What The Earth Quake In Chile Caused

[Xyn]

My teacher told me yesturday in school that the earthquake was so wrong it actually disrupted the earths rotational force, making nights longer... Umm, im usually a science news junkie but havent come across any article like this yet.. Is this true? And if true, cannot this altar the earth alot more then we think? Edit: Chile, sorry.

[ChrissyMaria]

I read about that also, I'm not sure if its true but the force behind that quake could likely have slowed down the rotation by a thousanth of a second perhaps, not noticeable.

[SpecialInterests]

I heard that it altered the earth's axis. It would be so neglible that any difference would be imperceptible.

[nina]

"The quake shifted the earth of its axis by about 3 inches, shortening our days by 1.26 mega seconds. In addition, the quake set off a chain of strong aftershocks that are still being felt days later." (anyone know what a mega second is? lol)

[SpecialInterests]

I'm not quite sure how an earthquake can do this. I mean, an earthquake is an internal force. For every action there is an equal but opposite reaction. It would be like running a long a street and trying to slow yourself down by pushing on your own body with your hands. It wouldn't work cause your body pushes back with the same magnitude and there would be no resultant. Wouldn't there have to be some kind of external, unbalanced force to be able cause a net displacement? Is anyone able to answer this?

[nina]

1.26 mega seconds is 1.26×10^6 seconds. Which is 350 hours. It is supposed to be 1.26 micro seconds (1.26×10^(-6) seconds). lol @ 350 hours...that WOULD be a big deal

[ChrissyMaria]

That would be messed up and we would get night in am and day in pm and random cycles and all crops would die. That would be really messed up.

[juroara]

Wow! That's amazing and silly at the same time! And, I feel sorry for you that you can't edit your own title

[Xei]

"The quake shifted the earth of its axis by about 3 inches, shortening our days by 1.26 mega seconds. In addition, the quake set off a chain of strong aftershocks that are still being felt days later." (anyone know what a mega second is? lol) lol, whoever wrote this was spouting bullshit. Mega = 1,000,000. 'm not quite sure how an earthquake can do this. I mean, an earthquake is an internal force. For every action there is an equal but opposite reaction. It would be like running a long a street and trying to slow yourself down by pushing on your own body with your hands. It wouldn't work cause your body pushes back with the same magnitude and there would be no resultant. Wouldn't there have to be some kind of external, unbalanced force to be able cause a net displacement? Is anyone able to answer this? It's kinda possible. The Earth is actually slowing down all the time due to frictional forces. The energy released in the Earthquake could rid the Earth of some of its kinetic energy.

[nina]

And, I feel sorry for you that you can't edit your own title Fixed it. lol, whoever wrote this was spouting bullshit. Mega = 1,000,000. If you bothered to read on...you'd have see that I corrected it.

[Xei]

I guessed you were quoting from somewhere..? I was just saying that any source which makes such a ridiculous error isn't really reliable.

[Marvo]

I'm not quite sure how an earthquake can do this. I mean, an earthquake is an internal force. For every action there is an equal but opposite reaction. It would be like running a long a street and trying to slow yourself down by pushing on your own body with your hands. It wouldn't work cause your body pushes back with the same magnitude and there would be no resultant. Wouldn't there have to be some kind of external, unbalanced force to be able cause a net displacement? Is anyone able to answer this? If you're running and you suddenly swing your arm with all your force to the left, you will get knocked out of course. This is somewhat the same thing. A huge amount of mass suddenly shifts position, dragging whatever it's hanging on to with it.

[Xei]

Nah that's not physics to be honest. You'll be temporarily knocked off course but then you will have to bring your arm back to its original position and this will cause an equal and opposite change in your momentum. The only reason you might be permanently knocked off course is if you have sucky balance. A running person is far too complex an analogy to make with the Earth floating through space, because a running person has a variable frictional force with the ground which depends on all sorts of things.

[Invader]

Some of the mass of the Earth was shifted slightly away from the axis on which it rotates. In order for rotational momentum to be conserved, it would have to compensate by slowing down in order to make up for it's increased moment of inertia. The effect of course is marginal. Otherwise the Earth slows from the effect the moon has on our oceans. Our rotational momentum in that case is transferred to the moon's orbital momentum, which means that we slow down and the moon's orbit around the Earth gets longer.

[Xei]

Yeah I thought that could be an explanation too... didn't think the net effect of the Earthquake would have been a rise in the ground level tho.

[Invader]

The plate shifting North (towards the equator) would have had similar effect: The papers claim the decrease in length of day is attributed to an offset of our Earth's axis by several centimeters. I suppose shifting mass north or south would do that? Moving anything towards the equator would also increase moment of inertia anyways, no?

[Xei]

Do you say that because of the equatorial bulge? It seems intuitively right although would require some complex calculus to prove it, I think. How does the axis-shift explanation work?

[Invader]

How does the axis-shift explanation work? That I can't figure out yet. I got the axis bit from the following CNN article: The massive earthquake that struck Chile on Saturday may have shifted Earth's axis and created shorter days, scientists at NASA say. Although they don't explain why tilting the Earth more should slow it down any.

[nina]

From what I understand, they are not talking about the Earth's North South Axis around which it spins, but the Figure Axis which is the axis around which the Earth's mass is balanced. You guys may have already realized that, but I wasn't sure.

[Xei]

Hm, I suppose an increase in altitude of some mass would move the figure axis, though really the figure axis moving would really just be a byproduct and the moving mass would still be the causal factor.

[Xaqaria]

I'm not quite sure how an earthquake can do this. I mean, an earthquake is an internal force. For every action there is an equal but opposite reaction. It would be like running a long a street and trying to slow yourself down by pushing on your own body with your hands. It wouldn't work cause your body pushes back with the same magnitude and there would be no resultant. Wouldn't there have to be some kind of external, unbalanced force to be able cause a net displacement? Is anyone able to answer this? An earthquake is not similar to pushing on their own body with your hands. An earthquake releases energy from the earth. A better analogy would be running down the street and having your bones grind together in such a way that it produced a large amount of heat, and vibration. This Article was pretty informative.

[Spartiate]

Good info http://news.nationalgeographic.com/n...shortened-day/

[Xyn]

Thanks for article, glad to see this won't cause anything major. My first reaction was even a tiny change to the earth would become major. Glad to see it's not the case.

[SpecialInterests]

An earthquake is not similar to pushing on their own body with your hands. An earthquake releases energy from the earth. A better analogy would be running down the street and having your bones grind together in such a way that it produced a large amount of heat, and vibration. This Article was pretty informative. It wasn't an analogy to how earthquakes work, I was trying to make reference to some other internal force that wouldn't produce a net displacement. ... Even with the shifting mass, The thickness of the crust is staggeringly thin compared to the mantle and core. If you shrunk the earth down to the size of a grapefruit the crust would be only thick as a piece of paper. Or even thinner. Not to mention continental crust is much less dense than the material in that composes the rest of the earth. It's just hard to imagine how the slippage of a tiny piece of the crust could cause the axis of the earth to change. Cool.

[Xei]

You missed Xaq's (and my) point. Momentum doesn't need to be conserved if energy leaves the system. That's why the example of a running person is a poor one unless you take into account the internal forces.