mamooth
Diamond Member
but the main island of Japan moved 8 ft. east and the earth tilted slightly on it's axis.
No, it didn't. The tilt of the earth didn't change at all at the time of the earthquake, and it's only had an effect of a fraction of an inch since.
The earthquake changed the _figure axis_ by 8 inches. The figure axis is not the spin axis. The figure axis is the mass balance axis of the earth. Over the years, the ends of the spin axis slowly rotate around the ends of the figure axis. So, shifting the figure axis only means a very small change in the spin axis many years down the line. However, the figure axis is constantly changing anyways, now mostly due to isostatic rebound and ice loss in Greenland. The figure axis shifts due to earthquakes are small in comparison.