Fig. 8From: Long-duration seismicity and their relation to Copahue volcano unrestThe broad-band tremor occurred at 09:20:00 UTC on 1 June 2012. a Time evolution of the energy in the range 0.5–10 Hz. b The 1608 1-min PSD composing the episode along with the most probable PSD (pPSD), in orange. c Schematic representation of the measures of dominant frequency \(f_d\), frequency range \(f_{range}\), and energy eBack to article page