Statistical analysis of ensembles of strong motion records

spatial variations of strong motion are generally studied in terms of atten uation laws far peak ground accelerations with reference to the epicentre, located from long distance records, The question arises, how a set of stron g motion records obtained from arbitrarily located stations are inter-relat ed among themselves and with the epicentre, To answer this question, a new approach is proposed in this paper by deter mining a force centre statistic ally from the set of recorded accelerograms.