Dynamic surface topography: A new interpretation based upon mantle flow models derived from seismic tomography

Abstract

The very long wavelength (i.e. in the degree range ℓ = 1–8) dynamic topography at the Earth's surface, estimated by isostatic reduction of the observed topography, is shown to be in good agreement with the topography predicted by a model of viscous flow in the mantle. This flow model was previously derived by independent consideration of the observed nonhydrostatic geoid and is based upon a recent model of large‐scale seismic shear velocity heterogeneity in the mantle. Our estimate (and prediction) of the long wavelength dynamic surface topography reveals significant depressions (≈ 2–3 km) of the continental shields relative to their hydrostatic reference positions.