This book presents the formulations and solutions of the wave equation for the Earth’s free oscillations concerning the particular nodal, bifurcation, perspectival, and projective reference points within the framework of the three “great geometries” of Euclid, Lobachevsky, and Riemann.

When studying the relationship between the propagation velocity of various types of bulk and surface seismic waves with radial, spheroidal, and torsional eigen oscillations of the Earth having corresponding periods, we are struck by the fundamental problem of obtaining reference points...