2 November 2020
Observed since the end of the 19th century, the displacement of the pole of rotation with respect to the Earth’s crust (of the order of ten meters on the scale of one year) is a reflection of the properties of the Earth and of various geophysical processes, ranging from mass transport atmospheric to global climate change.
After recalling the lineaments of its observation, the author deepens the traditional theoretical description of the polar motion in the light of the rheological properties of the Earth, then discusses how hydro-atmospheric mass transport sustains it over time scales ranging from half a day to a few decades.
The last chapter is devoted to the drift of the pole in geological periods, which proceeds from cycles of glaciation or tectonic motion for a visco-elastic mantle.