The cataclysmic pole shift hypothesis is the conjecture that there have been rapid shifts in the
relative positions of the modern-day geographic locations of the poles and the
of rotation of a planet. For the Earth, such a dynamic change could create calamities such
as floods and tectonic events. This type of event
would occur if the physical poles had been or would be suddenly shifted
with respect to the underlying surface over a geologically short time frame.
This hypothesis is almost always discussed in the context of Earth, but other bodies in the Solar System may have experienced axial
reorientation during their existences.
Among the scientific community, there is no research that indicates a rapid
change in the position of the rotational axis. There is evidence of precession and changes in axial tilt, but this change is on
much longer time-scales and does not involve relative motion of the spin axis
with respect to the planet. However, in what is known as true polar wander,
the solid Earth can rotate with respect to a fixed spin axis. Research shows
that during the last 200 million years a total true polar wander of some 30° has
occurred, but that no super-rapid shifts in the Earth's pole were found during
this period. A
characteristic rate of true polar wander is 1° per million years or less. Between
approximately 790 and 810 million years ago, when the supercontinent Rodinia existed, two geologically-rapid phases of true
polar wander may have occurred. In each of these, the Earth rotated ~55°
The geographic poles of the Earth are the points on
the surface of the planet that are intersected by the axis of rotation. The
pole shift hypothesis describes a change in location of these poles with
respect to the underlying surface – a phenomenon distinct from the changes in
axial orientation with respect to the plane of the ecliptic that are caused by
precession and nutation.
Pole shift hypotheses are not to be confused with plate tectonics, the well-accepted geological
theory that the Earth's surface consists of solid plates which shift over a
fluid asthenosphere; nor
drift, the corollary to plate tectonics which maintains that locations of
the continents have moved slowly over the face of the Earth,
resulting in the gradual emerging and breakup of continents and oceans over
hundreds of millions of years.
Pole shift hypotheses are also not to be confused with geomagnetic
reversal, the periodic reversal of the Earth's magnetic field (effectively
switching the north and south magnetic poles). Geomagnetic reversal has more
acceptance in the scientific community than pole shift hypotheses.
An early mention of a shifting of the Earth's axis can be found in an 1872
article entitled "Chronologie historique des Mexicains" by Charles Étienne Brasseur
de Bourbourg, an eccentric expert on Mesoamerican
codices who interpreted ancient Mexican myths as evidence for four periods
of global cataclysms that had begun around 10,500 B.C.
In 1948, Hugh Auchincloss Brown, an electrical
engineer, advanced a hypothesis of catastrophic pole shift. Brown also argued
that accumulation of ice at the poles caused recurring tipping of the axis,
identifying cycles of approximately seven millennia.
In his controversial 1950 work Worlds in Collision, Immanuel
Velikovsky postulated that the planet Venus emerged from Jupiter as a comet. During two proposed near approaches in about 1,450
B.C., he suggested that the direction of the Earth's rotation was changed
radically, then reverted to its original direction on the next pass. This
disruption supposedly caused earthquakes, tsunamis, and the parting of the Red Sea. Further, he said near misses
by Mars between 776 and 687 B. C. also
caused the Earth's axis to change back and forth by ten degrees. Velikovsky
supported his work with historical records, although his studies were mainly
ridiculed by the scientific community.
is now perhaps the best remembered early proponent. In his books The Earth's
Shifting Crust (1958) (which includes a foreword by Albert Einstein who was
writing before the theory of plate tectonics was developed) and Path of the Pole (1970). Hapgood, building on Adhemar's much earlier
that the ice mass at one or both poles over-accumulates and destabilizes the
Earth's rotational balance, causing slippage of all or much of Earth's outer
crust around the Earth's core, which retains its axial orientation.
Based on his own research, Hapgood argued that each shift took approximately
5,000 years, followed by 20,000- to 30,000-year periods with no polar movements.
Also, in his calculations, the area of movement never covered more than 40
degrees. Hapgood's examples of recent locations for the North Pole include Hudson Bay (60°N, 73°W) , the
Atlantic Ocean between Iceland and Norway (72°N, 10°E) and Yukon (63°N, 135°W).
However, in his subsequent work The Path of the Pole, Hapgood conceded
Einstein's point that the weight of the polar ice would be insufficient to bring
about a polar shift. Instead, Hapgood argued that the forces that caused the
shifts in the crust must be located below the surface. He had no satisfactory
explanation for how this could occur.
Hapgood wrote to the Canadian librarian, Rand
Flem-Ath, encouraging him in his pursuit of scientific evidence to back
Hapgood's claims and in his expansion of the hypothesis. Flem-Ath published the
results of this work in 1995 in When the Sky Fell co-written with his
True polar wander, or the motion of the solid Earth with respect to a fixed
spin axis that causes the spin axis to lie over a new geographic position, does
occur. This is because of changes in mass distribution throughout the Earth that
modify its moment of inertia tensor. The Earth
consistently readjusts its orientation with respect to its spin axis such that
its spin axis is parallel to the axis about which it has its greatest moment of
readjustment is very slow. In 2001, historical evidence for true polar wander
was found in paleomagnetic data from granitic rocks from across North America.
The data from these rocks conflict with the hypothesis of a cataclysmic true
polar wander event. This evidence indicated that the geographical poles have not
deviated by more than about 5° over the last 130 million years. More rapid past
possible occurrences of true polar wander have been measured: from 790 to 810
million years ago, true polar wander of approximately 55° occurred twice.
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