Fig. 4: Seismic velocity profiles from the inversion.

a The three-layer crustal models beneath the InSight landing site from the receiver function study¹¹, with an intra-crustal interface at 20 ± 5 km. The color scale indicates the number of models. b Inverted S-wave speed models at the bounce point with two layers in the upper crust from the SS precursors in this study. c Similar to (b), but with one layer in the upper crust. d Similar to (c), but for the P-wave speed with one layer in the upper crust. e Normalized probability density functions for the depth of the intra-crustal interfaces beneath the landing site (in shaded red) from the receiver function study¹¹, and at the bounce point from the precursor constraints (in solid and dashed curves). The inferred interface depth at the landing site from another study¹³ is also shown as a horizontal bar. f Normalized probability density functions for the S-wave speed in the second layer beneath the lander (in shaded red), in the second layer for models in (b), and the first layer for models in (c) at the bounce point. g Similar to (f), but for the P-wave speed.