Hi BW. There is quite a bit of information regarding the polar shifts, but I think this may be what you’re looking for.

You will note that the last time there was a polar shift which was about 780,000 years ago it was right around the same time Long Valley Calderas had its major eruption and also close to the same time Yellowstone had one of its major eruptions. Makes one wonder. Take Care…Don in creepy town

• Polar shifts