At http://phys.org/print398016399.html … Australia shifts and tilts back and forth by several millimetres each year because of changes to the Earth's centre of mass (Journal of Geophysical Research, Nov 2016). Measuring millimetres must be subject to some scepticism but presumably it involves GPS. The centre of mass is thought to be in the core but what is it they think causes changes – ice and water during winter months. One may wonder if rainfall and snow is all it takes and if it is what on earth would happen if there was a sudden spate of mountain growth – or crustal distortion such as the uplift of the Tibetan Plateau.
