Pole flip?
Types:
1. Magnetic: which has occurred many times, of which I have my own semi-theory of the reasons why.
2. Tectonic: which confuses most. It's actually a rapid shift of the tectonic plates. The movie 2012 is based around this theory.
3. Actual shift of the earth's axis (poles if you will): Imagine a spinning top. As it slows it begins to wobble. Suddenly it darts off in some odd direction.
The earth spins in space and has an inherent wobble. The earth is so massive, rotation speed remains practically constant, but the wobble varies. Changes in wobble have to be made up somewhere. This is accomplished by minute variations in the tilt of the earth speeding up and slowing down.
I'm of the opinion that sometimes these adjustment periods can be considerable, leading to all matter of consequences, from a simple increase in earthquakes, to speeding up of tectonic shift, or perhaps even an unbalance of the earth's core in relation to the earth's crust.
The one thing we should know, is how much we don't know; about our very dynamic planet, and the world in which we live.
Another thing we don't know, is how much our governments know, but are unwilling to share with the general public.
We are due for another pole shift and the magnetic poles have been very erratic for a few years now. They have no idea what triggers this process so we will all have to wait to see, if we are still around that is.
An interesting possibility. It would indeed change the world.