Fig. 3: Molten silicate layer  and core seismic signatures.

a, Ray paths for LSL- and core-interacting phases: P wave and S wave reflected from the top of the LSL (grey layer) (PdP and SdS), P wave diffracted around the mantle–LSL interface (\({{\rm{P}}}_{{\rm{diff}}}^{{\rm{LSL}}}\)), P wave reflected from the liquid core (PDcDP), P wave diffracted around the LSL–liquid core interface (\({{\rm{P}}}_{{\rm{diff}}}^{{\rm{CMB}}}\)) and reverberating in the LSL (\({{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}}^{\hat{}}{\rm{L}}{\rm{S}}{\rm{L}}\,{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}\)), and liquid-layer and core-transiting P wave (SDKDS). b, Vertical-component synthetic waveform section showing the diffracted P wavetrain for epicentral distances similar to S1000a (126°, see Supplementary Fig. 7 for a larger section). c, Vertical-component observed polarized waveforms (filtered between 0.2–0.7 Hz) and envelopes showing the P_diff arrivals, marked by red, blue and black lines, respectively. The vertical-component template trace employed for waveform matching (e) is shown in magenta and consists of a 10-s-long window including the observed \({{\rm{P}}}_{{\rm{diff}}}^{{\rm{CMB}}}\) arrival. Red- and grey-shaded rectangles represent the travel time predictions for \({{\rm{P}}}_{{\rm{diff}}}^{{\rm{LSL}}}\) and \({{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}}^{\hat{}}{\rm{L}}{\rm{S}}{\rm{L}}\,{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}\), respectively, based on the inverted models shown in Fig. 2, and the yellow-shaded rectangle spans the range satisfying the observed differential travel time (−113 ± 5 s) of \({{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}}^{\hat{}}{\rm{L}}{\rm{S}}{\rm{L}}\,{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}\) relative to PP. d, Three-component scalogram illustrating the temporal change in frequency content. \({{\rm{P}}}_{{\rm{diff}}}^{{\rm{LSL}}}\), \({{\rm{P}}}_{{\rm{diff}}}^{{\rm{CMB}}}\) and \({{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}}^{\hat{}}{\rm{L}}{\rm{S}}{\rm{L}}{{\rm{P}}}_{{\rm{d}}{\rm{i}}{\rm{f}}{\rm{f}}}\) arrivals are indicated by arrows following the colour scheme in c. e, Similarity between event trace and template trace. The horizontal line designates the threshold employed for the waveform matching detections. Coloured arrows as in d. f, Polarization attributes for the three-component seismic data, showing the temporal change in azimuth between 0.2–0.7 Hz. The azimuth across the observed diffracted P wavetrain is consistent with the imaged meteorite impact location of 34° (horizontal cyan line)³³. Supporting seismic waveform processing information is provided in Supplementary Information section 6. S0173a, S1000a and S1094b: locations of a marsquake and two imaged meteorite impacts (Extended Data Table 1).