The −4% (dark red), −2% (red) and 2% (blue) isosurfaces of δlnVS are rendered from EARA2014 (ref. 24). Green lines mark the four suture zones IYS, BNS, JS, and AKMS. For reference, four planes showing variations of δlnVS are cut at depths of 410 and 660 km, and along longitudes 83°E and 92°E. (a) The geometry of Indian (blue) and Asian (blue) lithospheres and the distribution of possible partial melt (dark red) are viewed upward from the south, (b) downward from the south and (c) from the east.