Geomagnetism and the rate of Sea-floor Spreading

Ah. So we're talking about, what, 80,000,000 square kilometers of sea floor being produced and 80,000,000 square kilometers of subduction? Assuming about 1,000 degrees centigrade magma (a fairly low estimate) being exposed to the water, and only the top 100 meters are transferring their heat to the water (preposterously low), and assuming a specific heat of 0.3 cal/gm, and density of 2.5 gm/cm^3, that's 6e21 calories. That's enough to boil 6e19 grams of water (6e16 liters; 6e13m^3). The atlantic's depth averages about 4,000 meters, giving a volume of 3.2e11 cubic meters of water. In short, the heat released by this would be enough to boil off the entire atlantic ocean 200 times over.And noah isn't pressure-broiled alive... how?Not to mention that the vast majority of the sea floor is sedimentary for a good ways down. ------------------
"Illuminant light,
illuminate me."

Well lets see. Specific heat c of water is ~4200 J kg^-1 K ^-1 and for basalt c = ~800 J kg^-1 K ^-1 If we were to take variables:T₁ = 1300 K
V_o = 1,400,000,000,000 m³
V_l = 7,000,000,000 m³Where T₁ is initial temperature of basalt and V_o is volume of oceans and V_l is volume of oceanic crust with a thickness of 100 m. From this we can deduce that this amount of heat (1000 K) if transfered directly to the superposing oceans without any heat loss by other means could heat 7 x 10⁶ km³ of ocean water by 190 K, or the entire ocean by 1 K.If we cool the entire crust of 6 km we could heat 7 x 10⁶ km³ of ocean water by 38000 K, or the entire ocean by 60 K. If we go further to account for the whole lithosphere the equations will get more complicated because of the geothermal gradient.If this is right, and considering the proposed mechanism of lithospheric cooling (hydrothermal circulation) the problem isn't that extreme. I may not have done my math right, its been a while since I had done similar calculations.[This message has been edited by TrueCreation, 09-25-2003]

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So we're talking about, what, 80,000,000 square kilometers of sea floor being produced and 80,000,000 square kilometers of subduction?

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I once calculated that cooling of the entire sea floor (added in edit: crust and lithosphere) and then solidifying it would release about 10^28 J of heat, which is coincidently the amount Baumgardner claims is released as gravitational potential energy from subduction. I seem to recall that Baumgardner claims that the heat from the subduction process might somehow be carried away by superheated jets but it seems to me that won't work for the entire sea floor. It has to stay molten to spread and then must boil the oceans. 10^28 J is about 3 x more heat than required to boil all the water in all the oceans and it only takes the boiling of a small fraction of the heat problem, along with other problems with CPT in some detail a while back.http://EvC Forum: Creationist Baumgardner: one of the top mainstream mantle/plate tectonics simulators! -->EvC Forum: Creationist Baumgardner: one of the top mainstream mantle/plate tectonics simulators!Here is cute little quote from JB's web page
COMPUTER MODELING OF THE LARGE-SCALE TECTONICS ASSOCIATED WITH THE GENESIS FLOOD | The Institute for Creation Research

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to yield a Rayleigh number low enough to be consistent with the available spatial resolution. For the calculation described below, a reference viscosity mo of 1 x 10^13 Pa-s, a thermal conductivity of 2 x 10^10 W m-1K-1, and a radiogenic heat production rate of 0.02 W/m3 are used.

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The mantle viscosity is of course many orders of magnitude too low and the the thermal conductivity is really out of site. How many orders of magnitude is this above the thermal conductivity of any real material? Baumgardner's CPT calculations are a classic case of garbage in garbage out.
JB et al say

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Cooling of new ocean lithosphere at the spreading centers would be expected to heat the ocean waters throughout the Flood.

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Of course it would not only heat them it would boil them away.JB has one of my all time favorite bit of creationist "logic" on his web page

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It plausibly leads to intense global rain as hot magma erupted in zones of plate divergence, in direct contact with ocean water, creates bubbles of high pressure steam that emerge from the ocean, rise rapidly through the atmosphere, radiate their heat to space, and precipitate their water as rain. That no air-breathing life could survive such a catastrophe and that most marine life also perished is readily believable.

