What is Driving the Continental Drift?post by Lymphatera · 2019-04-11T10:01:21.248Z · score: 10 (11 votes) · LW · GW · 9 comments
At some time in the early nineties of the last century But what are these forces? Which is too bad. While generally drifting eastward. 9 comments
At some time in the early nineties of the last century
- and after looking at a topographic map of continents and ocean floors on a wall of our home for some years, which was by then already thirty years old and had come into our possession as supplement to a National Geographic, or so I seem to remember; it was by Bruce Heezen and Marie Tharpe, who, as far as I know, had taken WW II submarine soundings of the ocean floors, mapped them out with their mid-ocean rifts, and combined these depictions, so I suppose, with the then equally new satellite images of the world into a unique work of art - it dawned on me that there was a remarkable coincidence of symmetry and asymmetry in the shape and distribution of the continental land mass - and, to a certain extent, and complementary to that, of the ocean floors.
Way back then and before, I was already a fan of Alfred Wegener's theory of continental drift, which was still being disputed at the time; and to be sure, the explanations as to what DROVE the continental drift - once you accepted it as fact - seemed wildly off to me as well, and completely incompatible with the topography of the world.
At least, that was the way I came to see it.
The symmetry in the continental shapes was that there are two types of them - one more or less circular (perhaps due to rotation?) and one more or less triangular (due to what?); and these shapes had become deformed in a specific way in certain places.
And then there was a more or less circular ocean - the Arctic - opposing one of the more or less circular land masses, Antarctica. As I was later to learn, almost ALL land masses lie opposite an ocean on the other side of the globe; and of course, vice versa. Think about it. What if this always was the case?
The asymmetry, on the other hand, lay therein that there is a distinct east-west and north-south asymmetry to be observed on the surface of this planet. Take a look at that map I mention above - or any other.
You will notice that:
1. There are continents more or less completely free of subductive or "border" mountain chains - Africa (except perhaps for the relatively confined Atlas mountains), Australia (do not mistake rift ridges for subduction) -
2. There are NO subduction zones to the EAST of continents - or on the north (referring to that continent under which this subduction is taking place) -
3. There are NO island chains or basins to the WEST of continents -
4. There exists a weird double triangular system, akin to spiraling vortexes, comprised of a) the recent alpide subduction mountain chain - from the Pyrenees and Alps to the Himalayas, there branching off to the Rocky and Andes mountain chains on the one and the Indonesian island chain on the other arm, together with the accompanying system of rifts and grabens; their hubs being the Central Asian mountain mass and, respectively, the three-way rift split under the Indian Ocean, which is - and this is important - positioned to the south and west of it, with others under the south Pacific and one under the south Atlantic.
Now, 150 million years after breaking up the last supercontinent Pangea, these still widening rifts, still rising subductive mountain chains, and earthquake-stricken island chains speak of the same forces that go on shaping the world in its present form.
But what are these forces?
Could they perhaps be traced, by observing their thrust?
The - then - more or less accepted view, that the continents were breaking up due to heat accumulation beneath them, leading to convection, seemed completely wrong to me; it might explain Australia, Africa and the East African Rift, being without subduction, yes, but not the Americas or Asia or even Europe, with their respective subduction zones; and where there were hot spots, they were in the wrong place, such as the pacific ocean, with no heat accumulation below it - due to this theory.
Furthermore, as this idea was being banded about, wild assertions were being made as to how and why, and in which direction, what plates and, oh, yes micro plates were moving; and these directions seemed to change with every earthquake event.
Then satellite tracking was introduced; and over the years, it, too, produced wildly inconsistent results, at least in the public domain - one difficulty being, of course, that, on a globe, there is no fixed point from which you can discriminately measure all movements in all direction. If two points are moving relative to one another, this has no bearing on their common or absolute movement, and so on.
But then, on a ROTATING globe there are two points of reference, aren't there? And with that, we can discern direction, too. And so we see that there is a continental pattern in relation to the Poles:
The string of triangular continents, North America, South America, Africa and India all point, more or less, west-east and south; and then there is the already mentioned the dual circular Arctic / circular Antarctic system with the quasi-circular continent of Australia near the latter. And I would count Eurasia in there as a large and strongly deformed circular continent; the deformation here being the important part to look for.
Rotation and direction may already be a hint, but it first serves simply as a system of reference, to be able to make some meaningful geographical statements relating to the surface of a globe.
Following these ideas, I tried to reverse the continental drift by successively and simultaneously closing the ocean rifts and expanding the respective subduction zones on some copies I had made of that map; and I found that, because of the location of the triangulated rifts in the Atlantic, but more importantly of the ones parallel to the Equator in the Pacific and the Indian Oceans, these, reversed together, quite openly forced a monodirectional movement; and, in combination with the closing of the island chains, these trials gave the distinct impression that the continents, in retracing their movements to their origins, were moving west; and therefore they had moved east in opening all these rifts and island chains, and subducting massive amounts of continental matter; and all of this ever since the breakup of Pangea.
In fact, I began to assume that the mass of continental matter subducted is far greater than I had imagined up to then; so that the Alpine mountain chain, together with the Central Asian mountain mass, both a few thousand meters high, is the expression of two continental plates sitting on top of each other at a very slight tilt; and that the same goes for the West of the North and South Americas; though not quite as much there.
Seen in that way, the African continental plate extends far into, and under, central Europe; and the former Indian plate is not only pushing up the Tibetan High Plateau, but has traveled far into, and under, what was once a rather circular southern Asian coast; thus squeezing China, and what was once called Indochina, out to the East.
