Plate tectonics linked to magnetic reversals

Scientists in France believe they have established a link between plate tectonics and magnetic reversals.


Position of continents at: (a) present time, (b) 65 million years ago, (c) 200 million years ago, (d) 260 million years ago. (Courtesy: François Pétrélis et al.)

Publishing their findings in Geophysical Research Letters (16 Oct 2011) the researchers, from Ecole Normale Supérieure, CNRS, and Institut de Physique du Globe in Paris, argue that the frequency of magnetic field reversals has depended on the distribution of tectonic plates on the surface of the globe (the earth’s mantle) during any given geological period.

Their modelling shows that more reversals occur when there is an asymmetry, when there is more landmass in one of the hemispheres than the other, which occurs on a timescale of roughly 100 million years.

Some 200 million years ago, Pangaea, the supercontinent that encompassed almost all of the Earth’s land masses, began breaking into a multitude of smaller pieces that  shaped the Earth as we know it today. By comparing the surface area of continents in the Northern hemisphere to those in the Southern hemisphere, the researchers were able to calculate a degree of asymmetry (with respect to the equator) in the distribution of the continents during that period.

The amount of asymmetry has varied at the same rhythm as the magnetic reversal rate (number of reversals per million years). The two curves  evolved in parallel to such an extent that they can almost be superimposed. In other words, the further the center of gravity of the continents moved away from the equator, the faster the rate of reversals.

The scientists envisage two scenarios.

In the first scenario, terrestrial plates could be directly responsible for variations in the frequency of magnetic reversals: after plunging into the Earth’s crust at subduction zones, the plates could descend until they reach the core, where they could modify the flow of iron.

In the second scenario, the movements of the plates may only reflect the mixing of the material taking place in the mantle and particularly at its base. In both cases, the movements of rocks outside the core would cause flow asymmetry in the liquid core and determine reversal frequency.

The title of this paper – “Plate Tectonics May Control Geomagnetic Reversal Frequency” – implies that tectonic plate movement triggers the increase in magnetic reversals, but I think they have it backward.

As I say in “Not by Fire but by Ice,” I think electromagnetic forces drive the plates, not the other way around.


See also:

See also:

Thanks to Owen, Kay Garden, Wanda  and Peter Lamb for these links

More information: Plate Tectonics May Control Geomagnetic Reversal Frequency. F. Pétrélis, J. Besse, J.-P. Valet. Geophysical Research Letters, 16 October 2011.

12 thoughts on “Plate tectonics linked to magnetic reversals”

  1. I have doubts about the diagrams above because of the Hawaii Emperor seamount chain and its extension north of the Aleutian trench that follows the Bowers ridge and goes north and crosses the Chukotka region and goes by Wrangel island and follows the Alpha ridge to Ellesmere island and Greenland. Mantle plumes don’t move much if at all but the crust above them does. The hot spot track may be more than 8500 miles long and represent a journey through time between 156 and 525 million years or more. North America rotated clockwise 90 to 120 degrees and in the process the south pacific rift fault plastered micro plates and terranes up against north america and pushed the continent clockwise in the process. If I had to take a guess the Bowers ridge north of Kiska got its shape due to massive warping of the crust just before the Aleutian trench formed. Afterward the oceanic plate subducted on an angle pushing the hotspot track under the plate and westward for more than 1500 miles which is why the track appears to go under the Kamchatcka peninsula instead of under Kiska. The continental rotation also explains mesozoic and paleozoic fossils and oil and gas deposits in the Arctic regions of Canada, Alaska and Siberia. I always thought the cold adapted dinosaur theory put forward to explain the fossils in Alaska was a bit of a stretch.
    Check it out on Google Earth. Right now the pacific plate moves at roughly 3.5 inches per year. Take the measurements and do the math.
    Pretty incredible hypothesis isn’t it?

  2. Personally, I lean towards the expanding Earth theory. It makes a lot of sense even if it flies in the face of a lot of perceived science. Much of science is, after all, interpretation of things that we can see but not necessarily prove, and I don’t think mathematical explanation is proof. Still waiting on the results of the faster than light test. Any one hear if it was duplicated or not?

