Robust Seismic Images of the Hawaiian Plume

To image the Hawaiian plume and the plume-lithosphere interaction, we determine a robust 3-D shear-wave velocity (Vs) model of the upper mantle and the mantle transition zone (MTZ) beneath Hawaii by jointly inverting teleseismic S-wave arrival times, Rayleigh-wave phase velocities, and S-wave receiver functions. The new Vs model reveals a continuous oblate cylinder-like low-Vs zone in the upper mantle beneath the Hawaiian island chain, which is surrounded by visible high-Vs anomalies. The low-Vs zone gradually changes to a column-like zone beneath similar to 400 km depth where the MTZ is thinner. These results not only well illustrate the Hawaiian plume in the upper mantle and the MTZ, but also reflect interaction processes between the Hawaiian plume and the overriding Pacific lithosphere, including lithosphere entraining plume, plume rejuvenating lithosphere, and lithosphere re-aging. Although these processes have been suggested by previous numerical simulations, they are realistically revealed by the present seismic imaging.