FACTOR ANALYSIS IN SEISMOLOGY

Factor analysis allows us to explore the structure of the relationship of variables, where each group of variables will be determined by the factor according to which these variables have maximum loads. The result of factor analysis is a transition from a set of input parameters to a smaller number of variables, called factors. The factor is interpreted as a hidden variable - the cause of joint variability (interrelation) of several initial parameters. A method for calculating of the attenuation function values is proposed. On the basis of the obtained values, the seismic hazard is calculated as the probability that for a fixed time t at points of the earth's surface Q(φ, ψ) n seismic shocks occur, of which m will have intensity Ik of the MSK-64 scale. The method is used to study the seismicity of the Foci Vrancea and earthquakes of Romania. Seismic processes are complex and diverse, since their formation is due to complex, diverse geological and geophysical processes occurring in the bowels of the Earth, and is characterized by many different parameters, and the results of observations on them are represented as multidimensional random variables. In the study of such multiparameter processes, the question arises: is it possible to discard some of the parameters, or replace them with a smaller number of some functions of them, while retaining all the information? To solve this problem is a factor analysis [Bakhtin, at al., 2007]. Factor analysis is based on determining the minimum number of factors that make up the largest share in the variance of the data [Harman, 1972]. In the study of the complex nature of seismicity, factor analysis helps to better understand the essence of seismic processes, since the interdependence between seismic parameters must be due to relationships between parameters, the identification of which is the task of factor analysis.