How To Tell The Nature Of The Mechanism Of The East Pacific Rise.

There are a number of models of driving mechanisms behind plate movements, just a few to mention:

- Mantle convection model;
- Slab suction;
- Gravitational sliding;
- Tidal friction of the moon;
- etc;

The proposed in previous posts mechanism "Magma Solidifying In The Crust Ruptures Caused By Moon/Sun Induced Crust Deformations" is completely different to them. Let's see how it fits East Pacific Rise spreading.

First, under "Crust Deformations" in this case we have the process the boundary plates are getting closer/more distant with moon month cycle. Let's leave Sun and planets effects for next postings. Moon orbit is inclined toward Equator plane. Thus, Earth twice a month is more stretched on Equator, twice a month is less stretched. Because of that the distance between plates varies with the period.

Now, let us ask some questions:

- Does the mechanism pump magma up?

Yes, vertical temperature/viscosity gradient in the gap between plates acts as a pump, less viscous magma is easier to get "sucked/pushed up" when the gap between plates increases. And after cooling the "more solidified" magma under the press of boundaries would try to find "easy" way, that is, partially to up-well. If the were no vertical viscosity gradient of magma between plates, the up-welling would not be significant. The magma up-welling depends on many factors, one of them is speed of boundaries spreading. The less speed, the higher the magma could be pumped up, Mid Atlantic Ridge can be an example, in my opinion.

-What signs specific to this concept would be left on/within crust, that can be measured experimentally?

1. I think, some semi-solidified regions could be left within the spreading crust, as the squeezed up magma would not flow uniformly. With proper instrumentals the anomalies could be found relatively easy, as their depth, I'd expect, would be less than 100 km.

2. The pumping up magma should produce specific earthquake pattern in correlation with month cycle.

3. Probably it would not be a bad idea to place precision sensors on both sides of the Rise to track their relative position. If monthly relation of the distance variation is found, that can be an evidence as well of the mechanism working on the ridge.

4. Probably, there should be some properties to be detected that depend on the crust tension.

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The difference between proposed concept and models mentioned in the beginning of this post is that the models operate with force that presumably acts on a plate, while the proposed concept deals with displacement, not with force. And variable displacement between plates have to exist according to lows of Physics, the question is - is it enough by amplitude to produce the detected effect of ridge spreading. Also it should be mentioned that the the speed of the spreading is greater closer to Equator regions, that correlates with the fact that Moon's induced variations of Earth surface are greater closer to Equator regions.

The proposed idea of magma transportation on vertical temperature gradient (with the help of Moon) seems to be new as well.
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reposted to http://divergent-boundaries.blogspot.com/
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