Developments in seismic source theory

The basic stimulus for the development of a quantitative theory of seismic or earthquake sources is simply the desire to achieve some depth of understanding of this complex phenomenon. Beyond this intrinsic desire to unify and understand, a variety of applications of that understanding can be made which have considerable practical importance. In particular, the most important current applications of seismic source theory are to earthquake‐explosion discrimination and to earthquake prediction and control. Indeed, perhaps the greatest stimulus to theoretical work in seismic source theory in recent years has come from the diverse, and sometimes contradictory, observational data obtained in studies related to these particular problems. Thus while a large number of empirical relationships have been defined from the data, it is clear that a general theoretical framework is needed to unify the empirical results and to provide predictions outside the range and resolution of current observations as well as to provide deeper understanding of the meaning of the observations.