Identification criteria for sources of T waves recorded in French polynesia

From a data set of 150 digital records of T phases from 71 sources obtained on seismometers of the Polynesian Seismic Network, we define a discriminan t separating earthquake and explosion sources, which uses the maximum ampli tude of recorded ground velocity, measured on its envelope, e(Max) (in mum/ s), and the duration of the phase measured at 1/3 of maximum amplitude, tau (1/3) (in seconds). Earthquake sources and man-made explosions are effecti vely separated in a log-log space by the straight line.