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Abstract:
This chapter describes the large-scale mantle flow structures beneath Antarctica as derived from
global seismic tomography models of the present-day state. In combination with plate reconstruc11 tions, the time-dependent pattern of paleosubduction can be simulated and is also shown from
the rarely seen Antarctic perspective. Furthermore, a dynamic topography model demonstrates
which kind and scales of surface manifestations can be expected as a direct and observable result
of mantle convection. The last section of the chapter features an overview of the classical concept
of deep-mantle plumes from a geodynamic point of view and how recent insights, mostly from
seismic tomography, have changed the understanding of plume structures and dynamics over the
past decades. The long-standing and controversial hypothesis of a mantle plume beneath West
Antarctica is summarised and addressed with geodynamic models, which estimate the excess heat flow of a potential plume at the bedrock surface. However, the predicted heatflow is small while
differences in surface heat flux estimates are large, therefore the results are not conclusive with
regard to the existence of a West Antarctic mantle plume. Finally, it is shown that global mantle
flow would cause tilting of whole-mantle plume conduits beneath West Antarctica such that their
base is predicted to be displaced about 20◦
northward relative to the surface position, closer to
the southern margin of the Pacific Large Low Shear Velocity Provinc
