Crary Ice Rise Research Articles

Numerical Modeling of Ice-Shelf Motion

Finite-element simulations of the Ross Ice Shelf flow yield good qualitative agreement with observation, but velocity magnitudes tend to be too low up-stream of ice rises and too high near the ice front. These errors will be significantly reduced by better model convergence to the flow law, more accurate values of the flow-law parameters, better resolution of the ice streams, and inclusion of subgrid scale stress variability produced by crevassing and ice-fabric orientation. A model run featuring a hypothetical ice rise down-stream of Crary Ice Rise indicates that the distinctive strain-rate patterns produced by an isolated ice rise can be cancelled by neighboring ice rises. This suggests that an isolated ice rise might migrate up-stream along sea-bed ridges unless there are neighboring ice rises acting to stabilize the surrounding ice-thickness tendencies.

Field Studies of Bottom Crevasses in the Ross Ice Shelf, Antarctica (Abstract only)

Surface and airborne radar sounding data were used to identify and map fields of bottom crevasses on the Ross Ice Shelf. Two major concentrations of crevasses were found, one along the grid-eastern grounding line and another, made up of eight smaller sites, grid-west of Crary Ice Rise.Based upon an analysis of bottom crevasse heights and locations, and of the strength of radar waves diffracted from the apex and bottom corners of the gridcrevasses, we conclude that the crevasses are formed at discrete locations on the ice shelf. By comparing the locations of crevasse formation with ice thickness and bottom topography, we conclude that most of the crevasse sites are associated with grounding. Hence we have postulated that six grounded areas, in addition to Crary Ice Rise and Roosevelt Island, exist in the grid-western sector of the ice shelf. These pinning points may be important for interpreting the dynamics of the West Antarctic ice sheet.

Numerical Modeling of Ice-Shelf Motion

Finite-element simulations of the Ross Ice Shelf flow yield good qualitative agreement with observation, but velocity magnitudes tend to be too low up-stream of ice rises and too high near the ice front. These errors will be significantly reduced by better model convergence to the flow law, more accurate values of the flow-law parameters, better resolution of the ice streams, and inclusion of subgrid scale stress variability produced by crevassing and ice-fabric orientation. A model run featuring a hypothetical ice rise down-stream of Crary Ice Rise indicates that the distinctive strain-rate patterns produced by an isolated ice rise can be cancelled by neighboring ice rises. This suggests that an isolated ice rise might migrate up-stream along sea-bed ridges unless there are neighboring ice rises acting to stabilize the surrounding ice-thickness tendencies.