There are many theories. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
I'm not sure how the axial orientation of the earth would have that much of an effect. Unless the magnetic poles shifted. Is that what you mean Beany?
Changes in the ocean current are a good theory. Meteors, solar activity and volcanic eruptions are others.
Not the orientation is changed..
Euh how i'm going to explain this <img src="/ubbthreads/images/graemlins/silly.gif" alt="" />
The axis of the earth is simply an imagnary line that goes from 1 pole true the middle of the aerth true the other pole. (or something like that)
now this axis isn't a strait line . So not in a perfectly vertical position like the letter "I" but its has a small angle like the letter "
I " in italics.
now this axis doest stand still eiter. It has its own rotation itself too!
imagian to hold 1 end of the axis in your hand .Then the upper end of this axis will do a circular movement .
like these artists who have a ceramic plate ballancing in a stick in the circus. these sticks have somewhat the same movement.
This happens somewhat everery 20.000 years.(educated gess of the scientists)
if this axis rotates ->the angle of the sun changes in the same location. its like if the equesior (spelling?)(that goes true africa , amazones etc..) will move downwards.
the artics area wil move also somewhere into the region of europe..
and whe got another ice age
voila <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />