The Influence of the Solid Earth on the Contribution of Marine Sections of the Antarctic Ice Sheet to Future Sea-Level Change

Seismic tomography models indicate highly variable Earth structure beneath Antarctica with anomalously low shallow mantle viscosities below West Antarctica. An improved projection of the contribution of the Antarctic Ice Sheet to sea-level change requires consideration of this complexity to precisely account for water expelled into the ocean from uplifting marine sectors. Here we build a high-resolution 3-D viscoelastic structure model based on recent inferences of seismic velocity heterogeneity below the continent. The model serves as input to a global-scale sea-level model that we use to investigate the influence of solid Earth deformation in Antarctica on future global mean sea-level (GMSL) rise. Our calculations are based on a suite of ice mass projections generated with a range of climate forcings and suggest that water expulsion from the rebounding marine basins contributes 4%-16% and 7%-14% to the projected GMSL change at 2100 and 2500, respectively.

Automated summary

Seismic tomography models reveal highly variable Earth structure beneath Antarctica, particularly anomalously low shallow mantle viscosities below West Antarctica. A high-resolution 3-D viscoelastic structure model is built based on seismic velocity heterogeneity inferences, and is combined with a global-scale sea-level model to investigate the influence of solid Earth deformation in Antarctica on future global mean sea-level rise.