Head-to-tail plume shrinking contributes to the Hawaiian-Emperor Bend and plume zonation

Abstract The Hawaiian-Emperor Bend (HEB) is traditionally attributed to the motion of the Pacific plate over a fixed or drifting mantle plume. Yet, the role of the plume's evolving radius in this process remains unexplored. We incorporate a shrinking plume head into plate reconstructions to investigate the formation of the HEB. Initially, the plume transported magma near the Kula-Pacific plate boundary, ~1500 km away from the plume axis. During 80-47 Ma, the shrinking plume head compelled newly formed craters to move from the mid-ocean ridge toward the mantle plume axis, forming an age-progressive volcanic chain on the moving plate and with decreased asthenospheric material signatures. After 47 Ma, seamounts approached the plume axis, causing the later island chain to align more parallel to the plate motion and exhibit more distinct plume signatures. Our model thus provides a new mechanism that contributed to the migration and compositional change of the Hawaiian-Emperor seamounts during the plume-plate interaction.