Fig. 7
From: Ultra-low velocity zone heterogeneities at the core–mantle boundary from diffracted PKKPab waves
P-wave velocity variations plotted at the middle points of diffracted paths of PKKPab in two regions (marked by box 1 and 2) at the CMB. Slow and fast are shown using black crosses and gray circles, respectively. The background is the P-wave tomographic model at the CMB from GyPSuM (Simmons et al. 2010). The gray stars denote the earthquakes, and the gray inverted triangles denote the stations