Posted on 08/26/2005 11:21:48 AM PDT by anonymoussierra
WASHINGTON - The giant iron ball at the center of the Earth appears to be spinning a bit faster than the rest of the planet.
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The solid core that measures about 1,500 miles in diameter is spinning about one-quarter to one-half degree faster, per year, than the rest of the world, scientists from Columbia University's Lamont-Doherty Earth Observatory and the University of Illinois at Urbana-Champaign report in Friday's issue of the journal Science.
The spin of the Earth's core is an important part of the dynamo that created the planet's magnetic field, and researcher Xiaodong Song said he believes magnetic interaction is responsible for the different rates of spin.
The faster spin of the core was proposed in 1996 by two of the current study's authors, Paul Richards of Lamont-Doherty and Song, now an associate professor at Illinois.
The researchers studied the travel times of earthquake waves through the Earth, analyzing what are called couplets. Those are earthquakes that originate within a half-mile or so of one another but at different times.
They analyzed 30 quakes occurring in the South Atlantic and measured at 58 seismic stations in Alaska and found differences in the travel times and shape of the waves, indicating differences in the core as the waves passed through the center of the Earth.
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Analyzing those differences, they calculated that the core is spinning slightly faster than the rest of the planet and is a bit lumpy.
That solid inner core is surrounded by a fluid outer core about 4,200 miles across.
Since the planet is divided into 360 degrees of longitude, a core spinning one-quarter to one-half degree faster than the outer surface could take between 700 and 1,400 years to get one full revolution ahead.
But Song said in a telephone interview that he expected that rate to vary over time and sometimes the core might be spinning slower than the rest of the planet.
"What we see right now is a snapshot of a long time process between the magnetic field and the inner core," he said. "I do expect to see this rate change with time."
"What is surprising for us is that we could actually see it in such a short time scale," he said, noting the measurements had been made over less than a decade.
Geologists are used to thinking in terms of thousands or millions of years for geological processes, he said.
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The work was funded by the U.S. National Science Foundation and the Natural Science Foundation of China.
AN EASIER WAY IS WITH GPS...THEN YOU KNOW YOUR POSITION VERY ACCURATELY....UNLESS YOU HAVE BEEN DRINKING, OF COURSE.
thank you
This is the sort of English up with which I will not put.
-- Winston Churchill
:}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}thank you
We have no phrase for that. It's not an American thing to do.
Now you know whether your north or south of the equator.
We have a magnetic field spinning around an iron center at a relative rate of one cycle per 700-1400 years. Any physics folks want to do the math on what kind of current the Earth already produces?
I'm guessing that the rate of rotation makes tapping into it pretty much impractical in terms of the amount of power you'd get. It would be kind of like spreading 1/60 of a second's worth of Niagara Falls' output spread out over 700 years.
Ah I think you have that backwards... the outer side of any spinning object would of course cover a greater distance per revolution that any thing inside for the same revolution
I understand thank you"IamConservative"
Well, we could always set off some nukes and make it spin faster.
"We have no phrase for that. It's not an American thing to do."
You do not smile:{{{{{{{{{{{{{{{{{{{{{{thank you"RightWhale"
"A MAP IS NEEDED WITH MAGNETIC VARIATIONS SHOWN...TO ADJUST MAGNETIC NORTH COMPASS READINGS TO TRUE NORTH.
AN EASIER WAY IS WITH GPS...THEN YOU KNOW YOUR POSITION VERY ACCURATELY....UNLESS YOU HAVE BEEN DRINKING, OF COURSE."
Yep, knew the magnetic north true north thing. Just wondering if the core-crust differential had anything to do with it. The GPS thing was a joke as the receiver takes its cross and fix readings from satellites.
Hmmmmmmm GPS ... drinking ... A GPS enhanced pup-crawl!
Sounds good to me.
Cheers
Yeah, but then everybody's pants would fit funny.
Now what?
How would you say it in Polish. Perhaps someone here can translate directly.
I think the skater analogy has more to do with angle of momentum. However, I didn't do all that well at physics back in 62 so I'm not sure.
Now, with the molten layer between the core and the crust, could it be that the crust is slowly icreasing speed to match the core? Much as in a torque converter, the propeller (crust) takes some time to rev up to the speed of the impeller (Core). (Hope I've got my pro and im in the right order) ?????????
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