Fig. 5: The curvature of flexure and T_e along the HESC based on Model D.

a The curvatures (maximum positive, maximum negative) of flexure due to individual seamount and ocean island loads. The vertical green bar shows, for comparison, the maximum positive curvatures at the CPTOR²¹. b Age of the Pacific oceanic plate at the time of loading. c Comparison of the observed T_e (colored according to RMS difference between the observed and calculated gravity) to the’yield T_e’ (black solid line) derived from a Yield Strength Envelope (YSE) based on the brittle¹⁶ and ductile flow^17,18 laws and the observed maximum positive (black line) and maximum negative curvature (purple line). Thin red dotted lines show the depth to the 300, 450, and 600 °C oceanic isotherms based on a cooling plate model⁴⁰. Green-filled lines show the depth to the controlling isotherms that best fit T_e in the weak zone (340–350 ^oC, upper curve) and in the strong zone (671–714 ^oC, lower curve) of the CPTOR²¹.