Fig. 3.From: Barometric and magnetic observations of vertical acoustic resonance and resultant generation of field-aligned current associated with earthquakesPower spectral density of the barometric data obtained at Mizusawa before (black line) and after the origin time. A clear spectral peak at 260 s appears for one or two hours after the origin time (green and red lines), which indicates the excitation of vertical acoustic resonance caused by the earthquake.Back to article page