Figure 5. Percentage of shear (top left panel) and compressional wave velocity perturbations (bottom left panel) required to explain the observed differential travel time residuals in a 220 km thick layer above the CMB. Averaged shear (top right panel) and compressional wave velocity perturbations (bottom right panel) in the bottom 220 km of the mantle are inferred from the corrected travel time residuals. (From Rao and Ravi Kumar, 2022b) (Reprinted from Journal of Asian Earth Sciences, 225, Padma Rao B., Ravi Kumar M., Lowermost mantle (D” layer) structure beneath the Indian Ocean: Insights from modeling of ScS-S and PcP-P residuals, 105038, Copyright (2022), with permission from Elsevier.)