Tomographic imaging of multiple mantle plumes in the uppermost lower mantle

Abstract

A high-resolution global tomographic inversion of P-wave traveltimes has been under-taken utilizing an a priori model. The results image cylindrical slow velocities in the upper and lower mantle beneath many current hotspot locations. Locations at which such plume-like features are imaged passing from the uppermost lower mantle to the upper mantle include, Afar, Society Islands, Crozet, Kerguelen, Iceland, Hawaii, East Africa, Cape Verde and the Canary Islands. The validity of these images has been investigated with synthetic recovery tests. These images suggest that these plumes could be from the lower mantle and therefore are not hindered in crossing the upper/lower mantle boundary.