    • No but its impossible to transverse – go through the light cone in Minkowski space into nowhere need negative mass. Light is invariant as is NOT a velocity it is a 4-hypersurface! Then it is invariant.

  3. The Gravity Theory of Mass Extinction, which pre-dates this study by many years has already predicted the relationship between continental plate distribution and movement of the Earth’s core elements.

    When the center of mass of the continental plates moves latitudinally, the Earth’s angular momentum would change. Yet, we know the Law of Conservation of Angular Momentum will not allow this.
    Therefore the Earth’s core elements (inner/outer cores and densest part of lower mantle) move off of center affecting not only magnetic reversals but also altering surface gravity. This explains dinosaur gigantism as well as many other Mesozoic conditions.

    • —‘this explains dinosaur gigantism…’

      So glad someone has come up with an explanation as it’s bothered me since I was a child.

      When my daughter was 7 and, like all kids, mad about dragons and dinosaurs (which she thought were the same), I mused that it was strange that following the dinosaurs, animals were never as big again.

      She came up with another explation: “I expect God thought ‘No, too big, rub them out and start again.'”

  4. Just ignore the “ocean” space on picture (d) and continue folding the continents into the sphere.

    You will stop with the new planet wich is smaller than the Earth (1/2 of the current radius) and has no oceans.

    This is how it could have been long time ago:
    – radius of 50% of the current;
    – solid rock with almost no water on surface;
    – earthday of just 7 hours
    – gravitation two times stronger;

    And then it started to expand.

    All these follows from the

    And what about reversals, I dunno.

  5. @Megapixel – I’m not familiar with the Gravity Theory of Mass Extinction you mention, and don’t have facilities to look it up at the moment. However, can I just check that you are saying that the theory holds that dinosaurs were big because gravity was significantly less than at other times?

    • @Jeremy,
      Yes, surface gravity was different when dinosaurs existed, according to the theory mentioned. When Pangea consolidated in the late Permian, surface gravity was at its lowest. Dinosaurs made their appearance after that and grew to their exceptional size through the Triassic and Jurassic Periods. When the continents split apart and moved latitudinally and longitudinally, surface gravity increased dooming the dinosaurs as well as all seagoing reptiles and other forms such as ammonites. All of those creatures evolved in a low gravity environment and became extinct about 65-70mya. There is much supporting evidence of this. GTME also posits that the 2 main superchrons, extremely long periods when there were no magnetic reversals, were the result of the movement of the core elements.

  6. The idea of continental drift and landmasses having fit together in the distant past doesnt make sense for several reasons.

    One simple reason is that rates of erosion by wind and water would have greatly altered the shape and sizes of land masses over such a long period and present continents would not have existed 200 million years ago. The British isles are expected to have eroded away completely in less than 300 thousand years from today.

  7. “The scientists envisage two scenarios.”

    I envisage three sceanrios, and the third is called coincidence.

    • @Gator,
      As stated earlier, there is another scenario. The Gravity Theory of Mass Extinction (GTME) posits movement of the core elements in response to the latitudinal assymetry of the continents….which would have to affect the flow of molten iron in the outer core.

      The two scenarios stated appear to be guesses. If plates infringed on the outer core, the assumption is that they managed not to be absorbed by the mantle, which gets hotter and denser deeper. I don’t know if there is any proof that the subducted plate can survive that deep journey. Secondly, the researchers don’t provide any explanation for synchronization between continental assymetry and plates reaching the outer core.

      This is why I believe GTME provides the better explanation for magnetic reversals.

  8. This fits quite well with Mr. Felix’s theories that he expounds upon in his books and also with plasma cosmology.
    There are four primary forces in the universe: weak nuclear, strong nuclear, gravity and electromagnetism. Of the four, electromagnetism is, hands down, the strongest over the broadest range. Gravity is so pathetically weak that any refrigerator magnet can overcome it. Electromagnetism is some 39 orders of magnitude stronger. That’s 1,000,000,000,000,000,000,000,000,000,000,000,000,000 stronger. Why wouldn’t a magnetic reversal have much more effect, as well as much quicker,than a gravity based plate tectonic event? Try pushing 2 bar magnets together. Take one of those same bar magnets and try to pick up a paper clip. You just overcame gravity very,very near it’s source. What makes more sense?

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