High Quality Content by WIKIPEDIA articles! The Chandler wobble is a small motion in the Earth`s axis of rotation relative to the Earth`s surface, which was discovered by American astronomer Seth Carlo Chandler in 1891. It amounts to 9 metres (30 ft) on the Earth`s surface and has a period of 433 days. This wobble combines with another wobble with a period of one year so that the total polar motion varies with a period of about 7 years.