====== Earth's core rotation speed ======

In the 1990s, several different research groups independently published details of studies which suggested that the Earth's [[content:earth_sciences:earth_core|solid inner core]] is rotating slightly faster that the rest of the planet. ([[https://ui.adsabs.harvard.edu/abs/1996Natur.382..221S/abstract|example study]] )

Results indicated that the core is rotating about 0.3 to 1 degree per year faster - so called 'Super Rotation'. The theories were developed from analysis of seismic data collected during earthquakes.

New (2023) research suggests that the core //may have slowed down again,// and that the variations  - speeding and slowing -  might be part of a repeating cycle over several decades.

Why the rotation speed varies, and what drives the super-rotation is unknown.

See : [[https://www.nature.com/articles/s41561-022-01112-z|Nature Geoscience]] (2023) 'Multidecadal variation of the Earth’s inner-core rotation'.

Note that it's not known what effects (if any) the speed changes may have on the [[content:earth_sciences:geomagnetic_field]].