Superplumes from the core-mantle boundary to the lithosphere: implications for heat flux.
Three-dimensional modeling of upper-mantle anelastic structure reveals that thermal upwellings associated with the two superplumes, imaged by seismic elastic tomography at the base of the mantle, persist through the upper-mantle transition zone and are deflected horizontally beneath the lithosphere. This explains the unique transverse shear wave isotropy in the central Pacific. We infer that the two superplumes may play a major and stable role in supplying heat and horizontal flow to the low-viscosity asthenospheric channel, lubricating plate motions and feeding hot spots. We suggest that more heat may be carried through the core-mantle boundary than is accounted for by hot spot fluxes alone.
Romanowicz
Barbara
B
Seismological Laboratory, University of California, Berkeley, 215 McCone Hall, Berkeley, CA 94720, USA. barbara@seismo.berkeley.edu
Gung
Yuancheng
Y