The free oscillations of a rotating Earth model

 

Dr. Yves Rogister

 

Summary

The spectrum of the elastic-gravitational free oscillations of a rotating Earth model can be divided into three sets: the seismic normal modes, the inertia-gravity spectrum of the liquid outer core,  and the rotational modes, which include the Free Core Nutation, Free Inner Core Nutation, Chandler Wobble, and Inner Core Wobble. The frequencies of the rotational modes are imbedded into the continuous spectrum of liquid outer core, which is governed by both the squared Brunt-Vaisala frequency and the Earth's rotation speed. I will describe the spectrum of a rotating Earth model and show how the dynamics and structure of the outer core may influence the rotational modes.