Heating of the earth's core

  • Thread starter carl fischbach
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  • #61
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Well, if this pet hypothesis has some merit, it would have some potential for a paradigm shift and not only for Venus, since the same mechanisms are working on Earth. So we're back on track ..eh thread.
 
  • #62
P.S. your #2 gives a "partial melting of the planet's surface" but studies show that the entire surface was done over as they can find NO impact craters older then about 1/2 million years old.

You need enough heating to melt the entire face of the planet, and probably 'plus some' then too!
 
  • #63
Originally posted by Andre
Well, if this pet hypothesis has some merit, it would have some potential for a paradigm shift and not only for Venus, since the same mechanisms are working on Earth. So we're back on track ..eh thread.
Only sorta, as you answer explains a/the makeover, (of Venus) not the mechanisms of regular, and consistent, heating, as the age of the planet implies the requirement that there be a heating source .
 
  • #64
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Right. In the narrative I was cautious:
causing the planet to melt partially or as a whole
just to leave options open. I should have repeated that in the conclusions.

The turning energy of Earth is enough to heat it several 10,000 degrees.
 
  • #65
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not the mechanisms of regular, and consistent, heating, as the age of the planet implies the requirement that there be a heating source.

The heat source is drag within the fluid outer core. The mechanism on Venus is dead as there is no more rotation. On Earth it has just began very hesistantly and intermittently.
 
  • #66
Originally posted by Andre
The heat source is drag within the fluid outer core. The mechanism on Venus is dead as there is no more rotation. On Earth it has just began very hesistantly and intermittently.
Uhmm, got a reference for that one, cause of what I have read the solid inner core is turning slightly differentially to the outer liquid core, measurable in a human lifetime.

As for it being the 'drag' as you state, needs better proving......(?)
 
  • #67
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As for it being the 'drag' as you state, needs better proving......(?)

Absolutely. It's another pet hypothesis but let's say highly controversial. Let's suppose that the mechanism of wandering solid inner cores due to differential precession has happened already on Earth for brief period(s) what would we expect to find?

For one, a much hotter inner Earth than could be expected of natural causes. And we may be looking at that.

But there may be many more effects that we are looking at too, but don't understand.
 
  • #68
In some of what I had read, recently, there was a mention of the cores rotation, "precession" I'm not certain that it was pegged as that or that there was metion of that and it's calculated effects, (but I will, {God willing} if I have the chance, go re-read it for that) but the reality is that there is an ongoing 'differential rotation' of the solid inner core, and it (the solid inner core) is thought to be plating itself, there is evidence of such, (althought I haven't seen it, I'd still give it the benefit of the doubt because of the source) hence the current status would probably be seen as "cooling off". Any 'precessional force' acting upon it, would (probably) simply be "back-timing its thermal history".
 
  • #70
Interesting but I went and did the re-read and the talk of a 1% precessional rate that allows the solid inner core to rotate once extra, within the planet, every ~400 years.

So where is the tremendous force that is needed to cause that to brake hard enough as to cause to arise enough friction induced heat as to melt of the surface of a planet?

(cause it takes LOTS of heat to do that)
 
  • #71
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It is building very gradually just a bit in analogy like this:

http://www.astronomynotes.com/gravappl/s10.htm

The differential gravity pull of Earth and Moon as in the third figure shows an example of exchange of momentum. Similar to the process of the moon, the assymetric gravity on the previous equatorial bulge of Venus pulls the planet ahead of its orbit, resulting in a slow spiral outwards. As the radius of the orbit increases the angular momentum of its spin transfers to the orbit of the planet.

Parameters are quite different of course and the process with Venus was likely more complicated. A tidal bulge is much smaller than a planets equatorial bulge.

I propose the next process:
In case of precession, the angular momentum vector is changing direction. Looking at the vector compounds in two dimensions, transfer of momentum takes place in both dimension and back when a precession cycle is completed. The sun in the Earth precession cycle gravity interactions "takes"a proportional part of the momentum in the first stage of the precession cycle in one dimension and "gives it back" in the final stage, transferring it between the two dimensions. However it is possible that a part of the momentum vector, that of the core, is getting misaligned. Then this process of transferring momentum between the dimensions is only taking place on the mantle part of the angular momentum. With diverging vectors the numerical vector is always less than that of the components. When the core and mantle realign in a chaotic process, dissipating a lot of energy, then the momentum at that moment is fixed at a lesser value and when the gravity interaction "gives" momentum back, it is still proportional, to the lesser value. So not all spinning momentum is retransferred. An this went on for millions perhaps billions of years repeating the process about every 100,000 years.
 
