n 1852, mathematician Joseph Adhemar suggested that the accumulation of thick ice at the poles periodically caused the earth to flip and the equator to move to where the poles were.
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.
The novel Geyserland: Empiricisms in Social Reform. Being Data and Observations Recorded by the Late Mark Stubble, M.D., Ph.D. (1908) by Richard Hatfield used the device of a fictional study to locate a blissful nation of pure Communism at the North Pole on the island of Atlantis. This fictional Utopia was destroyed by a pole shift set in 9262 B.C.
Hugh Auchincloss Brown, an electrical engineer, advanced a hypothesis of catastrophic pole shift influenced by Adhemar's earlier model. Brown also argued that accumulation of ice at the poles caused recurring tipping of the axis. identifying cycles of approximately 7 millennia.
Charles Hapgood is now perhaps the best remembered early proponent, from 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 model, speculated 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, he argued that each shift took approximately five thousand years, followed by 20 to 30 thousand year periods with no polar movements. Also, in his calculations, the area of movement never covered more than 40 degrees. His examples of recent locations for the North Pole include the Yukon Territory, Hudson Bay, and in the Atlantic Ocean between Iceland and Norway.[3]
This is an example of slow pole shift motion, which displays the most minor alterations and no destruction. A more dramatic view assumes more rapid changes, with dramatic alterations of geography and localized areas of destruction due to earthquakes and tsunamis. Several recent books propose changes that take place in weeks, days, or even hours,[4] resulting in a variety of doomsday scenarios.
Regardless of speed, the results of a shift occurring results in major climate changes for most of the earth's surface, as areas that were formerly equatorial become temperate, and areas that were temperate become either more equatorial or more arctic.
Hapgood wrote to Canadian librarian, Rand Flem-Ath, encouraging him in his pursuit of scientific evidence to back Hapgood's claim 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 wife, Rose.
Other theories which are not dependent upon polar ice masses include those involving:
* a high-velocity asteroid or comet which hits Earth at such an angle that the lithosphere moves independent of the mantle
* a high-velocity asteroid or comet which hits Earth at such an angle that the entire planet shifts axis.
* an unusually magnetic celestial object which passes close enough to Earth to temporarily reorient the magnetic field, which then “drags” the lithosphere about a new axis of rotation. Eventually, the sun's magnetic field again determines the Earth's, after the intruding celestial object “returns” to a location from which it cannot influence Earth.
* perturbations of the topography of the core-mantle boundary, perhaps induced by differential core rotation and shift of its axial rotation vector, leading to CMB mass redistributions. See, e.g., Bowin.[5]
* mass redistributions in the mantle from mantle avalanches or other deformations. See, e.g., Ladbury,[6] and Steinberger and O'Connell.[7]
[edit] Recent Research
Recent work by scientists and geologists Adam Maloof of Princeton University and Galen Halverson of Paul Sabatier University in Toulouse, France, indicates that Earth indeed rebalanced itself around 800 million years ago during the Precambrian time period.[8] They tested this idea by studying magnetic minerals in sedimentary rocks in a Norwegian archipelago. Using these minerals, Maloof and Halverson found that the north pole shifted more than 50 degrees — about the current distance between Alaska and the equator — in less than 20 million years. This reasoning is supported by a record of changes in sea level and ocean chemistry in the Norwegian sediments that could be explained by true polar wander, the team reports in the September–October 2006 issue of the Geological Society of America Bulletin.[9]
Research using GPS, conducted by Geoffrey Blewitt of the University of Nevada, has shown that normal seasonal changes in the distribution of ice and water cause minor movements of the poles.[10]
[edit] New Age Theories
The field has attracted many pseudo-scientific and non-scientific authors, offering a wide variety of things as evidence, including such things as psychic readings. Theosophic writer David Pratt[11] has put together a notable comparison of scientific views regarding pole shift compared to those of Theosophy.[12]
[edit]