Fig. 4: Attenuation at seismic and Phobos’s tide periods deduced from the 100 best models.
From: Geophysical evidence for an enriched molten silicate layer above Mars’s core
a,b, Present-day shear attenuation profiles at 1 Hz for the inversion set without a BML (a) and with a BML (b) for various frequency dependence (αq) of the shear quality factor. c, Apparent shear quality factor for the S-reflected wave, QScS, at 1 Hz and for event S1222a as a function of the global quality factor at Phobos tidal frequency (5 h 55 min). QScS was computed by integrating 1/Qμ for each model along the ScS raypath, determined using the TauP toolkit60. Models without BML are displayed in green tones and models with a BML are as shown in purple tones depending on the value of αq. The acceptable ranges for QScS and Qμ are displayed in pink. d, QScS at 1 Hz and for event S1222a as a function of \({R}_{Q}^{* }\), the ratio of reflected S to direct S amplitudes AScS/AS between events S0185a and S1222a at 1 Hz that samples different solid mantle depths. The colour and symbol coding are identical to that in c.
