It is well known that the poles have often changed their position on the Earth’s surface during past geological eras. The marks left by thick ice sheets in Africa and India, the residual magnetism in ancient rocks, the old coral reefs’ and coal deposits’ distribution and so on, all together are compelling evidence that the poles have wandered from what is today’s equator to the actual poles.
Scientists attribute this “wandering” to the drift of continents and to the displacement of large quantities of materials, due to erosion and sedimentation processes, which in theory can provoke a very slow shift of the poles: a few centimetres per year at the most, but in hundreds of millions of years it can result in shifts of thousands of kilometres.
There is strong evidence, however, that this phenomenon could be much faster.
In his book The Path of the Pole (Chilton Books, Philadelphia, 1970) Charles Hapgood expresses the hypothesis that the poles have changed their position three times during the past 100,000 years. Between 50,000 and 12,000 years ago, at the end of Pleistocene, the North Pole was located somewhere around Hudson Bay, in Eastern Canada, and only 12,600 years it moved to its current position.
To support his thesis, Hapgood presents an impressive quantity of evidence which can be summarised as follows:
a) between 50,000 and 12,000 years ago an impressive ice cap, more than two miles thick, spread from the Hudson’s Bay area southward, down to the latitude of New York, and westward to join, at its maximum extent, glaciers flowing down from the Rocky Mountains, in Alaska. During the same period Northern Europe was covered by ice caps, which at their maximum extent reached the latitude of London and Berlin. The quantity of water trapped in these ice sheets and in the glaciers scattered around the world was so large, that the sea level was about 130 meters lower than today.
b) The current “scientific” explanation for the existence of these ice caps is that they were due to a cooler climate all over the world. But this theory is contradicted by the absence, during the “Ice Age”, of ice sheets in Siberia, which was actually populated, up to its northernmost regions, by one of the most impressive zoological communities of all times. Millions (more than 40 millions, according to F.C. Hibben) of mammoths roamed Siberia and Alaska. Animals as large as this can be found today only in tropical regions, or in other areas where the supply of fodder is guaranteed all the year round.
It is counter-intuitive that during the Ice Age one of the largest zoological communities since the dinosaurs existed in those very areas which are today regarded, due to their extreme climatic conditions, as amongst the most hostile on Earth. With the mammoths there were dozens of other animal species, the majority of which are extinct today. Of these species we have a great number of skeletons, several complete animals that have been perfectly preserved in the permafrost, and many wonderful paintings in Palaeolithic caves. The oldest amongst the latter is Chauvet cave, in France, parts of which were painted as early as 33,000 years ago. It contains paintings of breathtaking beauty. The unknown artists, with a few strokes, have represented to perfection animals which at the time were living in the plains of central Europe (and at the same time in Siberia and Alaska) . But the beauty of the paintings makes the zoologist wonder in more ways than one. How could such a varied assembly of animals coexist? To what bizarre ecological environment could such a motley fauna belong? We find the reindeer next to rhinoceros, the mammoth, with its woolly mantle, near the hippopotamus, lions side by side with bears, leopards and Przewalski horses. There are also giant beavers and sloths, big-horned deer, camels, sabre-tooth tigers, buffaloes, aurochs, and many other species.
It’s an incredible mixture which leaves us puzzled and astonished. Arctic and tropical fauna together, on the same plain, in perfect balance with the environment! Such an extraordinarily varied and numerous animal community – the like of which can be found nowhere on Earth today – seems to challenge current opinion on climatic conditions during the Ice Age. Moreover, this community suddenly disappeared when the Ice Age ended – exactly at the moment when, according to modern theories, climatic conditions were supposed to have become milder and more supportive of life. This mysterious, now-vanished fauna populated the Siberian islands well inside the Arctic Sea; their remnants can be found on islands located at only 1000 km from the north pole, and in the same islands rock engravings have been found. This suggests strongly that in the late Pleistocene (a period during which global climate was supposedly much colder than it is today, especially at the high latitudes) the Arctic Sea was in fact much warmer than it is today.
c) On the other side of the world, climate was cooler in Australia and New Zealand, then partially covered by large glaciers. But there is solid evidence that Antarctica, now completely covered by a thick layer of ice, must then have been partially free of it. Sediment cores collected during Admiral Byrd’s expedition in the Ross sea in 1947-1948, and later by Glomar Challenger in the Weddell sea, show that in the late Pleistocene large rivers must have flowed in these parts of Antarctica. Again, is this not a strong suggestion that the climate of Antarctica must have been much milder during the “Ice Age” than it is even today -- despite the intense global warming experienced in the last century?
