NASA Details Earthquake Effects on the Earth

Cuyamaca writes " NASA scientists, using data from the Indonesian earthquake calculated it affected Earth's rotation, decreased the length of day, slightly changed the planet's shape, and shifted the North Pole by centimeters. The earthquake that created the huge tsunami also changed the Earth's rotation." You now have 2.68 fewer microseconds each day to do whatever it is you do.

Comments

So that's why my watch is running slow.

[IO ERROR]

The researchers concluded the Sumatra earthquake caused a length of day change too small to detect, but it can be calculated. It also caused an oblateness change barely detectable, and a pole shift large enough to be possibly identified. They hope to detect the length of day signal and pole shift when Earth rotation data from ground based and space-borne position sensors are reviewed.

Too small to detect? Then why is my watch running slow?

Seriously, this means we'll need an additional leap second once every thousand years or so. Unless, of course, something else changes the length of the day, which will likely happen first.

Makes you wonder...

[Anonymous Coward]

It seems to me that changes like this could have a dramatic impact on global climate. I've recently been accused of dropping flamebait before, and that's not my intent, but doesn't it seem that if the earth can just "adjust" like that, and kill hundreds of thousands of people (impacting millions) that it's possible that global warming might be just another natural adjustment? Or wait... did emissions cause the earthquake...? hmmm....

Pangea

[sameerdesai]

I read on CNN science page that scientists normally look for big events like these (quakes measuring more than 9) in order to learn more about earthquakes. However it was extremely difficult to learn anything as most of the fault lines are deeply buried in ocean bed. Other theory is that these kind of pheneomenon was what resulted in formation of all the continents as we see today from a big land mass lump called Pangea which existed millions of years ago. Another theory is now that these continents are on move again getting closer to forming a big lump. Australia is on a collision course with Asia and North America with Europe. Africa is pushing up on Europse and reducing the Mediterranean region. Considering the technological knowledge this is really neat however considering human lives this is very very sad incident.

So How Long Is A Day, Anyway?

[ferrellcat]

I always thought it was 24 hours. Is it now 24 hours - 2.68 microseconds, or has it ALWAYS been very close to, but not exactly 24 hours?

Lost time, gained life

[NeuroAcid]

Someone please help me out here. If we lost time in our day, that would mean the Earth is spinning faster. I thought that the faster an object moves, the slower time goes. So wouldn't this sort of cancel everything out in the long run?

Re:Earth-rearranging earthquakes commonplace

[Trolling4Columbine]

"It's suppose it's events like these that reveals how insignificant we are in the grand scheme of things."

And I know it's not a popular sentiment, but it aslo puts man's capability to affect the Earth into perspective. More energy was released by this quake than mankind is capable of producing, yet we are supposed to believe that we can significantly alter the Earth's climate in a mere 130 years?

Any long-term statistics?

[Spy der Mann]

Like how many of these earthquakes have happened? What's THEIR contribution to altering the Earth's rotation?

Assuming that these earthquakes are completely random, and have a more or less uniform distribution (well, actually around the limits of the tectonic plaques), I assume that in average the earth will have the same rotation speed. Some earthquakes will accelerate it, others will slow it down.

This earthquake just happened to be the first one whose effects could be MEASURED. First sample, doh?

Frankly this "oh wow look! the earthquake was so powerful it affected the rotation speed of the Earth!" stuff makes me laugh.

Questionable Article? Conservation of Energy?

[EXTomar]

First, I believe the Sun and Moon perturb the Earth's rotations at perigee and appogee in terms of miliseconds. Wouldn't the effect of these two bodies "wash" the any microsecond change in the rotation of Earth?

Second, what about the conservation of energy? If the angular moment of Earth changed (according to the article earth speed up) where did the energy come from? For the Earth to speed up, energy has to be added to the angular moment of Earth. Even if a chunk of the Earth's mass shifted somewhere the energy is still conserved because it came from somewhere else.

Everything on Earth is still on Earth although with a quake this big they aren't in the same places. Where did the extra energy come from to speed up the planet? Moving things around on Earth does not change the angular momentum of the planet.

Re:I wonder...

[ZB Mowrey]

Unlikely. Earth's mass remains the same, so the orbit around the sun is unaltered.

False. The gravitational pull of the earth attracts additional matter from space on a constant basis, so its mass is *always* increasing, even if the increase is barely measurable and totally imperceptible.