Dr. Benjamin Fong Chao, of NASA's Goddard Space Flight Center, Greenbelt, Md. and Dr. Richard Gross of NASA's Jet Propulsion Laboratory, Pasadena, Calif. said all earthquakes have some affect on Earth's rotation. It's just they are usually barely noticeable.
"Any worldly event that involves the movement of mass affects the Earth's rotation, from seasonal weather down to driving a car," Chao said.
Stop jumping! You're rocking the world!
It ain't me, I promise!