Three New Fundamental Problems in Physics of the Aftershocks

Recently, the physics of aftershocks has been enriched by three new problems. We will conditionally call them dynamic, inverse, and morphological problems. Dynamic problem is to search for the cumulative effect of a round-the-world seismic echo appearing after the main shock of earthquake. According to the theory, a converging surface seismic wave excited by the main shock returns to the epicenter about 3 hours after the main shock and stimulates the excitation of a strong aftershock. The second problem is an adequate description of the averaged evolution of the aftershock flow. We introduced a new concept about the coefficient of deactivation of the earthquake source, and proposed an equation that describes the evolution of aftershocks. Based on the equation of evolution, we posed and solved the inverse problem of the physics of the earthquake source. The third task is to model the spatio-temporal distribution of aftershocks. Its solution refines our understanding of the structure of the earthquake source.