Pulsating Equator


by billiards
Tags: equator, pulsating
billiards
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#1
Apr10-07, 07:58 PM
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William Astley said:
Why don't you start a new thread, to discuss the Pulsating Equator Hypothesis hypothesis. I would be interested to discuss, but I need a better base from which to start the discussion. What is the hypothesized mechanism? What drives it? Is it periodic?
I found myself wondering about the pulsating equator recently. For those not in the know, Andre presented this excellent nutshell description in a previous thread.
Diagnoses of the Ice Ages: Pulsating Equator

Abstract

We demonstrate that if the size of the equatorial bulge would pulsate around an equilibrium in an irregular 100ka cycle and with some ten-hundred meters ROM amplitude, then it would explain most of the symptoms of the ice age. Periods of maximum equatorial bulge size represent interglacials with high sea levels due to relatively small oceanic basins. Periods with a minimum equatorial bulge have low sea levels due to equatorial enlargement of the Oceanic basins. Furthermore, during contraction of the equatorial bulge, the poles are pushed upwards to much higher elevations, both effects combined, increase orographic effects enough to trigger glacier growth at high latitudes, which accumulates in ice sheet build ups. In this scenario, the reverse process, with an expanding equator and sinking poles are leading to the interglacials, in which transient effects like Heinrich events, Dansgaard Oeschger interstadials, melt water pulses find an easy explanation.
Check out this cool animation.

I was thinking that it it boils down to a fluid mechanics problem. Can you find a realistic solution to the Navier-Stokes equations that would allow for a pulsating equator?

The only force that is important in shaping the Earth (at a large scale) is gravity. If this is true then the only way you could get the equator to bulge (to my knowledge) would be to make it spin faster, and for it to pulsate it would have to slow down and speed up! Quite how that could happen is beyond me, I considered meteorites for a second, but after some consideration concluded that they would not be suitable. Unless there's some kind of transient anisotropy to gravity that we can't see in human timescales, I don't see any way the pulsating equator could physically work.

Discuss.
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Bystander
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Apr11-07, 08:18 AM
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1) Lacks a driver; 2) fails to account for distortion of the gravitational field (and gradient) resulting from the distortion of the mass distribution; 3) fails to account for movement of water in response to that distortion.
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Apr11-07, 09:26 AM
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Quote Quote by Bystander View Post
1) Lacks a driver; 2) fails to account for distortion of the gravitational field (and gradient) resulting from the distortion of the mass distribution; 3) fails to account for movement of water in response to that distortion.
That's a dissapointing assessment considering this for instance:

pertaining:
http://home.wanadoo.nl/bijkerk/LR05-Epica-dome-c.gif

I sent this Email:

A depersonalized cc:

Hi again....,

And thanks again for reacting. I have read your mail now a bit more in detail. I fully understand the caveats but I hope that your curiousity to the fundamental problems of our insights in of the recent geologic past in terms of system response, won't detract too much from...

I enclosed now one of the versions of the comparison of the ocean floor proxies with the Antarctic ice core. Let's first look at the graphs only, presuming that we don't know what those are, but knowing that dating did not happen independently (the lower was "tuned" to the upper, it seems for the last 500,000 years); but what would be input, output and what about system inertia? My guts feeling says that those are so closely related, that if one was input and the other output, then the system inertia would be negliglible on this time scale. Would I dare to say that system time constant could not be more than 1000-2000 years at most? But I'm no expert. Also it looks pretty linear to me and no feedbacks so to see?

Now what is the story? The valleys signify the glacial periods, the spikes are the interglacials. The isotope ratio values (deuterium in this case - dD) in the ice sheets (EPICA dome C) are supposed to be a approximation (proxy) for temperatures due to the slight differences in condensation rates for the different isotopes, depending on temperature at the condensation point. That's simple although I promise that major complications are coming up.

The benthic stack is a compilation of heavy oxygen isotope ratios (d18O) in the calciforous shells of certain bottom dwelling micro organisms (foraminifera), the shell remains are accumulating over the ages and buried in the sediments and can also be read as proxy data, but of what?

