Astronomical frequencies for pre-Quaternary palaeoclimate studies

The sensitivity of the Earth's orbital frequencies, involved in the astronomical theory of palaeoclimates, to the Earth-Moon distance and consequently to the length of the day and to the dynamical ellipticity of the Earth has been investigated for the last billion years. The shortening of the Earth-Moon distance and of the length of the day back in time induces a shortening of the fundamental astronomical periods for the obliquity and the precession, a shortening which is larger for the longer periods. These periods of precession and obliquity influenced by the changing Earth-Moon distance, length of the day and dynamical ellipticity of the Earth, have been recomputed for the last 440 million years.