Global 3D configuration of seismic velocity heterogeneities in the mantle as imaged by seismic tomography
Global 3D configuration of seismic velocity heterogeneities in the mantle as imaged by seismic tomography Global 3D configuration (extending from the mapped surface to the core-mantle boundary) of seismic velocity heterogeneities in the mantle as imaged by seismic tomography. Red regions have relatively low S-wave velocities, while blue regions have relatively fast S-wave velocities. The image is dominated by two enormous low-velocity regions, beneath Africa and the central Pacific plates, and by a ring of high velocities underlying subduction zones around the rim of the Pacific. (Image courtesy of A. Dziewonski).