Assessment of the seismology techniques used in previous studies (see Section 5.1). (a) Scatter plot between log⟨ρ⟩ and log v_amp. The dashed red line indicates their theoretical relation with a slope of −1/4 based on Equation (16). (b) Derivative dlog v_amp/dlog⟨ρ⟩ as a function of height (z). The theoretical value (−1/4) based on Equation (16) is also depicted with the dashed red line. We note that in panel a, the height decreases from left to right.