Is the Nutation of the Solid Inner Core Responsible for the 24-Year Libration of the Pole?

Abstract

Abstract busse’s (1970) theory of the dynamical coupling between the rigid inner core and mantle of the Earth through the pressure reactions in the fluid outer core is examined. It is confirmed that the rigid inner core has the eigenfrequency, (1—ρf/ρr)erΩ0, of nutation (Ω0: the mean rotation rate of the Earth, er: ellipticity of the rigid inner core, and ρf, ρr: the densities of the fluid outer and rigid inner cores, respectively), but it is concluded to be extremely difficult to interpret the 24-yr libration of the pole suggested by markowitz (1960, 1968) in terms of the nutation with this frequency.