A shift of the poles, occurring around 11,500 years ago, could explain completely and coherently the climatic situation before that date, and the situation that came into being after that date.
On the possibility of instantaneous shifts of the poles
The hypothesis that the inclination of the terrestrial axis in relation to the ecliptic – and thus the position of the poles – might change first began to be given serious consideration during the 19th century. Some of the greatest scientists of the time, including J.C.Maxwell and Sir George Darwin (son of the famous Charles Darwin), considered this problem and decided that the stabilising effect of the equatorial bulge was so great that no conceivable force could make the Earth shift on its axis, except for a collision with another planet. They therefore dismissed the idea of any shift of the poles as impossible and, in fact, not worth discussing. Their influence has been so strong that to this day no one has seriously contemplated such an hypothesis again.
Hapgood too accepts un-critically the assumption that only a “planetary collision” is capable of displacing the axis of rotation. Therefore he proposes a theory that explains the shift of the poles as the result of the shift of the whole Earth’s crust. Based on the research of the Russian scientist V.V. Beloussov, he assumes that at a depth of approximately hundred miles in the upper mantle there is a layer of liquid rock which behaves as a bearing allowing the whole crust to “shift” when subjected to a displacing force. In Hapgood’s opinion this force is provided by the centrifugal momentum of ice caps positioned eccentrically with respect to the poles. In this way the Earth would keep its axis of rotation unchanged, but the poles and the whole Earth’s surface would shift and change latitude.
The evidence proving that the poles where in different positions during the Pleistocene era is quite impressive, and this explains why Hapgood’s theory was approved by scientists of the calibre of Einstein and K.F. Mather. But it meets with so many difficulties that it appears highly controversial. Above all, it is not compatible with other geological theories which are widely accepted today, notably plate tectonics and continental drift.
Furthermore the theory does not explain some of the key peculiarities of the climate changes of the late Pleistocene – most significantly the speed with which these changes appear to have taken place. According to Hapgood’s theory it took the north pole at least two thousand years to move from its previous position to the present. The evidence we have, however, supports a much faster climatic change. It was Hapgood himself who underlined the enormous amount of data proving the high speed at which the shift of the poles appears to have happened; yet the mechanism he proposes does not explain this speed.
It appears that we can explain completely and coherently what took place at the end of Pleistocene by admitting the possibility of a shift of the poles of the same magnitude Hapgood hypothesises, but in a much shorter time: not more than a few days. This possibility is generally rejected because no convincing explanation for such a phenomenon has been brought forward so far. According to scientists, the only way to make a planet change its axis of rotation is that of “adding” to it a mass comparable to its own. But it is my view that at least one other way exists, one that has not been considered yet -- that of “re-shaping” its equatorial bulges around a different axis.
If Earth was a perfectly rigid and spherical body, a single man walking on its surface could make its poles shift. In fact, the stability of the Earth is provided only by its equatorial bulges, some 12 km thick, very small with respect to the Earth’s radius. Move the equatorial bulges and the poles will move accordingly. Impossible? Not really, if you consider that two thirds of Earth’s surface is covered with water; and every naval engineer knows that free liquid surfaces induce instability (experience shows that a simple tsunami is enough to make the poles shift of by measurable amount). Let’s see how this instability can result in a wide and permanent shift of the poles.
The Apollo objects
Severe consequences can follow when the Earth is hit by a comet or an asteroid. We know for certain that this happened many times in the past and can happen again any moment in the future.
