A Study of the Tidal Modulation of Ice-shelf Flow using a Viscoelastic Model of the Ross Ice Shelf

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This award supports a two-year study of the flow of the Ross Ice Shelf, Antarctica, which is the portion of the Antarctic ice sheet that is floating on the Ross Sea. The Ross Ice Shelf (along with the Filchner-Ronne Ice Shelf) provides an important, stabilizing back-pressure on the seaward flow of the West Antarctic Ice Sheet, which is the portion of the Antarctic ice sheet that is most at risk of catastrophic disintegration. The study aims to understand the interaction between the Ross Ice Shelf and the ocean by developing a map-plane two-dimensional, viscoelastic, ice-flow model. This model will explore the tidal modulation of mean, time-averaged ice-shelf flow velocity. The model will then be assessed based on GPS measurements that have previously been collected in the field, at a site near the center of the seaward, iceberg-calving front of the ice shelf. The results of this ice-dynamics study will contribute significantly to the ice-sheet modeling community by: 1) providing an independent assessment of both the viscous and elastic components of the ice-shelf response to the ocean tide; 2) providing a better understanding of the sensitivities of the coupled ocean/ice-shelf system; and 3) incorporating both viscous and elastic elements into an integrated ocean/ice-shelf/ice-stream system that addresses tidal modulation of the flow of glacial ice across the grounding line. Having an increased understanding of the ice-shelf-flow dynamics, and an understanding of the teleconnection between the ice shelves and the ice sheets via the ice streams, will assist ice-sheet modelers to better understand the evolution of the West Antarctic Ice Sheet, which is currently the largest Antarctic contribution to mean-sea-level rise.