A STUDY OF TWO SHORT-PERIOD DISCRIMINANTS

Abstract : The paper is the result of a large-population study of discrimination between earthquakes and explosions, using only short-period data from a single station. The data was obtained from the Large Aperture Seismic Array and the two discriminants studied were waveform complexity and spectral ratio. Procedures for multivariate discrimination are developed and results are given in terms of earthquake identification percentages using these discriminants singly, and in combination with each other and with magnitude. The results are quite encouraging, complete separation being found for explosions and shallow earthquakes using spectral ratio and magnitude together.