If the Earth didn’t have oceans and atmosphere its surface would be marked with huge numbers of craters like the Moon and Mercury . On our planet, instead, erosion and sedimentary processes very quickly erase the traces of collisions with asteroids, meteorites and comets. Only where recent ice sheets have scraped the surface, thus uncovering the traces of ancient collisions as in parts of Canada, is it possible to count the craters accurately. Based on this approach G.W. Wetherill (see: G.W. Wetherill, “The Apollo Objects”, Scientific American May 79) has estimated that in the last 600 million years our planet has been hit by at least 1500 objects with a diameter larger than one kilometre.
The majority of these collisions is caused by a class of celestial bodies named by astronomers “Apollo objects”, that is a class of asteroids whose perihelion lies inside the orbit of the Earth. The first of these objects was discovered by Reinmuth on 1932 and named Apollo, which gave the name to the class. At present, more than one hundred Apollos of a diameter of at least one kilometre are known. The largest discovered so far, Hephaistos, has a diameter of ten kilometres. The total number of Apollo objects with a diameter of one kilometre or more is estimated to be between 1,000 and 2,000.
As the perihelion of the Apollos lies inside the orbit of the Earth, it follows that periodically they have the chance to collide with it. The probability of such an event is estimated at 5. 10-9 per year per single Apollo. Therefore we have a probability of at least 4 collisions each million year period with objects as large as one kilometre or more. As the size of the objects becomes smaller, this probability grows exponentially to reach one impact every few centuries for objects of 100 to 200 metres diameter.
The direct effects of a collision with an Apollo-like object are devastating. Gehrels (see:Tom Gehrels, “Collision with comets and asteroids”, Scientific American, March 96) estimates that a one-kilometre-wide object, colliding with the Earth at a speed of 20 kilometres per second, would liberate an energy equivalent to ten billion Hiroshima-type nuclear bombs.
How the poles can shift
Scientists are trying to understand what could be the overall effect on the Earth of a collision with an Apollo object. The scenarios they have come up with so far look rather dire. After all, many believe that the extinction of the dinosaurs followed an impact with an asteroid. None of these scenarios, however, has taken into consideration the possibility that such an impact could also provoke an almost instantaneous shift of the poles. This is because, compared to the Earth a one-kilometre-wide asteroid is like a tiny sphere of 2 millimetres next to a ball of 25 meters. Its mass is absolutely negligible. The displacement of the poles due directly to it, if any, can be measured in the order of centimetres.
What can not be neglected, however, is the torque provoked by the impact. Due to the very high speed of the asteroid, the impulsive torque it delivers can be of sufficient magnitude to overcome, for an instant, the reaction torque developed by the Earth. The instant may, in itself, be too short to produce any measurable effect; yet I will argue that it can trigger a process that in the end results in a change of the axis of rotation.
Let’s see how.
Earth is a gyro. A gyro subject to a disturbing force reacts with a movement called “precession”. Unfortunately the precession phenomenon has been studied exhaustively only for the case when the precession’s rotation is much smaller than the gyro’s main rotation, the only interesting case for technical applications. Scientists, therefore, are not familiar with the case in which the two rotational components have the same order of magnitude. This case is examined here in the appendix, where the behaviour of a gyro subject to a disturbing torque of increasing value is shown. It appears that when the torque reaches a critical value, equal to the maximum reaction torque that can be developed by the gyro, the latter changes its axis of rotation permanently. The new axis, which coincides with the previous precession’s axis, is maintained even if the disturbing torque diminishes again, as long as its value is higher than zero. Only if and when the torque is completely null (or becomes negative), does the gyro recovers its previous rotational axis.
The behaviour of the Earth when subjected to a disturbing torque is obviously the same. In fact the Earth has a movement of precession due to the disturbing torque exercised by the Sun-Moon gravitational attraction on the equatorial bulges. This torque is one million of times smaller than the maximum reaction torque which can be developed by Earth. Simple calculations, however, allow us to establish that an object as small as a half-kilometre-wide asteroid, hitting the planet in the right spot and at the right angle, is capable of developing an impulsive torque of the same magnitude of the maximum Earth’s reaction torque. In this case the Earth assumes, for a very short instant, a different axis of rotation.