What unbelievable forces were and are at work here? The mere bubbling of a cauldron of magma could never, in my mind, produce these titanic and directional thrusts.
The next hint I perceived, was, that the continental movement seemed to be more expressed along the Equator than over the Poles; in fact, these polar regions represented a kind of quietly spinning twin vortex in themselves.
The eerie impression was, indeed, that of a river; a massive, equatorial, magma stream, which was simply carrying the continents along.
A gigantic equatorial magma stream, dragging the lighter continents along on and over the surface of this planet? What in Jingen's name could induce such a thing?
And then this stream flows east, fastest along the Equator, almost nil at all at the Poles, and is overtaking the planetary rotation itself?
What, in heavens's name, lies below this mass of extremely viscous, molten rock, a few thousand of miles thick and weighing billions of tons, that is so strong, and so heavy enough, to drag a stream of magma along the Equator, in the same direction that the entire planet is rotating - only faster?
All it had to do for this, being heavier, was to rotate faster than the surface; but how much faster would the continents then be moving along? And how much faster on the Equator than at the Poles?
For that, I needed detail, age, and the precise direction of the assumed magma flow. The age of the ocean floors, for example.
Looking up what data I could find on the subject, on paper and on the then just beginning internet, I not only found that what I found matched my idea quite well - except for a few, in themselves quite fascinating details - I also found that the problem was just a bit more intricate than I had thought.
For, if the continental shelves were to be first torn apart and to then again collide, something had to not only accelerate certain parts of them, but something (else?) also had to hold other parts back - otherwise they would all just be trundling happily along, and no-one would be the wiser, as long as the travel was strictly equatorial.
But it quite obviously wasn't even being that.
I won't go into all the minute details here, but looking closely at the direction and the timelines on the ocean floor spreading markers, the proposed equatorial magma flow was not flowing along straight, but had a very marked sinus overlay to it, accounting for the northeastern movement of Africa and the southeastern movement of South America, for instance; and this seemed to mimic the ecliptic, or position of the noonday sun on the Earth - even if this position is not at all fixed.
Could it be that the Sun's gravity was working as a counterpart, holding back the surface of the planet, while the Earth's core, a gravitational unit of its own, was pushing things along from below? Well, that at least seemed possible...
Furthermore, it was not only the different speeds and spaces involved in the equatorial vs. polar regions; the magma flow seemed to have a third dimension to it as well: surfacing in the Darwin Rise of the Northwestern Pacific Basin, it burrowed down under the Americas' West, re-surfacing on the other side, under the Atlantic and under Africa, then burrowing down again under Eurasia, only to resurface again in the pacific Darwin Rise, that way closing the loop.
All of this, if true, would mean several things:
One, the mid-ocean ridges themselves are moving along to the east, while unfolding themselves, symmetrically, to both sides of their central rift; they, together with sea floor spreading, were not really the cause of continental drift, but rather a result. The same goes for the subduction zones; where ever continental shelves collide, they were - and are! - being massively deformed, far beyond just their actual compression zone; the thermal buildup and movement, until then taken as the cause for the continental drift, would also rather be a result.
Two, the lateral movement of the continents themselves, on this winding planetary conveyor belt, massively exceeds anything hitherto imagined.
For, taking into account the information that was available to me at that time, such as fossil evidence and other time markers, I estimated the extra movement of the continents on the surface of the planet to be around 20 cm true east along the Equator per year, which of course you would not see directly, as the Earth rotates in that direction. And it was at about half that speed, that this flow, for instance, ripped India, together with what now lies under Tibet(!) away from southern Africa, pulling it northwards far up into and under central Asia in just about 20 million years, simultaneously pulling northern Africa under Europe all the way to the Carpathian, Caucasian and Persian mountain ranges and slightly tilting it towards the North Sea; by that way opening the new Red Sea, Mediterranean Sea and adjacent basins.
Furthermore, using what I had about the relative movements of the continents, and combined with what I had deduced to be the speed of the assumed three-dimensional and sinusoidal west-eastern magma flow, I calculated that, when, what was once to become northern Italy / southern Germany started to emerge on what was, then, on and beyond the northeastern coast of a much larger than today proto-african continent, all of this was located somewhere near where Australia lies now - this having credibility in the findings of Archaeopteryx's surrounding environment - and that Africa, that seemingly stable continent, had traveled almost once around the world within that time frame - without suffering subduction itself, but being torn apart to the east instead.
And as I was to find out about ten years later, some scientists, who were doing research with seismic measurements at around the same time I was doing my superficial estimates, had found that the Earth's core is indeed superrotating - at about 1 extra revolution every millennium.
Which was very nice.
However, to this day, and as far as I know, no-one has made the connection to the continental drift.
Which is too bad.
Or has someone? I'm just too lazy to look it up by now...
I did, at that time, however, have some very friendly correspondence with scientists whose work I had looked up on the subject - on pulped wood, way back then - such as that of the geologists Neev & Hall, who had found, in their field research on the continents they had examined, such as, I seem to remember, Africa and the Middle East, that these seemed to have had been deformed massively over time, specifically including those continents without subduction zones; and not only that, these deformations came in the form of:
So imagine, if you will, two or perhaps three or more tornado vortexes of incredibly slow-moving magma swirling across this planet, powered and driven along by a superrotating Earth's core, all of which drive and drag as clouds before and behind them the continental shelves; and thus changing their shapes all the time.
While generally drifting eastward.
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