Some characteristics of seismic activity

Abstract

The final objective of any investigation into the seismicity of a region is to find symptoms of an approaching shock, its location, magnitude and time of origin. So far, only average numbers on seismic risk can be estimated because there is no complete physical understanding of focal processes, therefore seismologists combine different empirical relations, simple statistical models or some regularities in the spatial distribution of foci for solving some partial tasks. Among the most frequently used characteristics are the magnitude-frequency (or energy-frequency) relation with its parameters (slope, M _max, M _min), strain (or energy) release with time and space and fault plane solutions. Statistical methods are frequently applied because they can supply us with numerical characteristics of seismic activity, e. g. the earthquake phenomena are correlated between different regions or with other geophysical parameters (Earth tides), the sequences of shocks are analyzed using the theory of time series, the theory of largest values, Poisson or other distributions, etc.