction is equal to this event.
    • Re: (Score:3, Interesting)

      by indi0144 (1264518)
      So what happens if instead of 100 8.3 eartquakes we have 10 @ 10.1?

      From wikipedia:

      >> Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; in terms of energy, each whole number increase corresponds to an increase of about 31.6 times the amount of energy released.<<

      This quake was 8.8 ram == 15.8 gigatons of TNT delivered
      The one (the comet impact) that owned the dinosaurs was 13.0 ram or 100 teratons of TNT

      And we
    • Re: (Score:3, Informative)

      by derGoldstein (1494129)

      a billion years ain't that long if you're a planet...

      Yes, it is [ucolick.org]. Our sun's lifespan is about 10 billion years, and it's half-way through. In other word, the solar system should be having its mid-life crisis now.

  • FFS! (Score:5, Funny)

    by Foobar of Borg (690622) on Monday March 01, 2010 @11:44PM (#31326462)
    Oh, for fuck's sake! I've got too much shit to do already! And now, I have 1.26 microseconds less to do it in??!! Scheisse! Of course, maybe I shouldn't post on slashdot. Maybe that would save more than 1.26 microseconds.
    • Re: (Score:3, Funny)

      by Anonymous Coward

      Seriously! Think of all the things you could do with all that time:

      - Make love to your wife
      - List all of Pat Robertson's positive traits
      - Use WinMo before freaking out and throwing your phone out the window

      C'mon people, this is valuable time here!

    • Re:FFS! (Score:5, Funny)

      by feepness (543479) on Monday March 01, 2010 @11:55PM (#31326532) Homepage

      Oh, for fuck's sake! I've got too much shit to do already! And now, I have 1.26 microseconds less to do it in??!! Scheisse! Of course, maybe I shouldn't post on slashdot. Maybe that would save more than 1.26 microseconds.

      You could make love to your girlfriend a couple fewer times per week.

  • GPS affected? (Score:5, Interesting)

    by johnny cashed (590023) on Monday March 01, 2010 @11:49PM (#31326490) Homepage
    Does this affect GPS for a short time? I understand that the USAF (or whoever runs it) will correct the system, but how quickly does this occur? Would it affect a JDAM bomb in flight, for example?
    • Re:GPS affected? (Score:5, Insightful)

      by feepness (543479) on Monday March 01, 2010 @11:59PM (#31326558) Homepage
      If it was traveling at 400 miles per hour, 1.26 microseconds is 0.007 inches. I am assuming that is within detonation radius.
      • by Bigjeff5 (1143585)

        One would hope.

      • Re: (Score:3, Interesting)

        by Anonymous Coward

        It's not about the speed of the bomb. It's about the speed of the sattelites which orbit Earth and which the bomb uses to guide itself.

        A sattelite travelling in Geostationary orbit clocks 3.8km/s. In 1.26 microseconds it would travel about 5mm. If it, say, takes a month until the government calculates and issues the correcting commands, the offset would accumulate to 15cm.

        If a guided missile is launched to fly into a window of an enemy-occupied building, the offset can be enough to make a difference between

        • Re:GPS affected? (Score:5, Informative)

          by RoFLKOPTr (1294290) on Tuesday March 02, 2010 @01:44AM (#31327112)

          If a guided missile is launched to fly into a window of an enemy-occupied building, the offset can be enough to make a difference between hitting the window and hitting the wall.

          GPS doesn't have the kind of precision to guide a shot like that regardless of whether the time is uncalibrated. If we need to launch a missile into a building and it is imperative that it enter the building through a small window, we would surely use laser or thermal guidance... not GPS.

          • If a guided missile is launched to fly into a window of an enemy-occupied building, the offset can be enough to make a difference between hitting the window and hitting the wall.

            GPS doesn't have the kind of precision to guide a shot like that regardless of whether the time is uncalibrated. If we need to launch a missile into a building and it is imperative that it enter the building through a small window, we would surely use laser or thermal guidance... not GPS.

            The C/A code used by civilian GPS receivers d

        • by butlerm (3112)

          GPS satellites are in low earth orbit, and travel much faster than that, more like 300 km/s. Not that that makes much of a difference here. To first order, each satellite is going to continue on its merry way (i.e. be unaffected by the events on the surface), and the motion of a point on the earth's surface is going to move off of its expected track, in this case sped up by a factor of ~14 parts per trillion.

          The inertial velocity of the earth's surface at the equator is ~ 464 meters / second. So a fixed

          • by butlerm (3112)

            Correction: LEO satellites have an orbital velocity of approximately 7800 meters / second, or about 17,500 miles per hour.

      • by Anonymous Coward on Tuesday March 02, 2010 @12:16AM (#31326658)

        A James Bond inch? How awesome!

