Figure F24. Tracking RMS (root-mean square) energy levels in one-octave bands is a convenient way to observe time-dependent effects in the broadband seismic data from the Hawaii-2 Observatory. The spikes around 5 and 20 hr in this figure correspond to T-phases from earthquake events. The intense activity between 10 and 15 hr can be associated with the drawworks. RMS level is given in decibels relative to a count.

Figure F24. Tracking RMS (root-mean square) energy levels in one-octave bands is a convenient way to observe time-dependent effects in the broadband seismic data from the Hawaii-2 Observatory. The spikes around 5 and 20 hr in this figure correspond to T-phases from earthquake events. The intense activity between 10 and 15 hr can be associated with the drawworks. RMS level is given in decibels relative to a count.