BLOCK STRUCTURE OF THE GEOPHYSICAL MEDIUM

Abstract

We wish to determine the causes of the spatial and temporal hierarchical properties of the block structure of the geophysical medium. In the present paper we suggest an interpretation of this phenomenon. We know from general physical arguments that solids remain in the consolidated state until their internal energy density becomes greater than the bonding energy. When the energy density of some volume reaches the critical value, the medium will break down into blocks separated by one or more joints. The size of the joint will depend on the rate of accumulation of energy in a local volume, which in turn depends on the relationship between the processes of accumulation of energy and its removal from the system. From this standpoint, the correlation between the rates of tectonic processes and the relaxation properties of the geophysical medium should determine the block sizes in this medium. We discuss the possible factors governing this characteristic. We postulate that the spatial and temporal structure of seismicity observed in the geophysical medium is a manifestation of the general statistical evolution of this open system, which can be used as the basis for a general model of the seismic process.