Fig. 2
From: On the observation of magnetic events on broad-band seismometers
Examples of 2017/09/07 SSC event recordings at seismic stations located at different latitudes. Data spans 1 h, starting 15 min before the onset of the SSC event. For each site, the upper panel shows in red the horizontal magnetic intensity (H) at the closest magnetic stations of the INTERMAGNET network. Middle panel shows the low-pass filtered (0.01 Hz) seismic acceleration and lowermost panel shows the spectrogram of the filtered seismic signal. Amplitude scale for the seismic signals is in m/s2 × 10 −9