Shake, shake, shake them bones.

[Ghoulish Delight]

Oops, forgot the links.

http://science.nasa.gov/headlines/y2...earthquake.htm

http://news.space-explorers.com/display.asp?v=3&i=1&a=1

I like this stat:

To make a comparison about the mass shifted as a result of the earthquake and its effect on Earth, Chao compared it to the great Three-Gorge reservoir of China. If filled, the gorge would hold 40 cubic kilometers (10 trillion gallons) of water. That shift of mass would increase LOD by only 0.06 microseconds and make the Earth only very slightly less oblate. It would shift pole position by about two centimeters (0.8 inch).

More of an effect than the sudden appearance of 10 trillion gallons of water would have. I'd say that's significant.