A starting earthquake with harmonic effects

Abstract

The possibility of the occurrence of a starting earthquake with harmonic vibrations (caused by the vertical harmonic effect) of the lithospheric plates and the base on which the plates are resting is considered. This case differs from the static one [1], for which the boundary problem operator is characterized by the presence of manifold eigenvalues. In the dynamic case, the eigenvalues of the operator are single. It is found that the starting earthquake also occurs in this case and, in addition, earthquake hazard can increase due to the appearance of fatigue breakdown conditions in the zone of the approach of lithospheric plates. In turn, fatigue breakdown is related to periodic changes in the effective directions of maximal stresses in this zone.