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  • #72
Well, as I had said, the article I had read told of the precession acting in a manner as to Cool the Earth, the (suspected) 'plating' being evidence of a cooling process occuring at present.

Slowing that down would simply slow down the Cooling, but does not generate enough heat to melt out the surface, not to the best of my knowledge.

As for your invocation of a need of 'dimensionality', matter is in 3 D, acts in 3 D, unless you can demonstrate your 'dimensional crossing' as a realistic method of what, "energy transfer" you said?

Sound like you have it all worked out in your head, if it is the right answer, others will recognize it/that, otherwise you'll probably find lots of people telling you you need to learn 'this' 'that' 'something else'.....
 
  • #73
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FYI

I had seen this article published May 8th somewhere else,


http://www.nature.com/nsu/030505/030505-5.html
Potassium heated Earth's core
"The iron-rich core contains lots of radioactive potassium, which generates heat as it decays, say V. Rama Murthy, of the University of Minnesota in Minneapolis, and colleagues. This supplements the heat still in the Earth's bowels from its fiery formation 4.5 billion years ago."

Now I see a new article, 10 December 2003:
http://www.berkeley.edu/news/media/releases/2003/12/10_heat.shtml
Radioactive potassium may be major heat source in Earth's core
excerpt
"Balancing the heat generated in the core with the known concentrations of radiogenic isotopes has been difficult, however, and the missing potassium has been a big part of the problem. One researcher proposed earlier this year that sulfur could help potassium associate with iron and provide a means by which potassium could reach the core.

The experiment by Lee and Jeanloz shows that sulfur is not necessary. Lee combined pure iron and pure potassium in a diamond anvil cell and squeezed the small sample to 26 gigapascals of pressure while heating the sample with a laser above 2,500 Kelvin (4,000 degrees Fahrenheit), which is above the melting points of both potassium and iron. She conducted this experiment six times in the high-intensity X-ray beams of two different accelerators - Lawrence Berkeley National Laboratory's Advanced Light Source and the Stanford Synchrotron Radiation Laboratory - to obtain X-ray diffraction images of the samples' internal structure. The images confirmed that potassium and iron had mixed evenly to form an alloy, much as iron and carbon mix to form steel alloy.

In the theoretical magma ocean of a proto-Earth, the pressure at a depth of 400-1,000 kilometers (270-670 miles) would be between 15 and 35 gigapascals and the temperature would be 2,200-3,000 Kelvin, Jeanloz said.

"At these temperatures and pressures, the underlying physics changes and the electron density shifts, making potassium look more like iron," Jeanloz said. "At high pressure, the periodic table looks totally different."

"The work by Lee and Jeanloz provides the first proof that potassium is indeed miscible in iron at high pressures and, perhaps as significantly, it further vindicates the computational physics that underlies the original prediction," Bukowinski said. "If it can be further demonstrated that potassium would enter iron in significant amounts in the presence of silicate minerals, conditions representative of likely core formation processes, then potassium could provide the extra heat needed to explain why the Earth's inner core hasn't frozen to as large a size as the thermal history of the core suggests it should."

Jeanloz is excited by the fact that theoretical calculations are now not only explaining experimental findings at high pressure, but also predicting structures.

"We need theorists to identify interesting problems, not only check our results after the experiment," he said. "That's happening now. In the past half a dozen years, theorists have been making predictions that experimentalists are willing to spend a few years to demonstrate." "
 
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  • #74
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I have read that the usual "leap second" correction that has been added almost yearly for the last 20 years to make up for the difference in the earth's rotation versus the atomic clock standard has not been required in the last five years.

Would this imply that the earth's rotation has increased? Could this be due to a contraction of the earth's core? If so would this cause tension along tectonic plates and an increase in earthquake activity?

I would be pleased to read the groups thoughts about the questions posed here.
 
  • #75
Originally posted by DAvidM
I have read that the usual "leap second" correction that has been added almost yearly for the last 20 years to make up for the difference in the earth's rotation versus the atomic clock standard has not been required in the last five years.
Would this imply that the earth's rotation has increased? Could this be due to a contraction of the earth's core? If so would this cause tension along tectonic plates and an increase in earthquake activity?
I would be pleased to read the groups thoughts about the questions posed here.
Perhaps you should start a new thread on it??
 
