The book provides a description of the theory of earthquakes, starting with the tensorial
force of the seismic moment and including the static deformations, the primary spherical-

shell P and S waves and the seismic main shock. Vibrations of the spherical Earth and

elastic half-space are presented and elements of seismometry and structural engineering

are included. Also, earthquakes produced by explosions, meteorites or involving seas and

oceans are described and the mechanism of earthquakes focus is discussed. The book

introduces the notion of elementary earthquakes.

The presentation is made by using the theory of elasticity for isotropic elastic solids,

elements of the physics of fluids and equations of mathematical physics. Special attention

is given to the effect of the boundaries and inhomogeneities.