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Anyone should easily see how implausible this most of this really is however it is not only plausible but inevitable that NO air breathing life, included Noah and company could have survived. I discussed the consequences of boiling even a small fraction of the oceans on another thread.There is no way around the fact that CPT would have cooked the earth to death. Instead of CPT is should be call SAS for Steamed Ark Soup.It is sad that an obviously intellegent young person such as TC is wasting so much effort trying to use an obviously failed model to try to validate a long falsified myth. Why not try to do some calculations showing that Santa Claus could really deliver all those toys in one night? Maybe if you reduce the viscosity of air by 8 orders of magnitude and use a sled flying velocity of 10^10 meters per second you can do calculations showing that it could work. It seems to me they will be about as realistic as Baumgardner's CPT calculations.Randy
PS I wonder what ever became of Tranquility Base. We used to have TC and TB defending the global flood but lately it just seems to be TB.[This message has been edited by Randy, 09-25-2003]

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If we cool the entire crust of 6 km we could heat 7 x 106 km3 of ocean water by 38000 K, or the entire ocean by 60 K. If we go further to account for the whole lithosphere the equations will get more complicated because of the geothermal gradient.

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You left out heat of fusion for the crust but that's not a huge effect and you probably should use 1000 J/kg-K but that is also not too big. However, you have to account for the lithosphere. This is a much bigger effect. Where does the heat go? How does it get out without boiling the oceans. How did enough heat get out to cool the supposedly young lithosphere to the point that it seems millions of years old even with boiling the oceans? I don't think you can do like JB and use a thermal conductivity many orders of magnitude above any real material to solve this problem and even if you do you will certainly boil the oceans away.Here are some numbers that may help you but I don't think you can solve the problem.http://gore.ocean.washington.edu/...cean410/notes/unit15.htmRandy

We both made mistakes. First, yours:1) The atlantic is a lot bigger than 1.4 trillion cubic meters of water and 7 billion cubic meters at 100m thick. I looked up the precise size, and it's even larger than I listed (although area actually cancels out in the equation). It's 1.057e8 km^2, not my 8e7 estimate. That's 1.057e14 m^2. Given an average water depth of 4000 meters and heat transfer zone depth of 100 meters, V0=4.228e17m^2, and V1=1.057e16m^2 You're waaaaay off.2) "heat loss by other means"? What sort of possible explanation could you have? Losing heat *into the earth*?It's easiest to calculate in calories like I did, BTW, since 1 cal heats 1 gram of water 1 degree at STP. Of course, that's for pure water, but it's not too different for salt water.Try again, using the right numbers this time! Now, mine: I used the wrong number of cubic meters in the water. Let's place the formula out here.T=temperature, dT=difference in temperature from the ocean.
A=area of the atlantic
Da=average depth of the atlantic
Dm=depth of magma that we're considering
Va=volume of the atlantic
Vm=volume of magma
Sm=specific heat of magma
Sw=specific heat of water
Dm=density of magma
Dw=density of water
Em = heat energy of magma
Ew = heat energy of water
dTw = change in temperature in waterdT=1000K
A=1.057e8km^2
Da=4000m
Dm=100m
Va=A km^2 * (1000m/km)^2 * Da=4.228e17m^3
Vm=A km^2 * (1000m/km)^2 * Dm=1.057e16m^3
Sm=0.3 cal/g
Sw=1.0 cal/g
Dm=2.5 g/cm^3
Dw=1.0 g/cm^3
Em=dT K * Vm m^3 * (Sm cal/g * Dm g/cm^3 * (100 cm/m)^3) = 7.9275e24 cal
Ew=Em cal = 7.9275e21
dTw=Ew cal * (1 K*g/cal) / (Dw g/cm^3 * (100cm/m)^3 * Va m^3) = 18.75 KOf course, this uses the preposterous estimate that only 100 meters of magma transfer their heat energy to the water over the course of an entire *year*. Now, while the current number would still be spewing huge amounts of steam into the atmosphere (and trapped gasses making the entire ocean horribly acidic and toxic, etc) (i'd also doubt a laden boat could sail in water bubbling like that, unless you expect somehow that all steam bubbles will collapse before they get to the surface), let's look at how quickly magma *actually* dissipates heat into water. Even pretending that the Atlantic heat can just go into the other oceans (do you know how fast conveyors go? What, do you expect conveyors moving hundreds of miles per hour, but Noah riding just fine?), there's still another problem. Heat transfers *much* more quickly than the values that I used that under water, especially due to pillowing (which would be happening on a *massive* scale here). How quickly? Well, the mid-atlantic ridge with the magma in a thin line transfers about 2.3e19 cal/yr. It manages such a heat transfer with *very* minimal exposure due to two things: a) cracks in the cooled rock due to pillowing extend for hundreds of meters deep in places, and b) the lower reaches are rapidly cycles through by magma. With this, you're going to be looking at what could only reasonably be *kilometers long* cracks from pillowing (have you ever seen an underwater volcano before, out of curiousity? the rate that they transfer their heat is tremendous). The effect would be, really, staggering. Even if you scale the 100 meters of magma's worth of heat up to only 1 km, all of the oceans would be boiling.Just the immediate quench of exposed magma is almost unthinkable, the wave of steam it would release... talk about causing a megatsunami. Every freshly exposed area of magma will release a huge bubble of steam shooting to the surface. And if the mantle isn't nice and smooth, but is erupting due to trapped gasses, the situation becomes far, far worse.I really don't think you've thought about the heat situation very much.------------------
"Illuminant light,
illuminate me."