The temperatures down there at more than 1000 meters (3000ft) are usually fairly stable and it's unlikely that such excursions could be caused by temperature changes. Furthermore, I believe that laboratory tests have revealed a not much sensitivity to temperature changes. Therefore it is assumed that the measured d18O mostly represents the local d18O of the water. So it was argued that the d18O of the oceans vary between ice ages and interglacials. Evaporation favors light isotopes, leaving the heavier behind. So, during the building of ice sheets, less light water returns to the oceans and enirches the heavier isotopes in the oceans. Apparantly the benthic d18O is a proxy for ice accumulation and the benthic stack appears to tell us about the waxing and waning ice sheets.

Brilliantly thought out, but there are a few problems. If you do the math you see that you'd need a terrible amount of ice to match the numbers, but that was no problem in the time that this idea was constructed. Siberia was so large and so unknown in the USSR time, you could stack endless masses of ice over there. But then the mammoths came and gone was the ice sheet of Siberia, zilch, no ice sheet whatsoever, a few glaciers at the most.

Second problem, the focus now, is: where is the inertia? Going up a spike; if the temps rise (system input), the ice starts to melt and takes a few thousand years to disapear, inertia number one, then the returning light waters to the oceans take x-thousand years to mix in fully all over the oceans to reach all the deep seas for the foraminifera to register it (system output). Inertia number two. Obviously the same problems exist for going down a spike and building ice sheets. So if the ice sheet - benthic d18O hypothesis is correct then you would expect a slow system repsonse of a series of two very slow basically first order systems of thousands of years. Not so, I would think that the mechanism would have especially problems with the steep shallow high frequency spikes. In a word, things don't seem to add up.

Since both graphs so closely related, it appears that there is no system in between at all. Hence it could be that both are output of an yet unknown third system. Would you agree with that?

And you can imagine the can of worms going open, when that hypothesis proves to be false, it's also one of the mainstays of global warming. Therefore it's paramount to be very sure that this type of system response is also rejected by the experts.

It will be fun to rebuild a new hypothesis on the old one. I have a pet idea or two.

Thanks again for listening

All the best

Andre

XLS sheet with data attached
Attached Thumbnails
LR05-Epica-dome-c.gif  

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Apr11-07, 11:40 AM
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Pulsating Equator


Foram 18O enrichment/depletion probably reflects seawater 18O enrichment/depletion; speculations on mechanisms for isotopic fractionation (sea level, SST, rainfall, etc.) infest the literature; there are no compelling arguments for any of the proposed mechanisms, and, therefore, no compelling arguments for selecting a particular mechanism to be further investigated for proximal cause.

That said, "polar-equatorial pulsation" won't affect local sea level; sea level conforms to the geoid; modify the shape of the geoid, and the shape of the oceans is modified, but the local sea levels are not.
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Apr11-07, 12:07 PM
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Quote Quote by Bystander View Post
Foram 18O enrichment/depletion probably reflects seawater 18O enrichment/depletion; speculations on mechanisms for isotopic fractionation (sea level, SST, rainfall, etc.) infest the literature; there are no compelling arguments for any of the proposed mechanisms, and, therefore, no compelling arguments for selecting a particular mechanism to be further investigated for proximal cause.
whatever the reason for the d18O variation is, you cannot dismiss the absence of inertia system response characterics. Why don't engineers ever respond in these threads? That should falsify the Rutherford hypothesis. whatever happened, it happened in the oceans not in the atmosphere.

That said, "polar-equatorial pulsation" won't affect local sea level; sea level conforms to the geoid; modify the shape of the geoid, and the shape of the oceans is modified, but the local sea levels are not.
We talk about very minor modifications on Earth scale ROM ~100 - 200 meters versus a radius of 6300km and it's exactly the persistence of the sealevel to maintain the geoid shape that causes the effects. Where the sea level shape remains constant, the pulsating earth does not.

