Top, vertical displacement times series for two marsquake signals (brown). S0235b is one of the highest-SNR events observed thus far and shows clear P- and S-wave arrivals. S0105a is an example of a lower-SNR event; for such events P- and S-wave arrivals are determined using power density function envelopes2. Note the different amplitude scales. Bottom, vertical components of two earthquake signals at a similar distance, recorded at the FIESA and DAVOX stations of the Swiss Seismic Network46. The shallow earthquake in Greece has visible surface waves, which are not detectable for either the deep earthquake or the marsquakes. All waveforms were corrected for instrument response and filtered between 0.125 and 0.5 Hz (marsquakes) or 0.033 and 0.5 Hz (earthquakes). For the marsquakes, the instrument noise exceeds the signal at about 0.1 Hz, hence the different filter.