Powerful Chile Quake 'Shifted Earth's Axis'

[Skul]

The powerful earthquake that killed hundreds of people in Chile on Saturday probably shifted the Earth's axis and made days slightly shorter, a Nasa scientist has said.

Richard Gross, a research scientist at Nasa's Jet Propulsion Laboratory in California, calculated how much the axis may have changed in position following the the disaster.

More than 700 people died and two million are estimated to have been affected by the 8.8-magnitude tremor and subsequent tsunamis.

The quake, the most powerful to hit the nation in 50 years, sent shockwaves out from the epicentre 70 miles from Chile's second city, Concepcion.

Buildings and roads collapsed and 500,000 homes have been left severely damaged.

Six aid workers died when a plane carrying them to Concepcion crashed.

The team was on its way to help organise accommodation for those left homeless by the disaster.

Soldiers were sent to patrol Concepcion's streets after mobs set fire to shops and started looting them, hindering attempts to rescue survivors.

If the planet's axis did shift by 8cm during the quake, days would have shortened by 1.26 microseconds, Mr Gross calculated.

A microsecond is one-millionth of a second.

Earth days are 24 hours long because that is the amount of time it takes the planet to make one full rotation on its axis, so shifting the axis would affect rotation.

The quake shifted the Earth's axis by even more than the 9.1-magnitude tremor off Indonesia that started the deadly tsunami in Asia in 2004, according to Mr Gross.

This was partly because the fault line responsible for the quake in Chile "dips into Earth at a slightly steeper angle than does the fault responsible for the 2004 Sumatran earthquake", he said.

The different angle made Saturday's tremor more effective at moving Earth's mass vertically and shifting the planet's axis, Mr Gross continued.

The 2004 quake in Asia, which killed hundreds of thousands of people, caused the Earth to move by around 7cm.

It chopped an estimated 6.8 microseconds off the length of a day, Nasa said.

Source: Yahoo!
http://uk.news.yahoo.com/5/20100303/twl ... d0ae9.html

Shorter by 1.26 microseconds, eh? Yeah, I did notice it getting darker a little earlier than usual the past few days...

[Earl]

Ah, yes, those microseconds seem to last so long.

[i_like_1981]

Ah, yes, those microseconds seem to last so long.

To me it's not the amount of time it changed the length of the day by, more the fact that the earthquake was powerful enough to affect the Earth's axis to the extent where it had an effect of the day length. The shocking thing is it actually made the day a bit shorter! 8.8 on the Richter Scale is bloody powerful. I can't imagine how it would feel to put up with that for even a couple of seconds...

Best regards,
i_like_1981

[Fat Man]

Ah, yes, those microseconds seem to last so long.

To me it's not the amount of time it changed the length of the day by, more the fact that the earthquake was powerful enough to affect the Earth's axis to the extent where it had an effect of the day length. The shocking thing is it actually made the day a bit shorter! 8.8 on the Richter Scale is bloody powerful. I can't imagine how it would feel to put up with that for even a couple of seconds...

Best regards,
i_like_1981

It's normal for the rotational period of the Earth to go through these small fluctuations.

The Earth's axis actually wobbles like a toy top. A cheap toy top!

Along with the usual precession that take about 26,000 years, the Earth's axes also make little wobbles that take about 11 years on average.

The next thing you know, some of these whacked out anti-obesity crusaders are going to start blaming us fat people for all these earthquakes.

We're already getting blamed for global warming!

[Agent 47]

NEWSFLASH - DON'T BELIEVE EVERYTHING YOU READ ON THE INTERNET...

Earth days are 24 hours long because that is the amount of time it takes the planet to make one full rotation on its axis, so shifting the axis would affect rotation.

What?

WHAT?

That last bit doesn't quite make sense.

Surely shifting the axis of rotation wouldn't necessarily affect the length of a day, but changing the SPEED OF ROTATION would. Wouldn't it?

Here's something that I looked up on the internet for clarification -

http://www.abc.net.au/news/stories/2010 ... ion=justin

Quake shortened Earth's days
By Simon Lauder
Posted Wed Mar 3, 2010 10:41am AEDT

...

He, (Dr David Kerridge from the British Geological Survey), says the quake was strong enough to alter the distribution of the earth's mass and therefore speed up the rotation of the planet.

...

He says people can understand how the shift speeds up the earth's rotation if you imagine an ice skater spinning on an axis that runs from her head to her toes.

"When she puts her arms out, then she rotates quite slowly. When she brings her arms in, she begins to rotate much faster," he said.

"That's because she is decreasing her moment of inertia by bringing in her arms, by bringing the mass closer to the rotation axis. But angular momentum stays the same, which means rotation rate increases.

"Here it's the same kind of effect, but a very, very tiny one given the huge mass of the earth and the very small changes that have been made at the surface."

NASA geophysicist Richard Gross has told the Bloomberg newsagency the quake sped up the rotation of the earth enough to shorten the day by an estimated 1.26 millionths of a second.

Now that makes more sense - the mass of the Earth has been redistributed, AND SO WE'VE SPED UP, making the days shorter.

Ahhh, what would we do without the good old internet to look all this up on!

[i_like_1981]

A good bit of research done there, dickfilthy. So, the Eath's mass has been redistributed and that is the real cause of the slight shortening of the Earth's day. And I use the word "slight" in its very strongest content. It really is worth nothing at all, but I guess the fact it affected a universally-known measurement of time even in a minuscule way is enough to make mouths drop. By the way, what gave you the idea for your username? I'm quite interested to know.

Best regards,
i_like_1981

[Agent 47]

So, the Earth's mass has been redistributed and that is the real cause of the slight shortening of the Earth's day. And I use the word "slight" in its very strongest content. It really is worth nothing at all, but I guess the fact it affected a universally-known measurement of time even in a minuscule way is enough to make mouths drop.

Hell yeah. The forces involved in accelerating a planet, even a tiny little bit, would be huge. Accelerating a planet! Truly mindblowing.

Wouldn't it be great if we could capture some of that energy though.

I think that was one of the many things that Nikola Tesla was pursuing. It's been ages since I read anything about Tesla, but from memory, I think he saw the planet as a giant spinning electric motor/generator, and he wanted to tap into the associated electric field surrounding us, to get "free" energy. I think it was something like that.

By the way, what gave you the idea for your username? I'm quite interested to know.

Ahhh, well, there are several layers to that. It's a word puzzle. It's an enigma. It's a mystery wrapped in a riddle. And, oh yeah, there was some alcohol involved!