If at the moment of the impact the force of the Sun-Moon gravitational attraction on the equatorial bulge has the same direction as the force developed by the impact, a shift of the poles will inevitably follow. Immediately after the impact, in fact, the torque should go down to zero, and the Earth should recover its previous rotational axis. But if the torque exerted by the sun-moon attraction has the same direction, the torque cannot be zeroed and therefore the Earth keeps “memory” of the impact and of its direction. This “memory” consists of an extremely small rotational component, with the same direction as that of the impact, in the order of 1 millionth of the normal rotation. What is particular in this rotational component is that it is fixed with respect to the Earth. If the latter was a solid gyroscope, this situation would last indefinitely unchanged. The planet, however, is not homogenous and rigid. First of all it is covered by a thin layer of water, which reacts immediately to any change of motion. Second, even the “solid” outer shell is in reality plastic and can be easily “re-shaped” by centrifugal forces.
Under the effect of this tiny rotational component, sea water begins to move towards a circle perpendicular to that rotation (the new equator). This is a very small effect, and if it was the only component, the resulting equatorial bulge would be of a few meters only. But as this happens, the value of the rotational component increases, at the expense of the main rotation, therefore increasing the centrifugal force which makes more water move towards the new equator, thus increasing the force and so on. This process starts very slowly, but accelerates progressively, until the centrifugal force developed by this rotational component grows strong enough to induce deformations of the Earth’s mantle.
From here on the equatorial bulge is quickly “re-shaped” around the new axis of rotation and Earth will soon be stable again, with a different axis of rotation and different poles.
This mechanism shows that the Earth’s poles, contrary to what has always been postulated, can make “jumps” in a matter of days (that is almost instantaneously) of thousands of kilometres, due to the effects of forces at first sight negligible, such as the impact of a medium-size asteroid and the Sun-Moon gravitational attraction on the equatorial bulge, combined with the effects of water mobility and the plasticity of the crust.
Phenomena which happen during a shift of the poles
Suppose the Earth has been hit by an asteroid and that the conditions to trigger a shift of the poles have been met. On the basis of the adjustments necessary to re-shape the equatorial bulge around the new axis of rotation, and the consequent reestablishment of the isostatic equilibrium of the crust, we can predict what kind of phenomena would happen on the surface.
Some areas of the Earth’s crust would be driven to move upward, others downward. The up and down movements necessary to re-shape the bulge would be different from site to site. For a shift of 20o, for example, the movements would be of three or four kilometres at the most. Very small, compared to the diameter of the Earth, but nonetheless of great consequence on the surface. We know that the mechanisms which maintain the isostatic equilibrium of the crust are very effective; so there is no doubt that after a while the equilibrium would be re-established around the new axis of rotation, with poles and equator in different positions.
It is important to evaluate how long it would take for this to happen. We know that the layers of the crust, when subjected to a force over a certain limit, break suddenly, causing an earthquake. In the situation we have hypothesised, at the beginning only sea water would be displaced, with a gradual increase of the speed of rotation around the new axis. When the rotational speed reaches a certain critical value, sudden adjustments of the crust would begin to happen and from that moment the process would be sharply accelerated and the reshaping of the bulge would be completed in a very short time.
How short? Weeks, days or hours? Impossible to say. A simulation with a mathematical model should give reliable results. The process of reshaping the equatorial bulge should follow a course of exponential type: after the initial sharp peak, it should decrease very quickly. Adjustment phenomena, however, are expected to continue for a long time, as the isostatic equilibrium is reestablished more and more accurately.
Obviously, readjustments of that size of the equatorial bulge cannot happen without causing extensive fractures of the crust, which would provoke earthquakes of such a tremendous magnitude as to dwarf the most devastating known today. A sudden incredibly strong burst of volcanic activity in all areas subjected to strain would also be inevitable.