I decided to redo this from scratch since I know I got different numbers from T.C. when I did it before and like Rei calculated that the oceans would boil. I am doing the calculation for the entire ocean crust. Of course there is going to be some interesting weather while the oceans boil, probably steam driven hurricanes all over the earth and some unimaginable ocean currents. This will happen early from the 10^28 J that is released from gravitational potential energy of the subducting slabs as the authors admit. But even if this heat magically escapes and doesn't boil the oceans the heat from the new sea floor solidifying must. Here is my calculation. If anyone finds an error please let me know.The ocean crust is about 7 km thick. This is 7 x 10^5 cm.The surface area of the ocean is 361,000,000 sq km.There are 10^10 sq cm in a square km so the area is 3.6 x 10^18 cm^2.This makes the volume of the ocean crust 2.6 x 10^24 cc.The density is about 3.3 so we about 8.3 x 10^24 g of crust.The heat capacity is about 1 J per gram per degree KTo cool by 1000 K 8.3 x 10 27 would release 8.3 x 10^27 gThe heat of fusion is about 400 J per gram.To solidify would release 3.3 x 10^27 JThe total heat is 1.17 x 10^28 JThe volume of the world’s oceans is 1.4 x 10^9 cubic km.There are 10^15 cc in a cubic km.The volume of the oceans is 1.4 x 10^24 cc.The heat capacity of water is 4.2 J/cc-k.It take about 6 x 10 x 10^26 J to heat the oceans by 100 C leaving 1.1 x 10^28 J to boil the water.The heat of vaporization is about 2260 j/g at STP. We have 1.4 x 10^ 24 g of water so we need 3.13 x 10^27 J to boil the oceans at STP. As the atmosphere pressure goes up due to water vapor in the atmosphere the boiling temperature goes up but the heat of fusion decreases until it reaches 0 at the critical point. Note that just the heat of fusion alone is enough to boil the oceans so the calculation is not sensitive to the initial temperature of molten crust. The total heat looks like enough to convert the lower atmosphere to critical point steam. Steamed ark soup anyone?RandyAdded in edit: I calculate the the earth recieves about 4 x10^24 J of energy from the sun in a year. 10^28 J is about 2300 times as much. Why isn't the earth still hot? What I find really amusing is that after all this heat is released and the air is filled with water vapor, a very effective greenhous gas, the authors of CPT say that the next thing that happens is a massive ice age. Such passes for logic in the world of YEC.
[This message has been edited by Randy, 09-27-2003][This message has been edited by Randy, 09-27-2003]

TrueCreation wrote:"I have done my analysis and a
preliminary copy of an article I
will be illustrating it in can be
found here:http://www.promisoft.100megsdns.com/...is%20Grose/geomag.htm"An interesting article.The internal stratigraphy of deep sea sediments was being discussed in "Questions about marine sediments" at http://EvC Forum: Questions about marine sediments -->EvC Forum: Questions about marine sediments . One of the things that I found were some really nice color figures that shows how plate tectonics influences the types of sediments accumulating within the Pacific and Atlantic Ocean on pages 32 and 33 of "Marine Sediments". This article can be can be downloaded from:http://www.ldeo.columbia.edu/~rroberts/Lect-3.pdfIn addition, another study guide illustrated how plate tectonics influenced the types of sediments accumulating within oceans in "13. Overview: Marine Sedimentation" at:http://bell.mma.edu/.../UWMarineGeology/McDuffSediments.htmlThis web page contains some interesting figures, which show how plate tectonics influences the accumulation of different sediments. The figure that illustrates this process can found at:http://bell.mma.edu/~jbouch/UWMarineGeology/fs30-4.gifThis is figure 13-5 from:W.S. Broecker and T.-H. Peng (1982) Tracers
in the Sea, Eldigo Press, 690 pp.In the pdf file and the figure cited above, is showed there is a predictable stratigraphy of deep sea sediments that can found across both the Atlantic and Pacific Oceans. The curious thing is this stratigraphy is consistent with the sediments covering the oceanic crust as having accumulated during the slow movement of continental plates. However, it seems that it would be virtually impossible for the same stratigraphy of deep sea sediments illustrated in the figures shown in the pdf file and web page to have been created during a period of accelerated plate tectonics when the dynamics of the modern oceans were completely different than today.Just Some ThoughtsBill Birkeland

