Fig. 4
From: Ultrahigh-pressure acoustic wave velocities of SiO2-Al2O3 glasses up to 200 GPa
P-V S profiles up to 200 GPa. SA1 (blue squares, this study), SA2 (light blue diamonds, this study), SiO2 glass (red circles, Murakami and Bass 2010), and MgSiO3 glass (green triangles, Murakami and Bass 2011). The curves show the fourth order polynomial fitting of SA1 (R 2 = 0.9960), SA2 (R 2 = 0.9978), SiO2 glass (R 2 = 0.9964), and MgSiO3 glass (R 2 = 0.9985). The pressure conditions at which the increase of dV S /dP occurs (the inflection pressure) are indicated by the semi-transparent dark-blue box (SA1) and the semi-transparent light-blue box (SA2)