The beginning of adjustments of the crust would start not only earthquakes and volcanic activity. On the whole the oceans’ water and the atmosphere follow the rotational movement of the Earth, but they are not tied to it. If the Earth should suddenly change the direction of its rotation, they would, at first, thanks to their inertia, keep up their previous motion, thus provoking a dreadful hurricane all over the continents, with violent winds and torrential rains. The continents would be swept by hurricane force winds, reaching speeds of hundreds of kilometres per hour. Only after a while the attrition with the Earth’s surface would force them to follow the new movement.
The water of the oceans would play a much greater destructive role. We must expect wide fluctuation of sea levels in many parts of the world. Presumably an enormous tide, hundreds of meters high, would slowly move around the globe.
The same reasoning applies where the centre of Earth is concerned, consisting of a solid core, surrounded by a liquid layer of iron. This would at first continue in its motion, naturally undergoing strong attrition in the mantle boundary region, that would create turbulence which might have important effects. According to the latest theories, the liquid iron layer is the site of electrical currents, that are responsible for the earth’s magnetic field. This turbulence could provoke perturbation in the magnetic field that might lead even to an inversion of the magnetic poles.
An important element in order to evaluate the climatic conditions following a shift of the poles, is the inclination (tilt) that the new axis of rotation will assume with respect to the ecliptic. This has a tremendous effect on the climate. According to the mechanism we have spelt out so far the axis of rotation that the Earth would acquire at the moment of impact should be parallel to the direction of the hit. It is impossible to predict which would be the actual direction of the new axis once stabilised. It is certain that it would not be the same as the previous one, except for a fortuitous chance. Therefore, following a shift of the poles the course of the seasons would very likely be different.
For example, on the hypothesis that the axis of rotation is almost vertical with respect to the ecliptic, there would be an enormous growth of ice at high latitudes and altitudes, with subsequent lowering of sea level. On the other hand the climate would be much more stable then it is today, with very limited (or non-existent) seasonal climatic differences and an uninterrupted growth of vegetation. This would bring about the disruption of today’s climatic barriers, with subsequent spreading of tropical species towards northern regions and viceversa. There would also be the maximum possible development of ecological communities.
This appears to be exactly the situation that existed in the Pleistocene era, when imposing zoological communities thrived at the very edge of polar ice caps. And the phenomena which put an end to this situation appear to be exactly the same we have described.
The 10th millennium B.C. appears to be critical under several aspects. It was precisely in that period that the Palaeolithic cultures, which had thrived for more then 30 millennia, all of a sudden disappeared. And all over the world, both in land and at sea, there is appalling evidence of mass extinctions of animal species.
A geological era, the Pleistocene, came to an end, marked by a stunning burst of volcanism and by dreadful earthquakes, witnessed by the collapse of the vault in most caves all over the world. Even the magnetic field underwent serious challenges and nearly inverted. Not to speak about the climate which from then on went through a radical change.
12000 years have elapsed since then, a period that is only twice the length of the historical period. We are the direct descendants of men who managed to survive those cataclysms. Is it possible that the memory of events of that kind has been completely cancelled in such a relatively short time? Myths and legends about an apocalyptic disaster, which marked the “beginning” of humankind – the “universal flood” – are common to almost all populations of the world. Some of those legends, starting from Plato’s, report not only the same kind of phenomena we have described, but even the same date.
Is this only a mere coincidence or are they referring to the phenomena that put an end to the Pleistocene era only 12 thousand years ago? If we consider that a tiny asteroid can provoke an almost instantaneous shift of the poles, the second alternative looks definitely the most likely.
n Charles Hapgood, “The Path of the Pole”, Chilton Book Co, Philadefphia, 1970
n R. F. Deimel, “Mechanics of the Gyroscope. The dinamics of Rotation”, Dover Edition, 1950
n G.W. Wetherill, “ The Apollo objects”’Scientific American, May 79
n Tom Geherels, “Collision with Comets and Asteroids”’ Scientific American, March 96
n E. Spedicato, “Apollo objects, Atlantis and the deluge: a catastrophical scenario for the end of the last glaciation”, Quad. 90/22, 1990, Bergamo University, Italy