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Fraser
2008-May-14, 10:20 PM
Curved features on Jupiter’s moon Europa may indicate that its poles have wandered by almost 90°, a new study reports. Researchers believe the drastic shift in Europa’s rotational axis was likely a result of the build-up of thick ice at the poles. “A spinning body is most stable with its mass farthest from its [...]

More... (http://www.universetoday.com/2008/05/14/pole-shift-on-europa/)

iantresman
2008-May-14, 11:39 PM
Curved features on Jupiter’s moon Europa may indicate that its poles have wandered by almost 90°, a new study reports. Researchers believe the drastic shift in Europa’s rotational axis was likely a result of the build-up of thick ice at the poles. “A spinning body is most stable with its mass farthest from its [...]

More... (http://www.universetoday.com/2008/05/14/pole-shift-on-europa/)

Looks like this is sourced to an article in Nature:

"True polar wander on Europa from global-scale small-circle depressions (http://www.nature.com/nature/journal/v453/n7193/full/nature06911.html)",
Paul Schenk, Isamu Matsuyama & Francis Nimmo, Nature 453, 368-371 (15 May 2008)


I've also been trying to find who originated and developed the theory of true polar wander due polar ice build-up. Unless anyone else can indicate otherwise, I've found:


1852: "Joseph Adhemar (http://en.wikipedia.org/wiki/Joseph_Adhemar) suggested that the accumulation of thick ice at the poles periodically caused the earth to flip" (Wikipedia (http://en.wikipedia.org/wiki/Pole_shift_theory#Early_proponents)) But I haven't found a decent source.
1948: Hugh Auchincloss Brown (http://en.wikipedia.org/wiki/Hugh_Auchincloss_Brown) "claimed that massive accumulation of ice at the poles caused recurring tipping of the axis". See also Time Magazine, "Can the Earth Capsize? (http://www.time.com/time/magazine/article/0,9171,888482,00.html)", Sep. 13, 1948
1955: Thomas Gold, "Instability of the Earth's Axis of Rotation (http://www.nature.com/nature/journal/v175/n4456/abs/175526a0.html)", Nature 175, 526 - 529 (26 March 1955)
1958: Charles Hapgood (http://en.wikipedia.org/wiki/Charles_Hapgood)'s "polar shift theory" in his book Earth's Shifting Crust: A Key to Some Basic Problems of Earth Science (1958) with a forward by Albert Einstein
1978: Peter Warlow, "Geomagnetic reversals? (http://www.iop.org/EJ/abstract/0305-4470/11/10/026)", J. Phys. A: Math. Gen. 11 2107-2130, who suggests "The motion is classed as a fast precession, or nutation [..] the motion of a tippe top"