  • by zygotic mitosis (833691) on Tuesday March 02, 2010 @12:01AM (#31326570)
    Remember, this is only what a model predicts, unlike what the headline suggests. And anyway, I think even if the quake had effects on day length and/or axis, another quake somewhere else on Earth sets it back a little. It averages out to what we witness. Earth is a dynamic place.
  • by dmomo (256005) on Tuesday March 02, 2010 @12:14AM (#31326650) Homepage

    But according to my calculations, all we have to do is set our calendars back a day... ... in 188,253,750 (ish) years.

    I wonder how the PS3 will handle this.

  • by Korbeau (913903) on Tuesday March 02, 2010 @12:18AM (#31326678)

    People of Earth, at 18:00 GMT March 10 we all jump at the same time and regain our microsecond!

    • Re: (Score:2, Funny)

      by jdc18 (1654245)
      No no no, you just need the chinese to do it
      • by derGoldstein (1494129) on Tuesday March 02, 2010 @01:23AM (#31327020) Homepage
        I wonder... Compare the total weight of the entire chinese population to the total weight of the entire population of the US. Who's heavier?
        • by mjwx (966435)

          I wonder... Compare the total weight of the entire chinese population to the total weight of the entire population of the US. Who's heavier?

          If the US jumped a microsecond after China then the US would act as the wall and the earth would bounce into the opposite top corner pocket, haven't you ever played pool before.

          Signed

          Dave

  • i'm waiting for someone to link this quake to gloabl warming, or atleast some news reporter to ask the question.
  • Missed it by 1.26 microseconds. Damn.

  • “It’s what we call the ice-skater effect,” David Kerridge, head of Earth hazards and systems at the British Geological Survey in Edinburgh, said today in a telephone interview. “As the ice skater puts when she’s going around in a circle, and she pulls her arms in, she gets faster and faster. It’s the same idea with the Earth going around if you change the distribution of mass, the rotation rate changes.”

    No, it's not. It's called the "bored to death at the office and nobody's watching" effect. You spin your chair rapidly and lift your legs from the ground. Then put your arms out -- you'll slow down. Pull them back in -- you'll speed up.
    Also, "As the ice skater puts when she’s going around in a circle"? Did somebody miss a word there?

    Shoddy writing, bad analogies, this is an embarrassment.

  • The nanosecond the earth stood still.
  • The earth is naturally slowing down at a rate that makes this sort of thing hardly worth mentioning. That is why we have leap seconds.

    Several milliseconds (per year) total when every year we drift ~500 ms? A few thousand such earthquakes and we might be able to put off a leap second for another year.

    • by Animats (122034) on Tuesday March 02, 2010 @01:39AM (#31327094) Homepage

      The earth is naturally slowing down at a rate that makes this sort of thing hardly worth mentioning.

      Actually, the slowdown is only about 2ms/century, or about 0.054 microseconds/day. So a 1-microsecond jump in a day should be noticeable. This information is tracked. Here's the raw data from the Earth Rotation Service. [iers.org]

      With GPS systems working down to 15cm, changes like this get noticed.

      • by butlerm (3112)

        This 2 ms per century drift in the length of a day is an average. The actual variation [iers.org] is far more erratic - so erratic that this sort of thing seems rather likely to be lost in the noise.

        [By the way, clock drift here is the integral of the change in the length of the day per day. Hence the disparity.]

  • I had wondered why the shadow on my balcony tarp, which I use to mark seasonal progress, suddenly took a one-month JUMP shadow-wise. (about three inches)

    Holy fuck imagine if we had a 9.9 somewhere.

  • So does this mean atomic clocks aren't accurate anymore? Buahah glad I didn't purchase stock!!

  • by caywen (942955) on Tuesday March 02, 2010 @04:45AM (#31327776)

    I think if everyone in the world stands up and raises their arms for 10 seconds once per year, we can compensate for this.

  • Its Ok, (Score:5, Insightful)

    by Jarik C-Bol (894741) on Tuesday March 02, 2010 @08:19AM (#31328774)
    Its ok though, because it offset the effect of the three gorges dam in china, which made the days longer. http://www.theenergylibrary.com/node/11435 [theenergylibrary.com] sure, that dam lengthened the day by less than the earthquake shortened it, but we also have to account for other dams that have lengthened days.
  • by cenc (1310167) on Tuesday March 02, 2010 @02:43PM (#31334266) Homepage

    For us in the disaster zone (I am in Temuco 100 miles south of the worst hit areas), it feels like 48 hour days. They likly will just get longer as this goes on.

    if you want to help, visit http://www.allchile.net/ [allchile.net]

The more cordial the buyer's secretary, the greater the odds that the competition already has the order.

Working...