Actually it was impossible Melt water pulse 1A in concurrence with the equally impossible clathrate event of the Amazone Fan 13-14 Ky ago that triggered the idea.
Andre
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Apr11-07, 02:51 PM
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Next I would like to draw the attention to this abstract

http://www.cosis.net/abstracts/EGU05...05-J-04737.pdf

and this outline of the maximum extend of the Late Weichselian Glaciation during the Last Glacial Maximum some 18-23,000 years ago, as well as this abstract about conditions in Lithuania.

Anybody happen to notice a little problem?
baywax
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Apr11-07, 05:48 PM
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Is this link about the lava lamp effect of our molten interior going to help explain the pulsating equator?

http://denali.gsfc.nasa.gov/sci_hi/s.../2003_4_c.html
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Apr12-07, 01:03 AM
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Quote Quote by baywax View Post
Is this link about the lava lamp effect of our molten interior going to help explain the pulsating equator?

http://denali.gsfc.nasa.gov/sci_hi/s.../2003_4_c.html
Who knows. I realize I was stealing the thread by showing the plethora of evidence supporting the little pet idea as a reaction on the ignorance fallacy challenge.

Anyway, the scientific method requires a physically feasible explanation. How feasible is it?

For one, it happens now: http://www.space.com/scienceastronom...ge_020801.html
albeit on a very modest scale, but a modest scale at a very long times >10,000 years may lead to something.

Explaining what could or could not be happening is quite something different. I believe I have speculated about the solid inner core not spinning inline with the mantle all the time, due to different torque/precession features, causing different turbulence patterns in the fluid outer core, which could alter the pressure equilibrium at the core mantle boundary.

Would that make sence?

edit: added

The variation in pressure on the mantle due to the variation in turbulence of the fluid inner core may result in a shape change of the CMB which is ultimately transfered to the Earth surface?
baywax
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Apr12-07, 01:20 PM
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Quote Quote by Andre View Post
Who knows. I realize I was stealing the thread by showing the plethora of evidence supporting the little pet idea as a reaction on the ignorance fallacy challenge.

Anyway, the scientific method requires a physically feasible explanation. How feasible is it?

For one, it happens now: http://www.space.com/scienceastronom...ge_020801.html
albeit on a very modest scale, but a modest scale at a very long times >10,000 years may lead to something.

Explaining what could or could not be happening is quite something different. I believe I have speculated about the solid inner core not spinning inline with the mantle all the time, due to different torque/precession features, causing different turbulence patterns in the fluid outer core, which could alter the pressure equilibrium at the core mantle boundary.

Would that make sence?

edit: added

The variation in pressure on the mantle due to the variation in turbulence of the fluid inner core may result in a shape change of the CMB which is ultimately transfered to the Earth surface?
Does the cool animation from Billards

http://home.wanadoo.nl/bijkerk/Pulsating-ice-age.pdf

also explain the mysterious rise in sea level you have noted in the past that cannot be explained by meltwater pulses?
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Apr12-07, 01:44 PM
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Perhaps, although a sudden sea level lowering, which killed the coral just as well as a sea level rise would be more logical to explain the methane hydrate release of the Amazone fan. Perhaps the transient was complicated.

It would also help explaining this one for instance:

http://geology.geoscienceworld.org/c...tract/30/4/379

Wuchang Wei, 2002, Beijing inundated by the sea within the past 80 k.y.: Nannofossil evidence; Geology; April 2002; v. 30; no. 4; p. 379-381

ABSTRACT

Examination of published data reveals that a marine bed in Beijing can be dated as 80 ka or younger on the basis of abundant nannofossils. This age is 30 times younger than that published previously on the basis of magnetostratigraphic and biostratigraphic interpretations. The abundant nannofossils and foraminifers suggest that Beijing was inundated by the sea within the past 80 k.y. The very recent nature of this marine transgression has profound societal and geological implications and thus calls for new studies and thorough evaluation of all relevant data sets.
Consider this that new study.

Also, trying to find more equatorial clathrate events. There seems one for the coast of India and the St Monica bassin of California is a good possibility. These are predictions BTW, required to see if the idea works.


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