SEISMIC HAZARD PRECURSORY EVOLUTION: FRACTAL AND MULTIFRACTAL ASPECTS

Abstract

One of the important tools for seismic hazard risk assessment is study of the dynamics of properties of spatio-temporal distribution of the seismicity. We have performed simulation of the crack network development in elastic body under external stresses. We show that the crack network evolve from the state with random, chaotic distributions of cracks and seismicity to the state with fractal, clustered patterns. The validity of the results of simulations has been supported by the results of case studies of the seismicity catalogs for Japan and Southern California. It is shown that the variations of several multifractal characteristics (correlation dimension, information dimension, higher order generalized fractal dimensions, the abscissa of the top of multifractal spectrum) contain information about evolution of the system towards main rupture. We have found the certain tendencies in behavior of each multifractal characteristics which are in agreement with the results of simulation.