Since we are discussion this again I thought I would bump this thread. It looks like there is a sediment problem with runaway subduction as well as a heat problem.Randy

Roxrkool - Found your lecture to TC on "Mainstream Scientists" amusing. Engineers who make a living respecting laws of physics and thermodynamics would have never accepted current plate tectonic theory to begin with. It is fatally flawed without mechanisms. Doesn't the fact that no one can build a model of "convection currents" in the mantle without ignoring viscosity make the "mainstream scientists" in the earth science fraternity a little nervous that they may be suffering from groupthink?
I am an EE and understand a little about electromagnetic fields. I can tell you with confidence that the Magnetic poles have never "reversed" and especially with a nonperiodic frequency. No experienced Instrumentation Engineer would interpret fluctuating signal strength above and below an average to be a "Reversal". In the classic sense, your elite geology fraternity has interpreted a DC waveform with ripple as an AC waveform. There is no force in earth that will flip the huge gyroscopic inertia of the mass creating the flux lines of the field. PT is slowly crumbling with new data and lack of viable mechanisms.This message has been edited by Rod Nance, 01-07-2005 02:08 AM

How perfectly patronizing of you. First of all, I was reviewing TC's paper in that post, not "lecturing" him on the merits of plate tectonic theory.Secondly, I don't presume to think the theory of plate tectonics is flawless. I am fully aware of the convection problems, as well as the difficulties in modeling mantle plumes.Thirdly, no, I don't agree that it is fatally flawed. I think it's too soon to say such a thing. We still have a lot to learn about the chemistry and dynamics of the earth's interior. A few problems don't bother me at this point. Then how would interpret the alignment of magnetized minerals to the poles in recent and ancient rocks? Then I suppose it's good thing we don't have EEs running around collecting geologic paleomag samples, isn't it?? lolIncidentally, since I'm not expert in this field, isn't the strength of magnetic force a different thing entirely from the direction of magnetic force? Well then why don't you publish these astounding findings and topple the elite geologic fraternity? Or have you done so already?This message has been edited by roxrkool, 01-07-2005 02:56 AM

Most engineers, including me, have no problem with plate tectonics. What are the physical and thermodynamic grounds by which you reject plate tectonics? I can't tell what your objection is. Are you claiming there are no mantle currents, or merely that there are problems with the current models.Modelling convection currents within the mantle is as difficult as modelling the weather, and so the mantle current models struggle to reproduce observations, but current models definitely do *not* ignore viscosity. We can't directily measure the viscosity to plug into models, but it can be derived indirectly. This is from Earth Story, the Shaping of Our World by Lamb and Sington, p 105-106: In other words, you're wrong that current models ignore viscosity. Perhaps you were thinking of the problems of modelling plate tectonics in terms of mantle currents, also discussed in Earth Story: Congratulations on your double-E status, but since electromagnetic fields result from the earth's internal dynamo which is in turn a function of mantle currents which are inconstant, varying electromagnetic field strength and direction over time would appear inevitable, and the current state of the strength and direction is captured in rocks when they first cool, as happens at mid-oceanic ridges. The fluctuating field strength was measured by sensitive magnetometers pulled behind boats. After analyzing rocks from cores from the sea floor, the fluctuations were found to be due to opposite magnetizations. Higher field strengths were measured in regions where the rocks were magnetized in the same direction as the earth's magnetic field, while lower field strengths were measured in regions where the rocks were magnetized in a direction opposite to the earth's magnetic field.In other words, the reversals are not an interpretation, they're a measurement of the actual magnetic direction in the rocks. The earth's magnetic field is only a net magnetic field. It is made up of the contributions of the many individual mantle currents. Some of the currents contribute a magnetic field in the same direction as the net field, and some contribute an opposite field. The net magnetic field is the one we detect with a compass.As various mantle currents ebb and flow, their contribution to the earth's net magnetic field changes. These fluctuations are random, and over time the net contribution of all mantle currents can change to create magnetic fields in both the positive and negative directions. It is these reversals that are captured in the rocky base of the sea floor and is known as sea-floor striping.In other words, geophysicists do not believe the magnetic field reversals are due to huge flips of inertial mass in the mantle.--Percy

Never the less, it moves. Not being able to model the underlying currents doesn't stop the plates in their tracks. They move!And at an interesting rate.

