Jul 31, 2016
In the US, we have revised our geodetic datum over the yearrs. Most famously the switch from NAD27 to NAD83 as instrumention necessitated more measurements and resulted in a more accurate model. But in Australia, they are creating a new datum because the continent is MOVING 7cm a year.
Read here: http://www.bbc.com/news/technology-36912700
Check it:
The Geocentric Datum of Australia, the country's local co-ordinate system, was last updated in 1994. Since then, Australia has moved about 1.5 metres north.
So on 1 January 2017, the country's local co-ordinates will also be shifted further north - by 1.8m.
The over-correction means Australia's local co-ordinates and the Earth's global co-ordinates will align in 2020.