Editing Polar motion (section)

== Analysis ==
Polar motion is defined relative to a conventionally defined reference axis, the CIO ([[Conventional International Origin]]), being the pole's average location over the year 1900. It consists of three major components: a free oscillation called [[Chandler wobble]] with a period of about 435 days, an annual oscillation, and an irregular drift in the direction of the 80th [[Meridian (geography)|meridian]] west,<ref name=IERS>{{cite web|title=Polar motion|url=http://www.iers.org/IERS/EN/Science/EarthRotation/PolarMotion.html|website=International Earth Rotation and Reference Systems Service|publisher=Federal Agency for Cartography and Geodesy|access-date=7 September 2015}}</ref> which has lately been less extremely west.<ref>{{cite journal|last1=Chen|first1=J.L.|last2=Wilson|first2=C.R.|last3=Ries|first3=J.C.|last4=Tapley|first4=B.D.|title=Rapid ice melting drives Earth's pole to the east|journal=Geophys. Res. Lett.|date=7 June 2013|volume=40|issue=11|pages=2625–2630|doi=10.1002/grl.50552|bibcode=2013GeoRL..40.2625C|doi-access=free}}</ref><ref name=Adhikari>{{cite journal|last1=Adhikari|first1=Surendra|last2=Ivins|first2=Erik R.|title=Climate-driven polar motion: 2003–2015|journal=Science Advances|date=8 April 2016|volume=2|issue=4|pages=e1501693|doi=10.1126/sciadv.1501693|pmid=27152348|bibcode=2016SciA....2E1693A|pmc=4846461}}</ref>{{rp|1}}