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In the classic sense, your elite geology fraternity has interpreted a DC waveform with ripple as an AC waveform.

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As an EE, you should know that a rippled DC waveform can be produced by combining a flat DC waveform and a seccond AC waveform.So there, Mr. Smartypants ,Moose

Nope.You have interpreted a trace left by an AC waveform with a ripple on a different DC waveform merely because the trace of the AC waveform is lower in magnitude than the actulaDC waveform. They are not comparable.The trace of the AC waveform (that is, the magnitude of the frozen-in magnetic field in the rocks) cannot be meaningfully compared to the magnitude of the DC signal (the Earth's magnetic field today). We could, of course, calcute from the trace what the magnitude of the Earth's magnetic field was in the past, and indeed we have done so. For example, How Are Geomagnetic Reversals Related to Field Intensity?. And we find that the Earth's magnetic field has indeed reversed, and was sometimes greater than the current strength and sometimes less.The fact that the magnetic field of the rocks (in which the historic reversals are frozen) is less than the magnetic field of the Earth is irrelevant. Your "DC signal" is in fact an irregular and slow (in terms of human lifetimes) AC signal.

Hey guys. I appreciate your responses. I apologize if my post came across as "Smartypants"... not my intention.Percy, your reply in message 101 states:
"...current models definitely do *not* ignore viscosity."
However, this is at odds with one of the leading University researchers attempting to model the mantle with dynamo theory. My recent inquiry to his model assumption on viscosity resulted in the following response:".....Look, Rod, you can't really expect to dive into a subject
without doing quite a bit of groundwork. For example,
the current wisdom is that (a) viscosity does not have a
significant effect on the geodynamo (b) it is not
heat alone that drives the motions. To appreciate why
people think this way, you need to do some reading, and
(if you disagree with their conclusions) propose
alternatives........"It was a private email so I will not divulge the source here. If you are interested in the source - email me. It is correct that other forces are significant in the physics of modeling the planet - especially gravitational, inertial, and centrifugal forces. Cleary, a dynamo model is appropriate for atmospheric applications like weather. But it is inappropriate for modeling the mantle - where viscosity is significant. Try getting convection currents in a pan of pudding... you will only get burned pudding. No sound engineering model would ignore or suppress viscosity.
Since the models do not work with realistic viscosity parameters, it seems the "current wisdom" among the geological fraternity, as described by the University researcher, is to ignore or minimize viscosity. That is not good science. The error is similar to that made with cold fusion claims by a couple of engineers a few years ago. It didn't work either.Others have responded with good questions about the interpretation of residual magnetism data and the "DC ripple" analogy. Since I reject the concept of convection currents due to viscosity, the best explanation I have seen for the fluctuating geomagnetic field strength is the Hydroplate theory which I stumbled on a year ago while searching some biology sources for my premed daughter.Concerning the assumptions in the Hydroplate theory...
We know the universe is not infinitely old. The universe has a starting point in time as required by the law of entropy. No matter what assumption we make about that starting point or "origin", it is - "Supernatural" by definition - beyond the scope of the scientific method. In my analysis, the Big Bang assumption is no more or no less scientific than The Hydroplate theory assumption. However, the Hydroplate theory presents working mechanisms to explain not only geological data but phenomena in other fields of science as well (astronomy).I would like to stay and debate these things with you guys but just passing through. Since I don't have the time, I would encourage you to study details of the Hydroplate theory for an alternative explanation of the geomagnetic data - with working mechanisms.I found the history of Wegener interesting. He was also an outsider to geology. His moving plates hypothesis was ignored and scorned by the geology folks for almost 50 years until the geomagnetic data was misinterpreted as horizontal seafloor spreading (another problem with respect to fundamental physics).See the Hydroplate theory - Happy hunting!This message has been edited by Rod Nance, 01-08-2005 01:11 AM