What about the previous glacial/interglacial periods in a regular cycle? (see post #16)
If it is crustal displacement, then what caused it to happen on a very regular interval cycle like this? External forces? Internal forces?
Hapgood's initial idea was that the ice build up around the pole(s) would be sufficiently imbalanced (as e.g. it is now in Antarctica) that the centrifugal forces would cause the shifts to occur where a new polar ice build up would begin that would eventually cause another shift. Apparently this idea has been discredited. Considering that Einstein accepted this mechanism a possibility, I'm not sure how discredited it could be. But no matter. We don't really need to know the mechanism to believe that it occurs. It's amazing to me how many things that have absurd explanations in Geology texts (e.g. mountain formation) can be simply explained by the crust shifting over the oblate core.
ML/NJ