Others' Island (spoilers all books incl RWC)

['thul]

it could be on a separate tectonic plate, or far enough in on another one not to be affected. It could also be "protected" through alternate means like magic, though that is currently impossible to say. it would not appear that it really changed all that much in the plate positions during the RotE cataclysm, the main difference is that one plate (the cursed shore) was submerged, forcing the seas inwards. It could also be that on the far side of the same plate there is a giant glacier, for while much water is locked up in such, several hundred cubic kilometers of ice weigh quite enough to lower a tectonic plate, causing an sum rise in the sea level. The glaciers in the out islands are growing, so as such it would support ice age theory. It is after all only in the years leading up to and to the middle of an ice age that glaciers grow.

The cursed shore & duchies plate could very well stretch thousands of kilometers away from those two regions, leaving plenty of space for glacier(s) large enough to modify sea level. Considering that it takes many generations for wild species to loose a reflex (that to look up before entering a clearing), enough time could have passed to validate the establishment of an ice age.