Fig. 1

Seismograms during the 2017/09/07 SSC event. Seismograms show 1 h of the vertical seismic acceleration, as recorded by the 82 broad-band stations distributed worldwide with positive identifications. The traces are normalized in amplitude after low-pass filtering at 0.01 Hz and ordered by latitude (labels show reference latitudes). The upper left panel map shows with red dots the sites with clear seismic recording of the SSC event and with black dots, the stations without clear evidences. Upper right panel shows the peak amplitude of the seismic signals as a function of latitude