The inner core of the Earth is rotating at about 0.05-0.1 degrees per year, according to an analysis of seismic data from repeating earthquakes published in the journal Earth and Planetary Science Letters. Yang & Song found that refracted waves (blue), rather than reflected waves (purple) change over time, providing the best evidence yet that Earth’s inner core is rotating. Image credit: Michael Vincent. Geoscientists do not fully understand...