  • #76
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The earth's solid core is supposed to be spinning a bit faster than the crust/mantle daily 2/3 second x 365 days in a year means the inner core is gaining on the outer part of the planet about 4 minutes!
http://www.columbia.edu/cu/1996/0830/d.html [Broken]
"The inner core rotates in the same direction as the Earth and slightly faster, completing its once-a-day rotation about two-thirds of a second faster than the entire Earth. Over the past 100 years that extra speed has gained the core a quarter-turn on the planet as a whole, the scientists found. Such motion is remarkably fast for geological movements -- some 100,000 times faster than the drift of continents, they noted. The scientists made their finding by measuring changes in the speed of earthquake-generated seismic waves that pass through the inner core. "
 
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  • #77
Originally posted by NileQueen
The earth's solid core is supposed to be spinning a bit faster than the crust/mantle daily 2/3 second x 365 days in a year means the inner core is gaining on the outer part of the planet about 4 minutes!
http://www.columbia.edu/cu/1996/0830/d.html [Broken]
"The inner core rotates in the same direction as the Earth and slightly faster, completing its once-a-day rotation about two-thirds of a second faster than the entire Earth. Over the past 100 years that extra speed has gained the core a quarter-turn on the planet as a whole, the scientists found. Such motion is remarkably fast for geological movements -- some 100,000 times faster than the drift of continents, they noted. The scientists made their finding by measuring changes in the speed of earthquake-generated seismic waves that pass through the inner core. "
Thanks for the backup of what was said, on the previous page (7)
 
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  • #79
Originally posted by Nereid
This question (or something very similar) was also raised in the Astronomy board:
https://www.physicsforums.com/showthread.php?s=&threadid=11993
Followed the links nice articles, but not really about the "heating of the Earth's core", now is it, it is about time, and there is another thread somewheres on the same subject...time...
 
  • #80
Nereid
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Mr Parsons wrote: but not really about the "heating of the Earth's core", now is it, it is about time, and there is another thread somewheres on the same subject...time...
However, the topic of the 'leap seconds', and their possible relationship to the Earth's rotation rate, plate tectonics, etc was the subject of several posts just a little earlier ...
 
  • #81
Yup, one rotation more, about every 400 years, no doubt there are friction forces there, but the addition to the heating, from that, well, we would need "do the Math" to know better just how accountable that factor is...

As for the rest....?

(Hint..."Fuse Ball")
 
  • #82
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Livermore scientists unveil melting point of iron

http://www.eurekalert.org/pub_releases/2004-01/dlnl-lsu012104.php

LIVERMORE, Calif. -- Two scientists at Lawrence Livermore National Laboratory have discovered that iron in Earth-core conditions melts at a pressure of 225 GPa (or 32 million pounds per square inch) or about 5,100 kelvins (8,720 degrees Fahrenheit).
Determining the melting point of iron is essential to determine the temperatures at core boundaries and the crystal structure of the Earth's solid inner core. To date, the properties of iron at high pressure have been investigated experimentally through laser-heated diamond anvil cells, shock compression techniques and theoretical calculations....
 
  • #83
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Very late into this topic. But I have another theory concerning the presence issue of heat at the Earth's core.

The Moon.

That is because the Moon's tidal influence on the Earth does not end at the ocean floors. For just as the Moon orbits around the Earth, the Earth in its turn is effectively wobbled on its axis by the moon.

I do not have the exact figures regarding the Earth's rotational displacement, but like water that rolls around the inside of a glass when you give it a little circular momentum, so too the Moon causes the Earth's liquid interior to wobble and occilate in line with the Moon's passing.

I have never seen a model for this interaction, but I would be pretty sure that such an effect generates side-real friction tides inside the Earth's core, which in turn generate heat between the zones.

As for comparison to Venus and Mars, well we should include Mercury in this scenario, because then we can note that only the Earth has such a sizable moon in orbit around it.

So, maybe just maybe the Moon is the hidden factor in all of this.

Aqua
 
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  • #84
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I also add this link to some interesting stuff about the Moon.

http://www.enviroliteracy.org/subcategory.php/242.html [Broken]

Aqua :smile:
 
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