Abstract
Satellite imagery reveals flowstripes on Foundation Ice Stream parallel to ice flow, and meandering features on the ice-shelf that cross-cut ice flow and are thought to be formed by water exiting a well-organised subglacial system. Here, ice-penetrating radar data show flow-parallel hard-bed landforms beneath the grounded ice, and channels incised upwards into the ice shelf beneath meandering surface channels. As the ice transitions to flotation, the ice shelf incorporates a corrugation resulting from the landforms. Radar reveals the presence of subglacial water alongside the landforms, indicating a well-organised drainage system in which water exits the ice sheet as a point source, mixes with cavity water and incises upwards into a corrugation peak, accentuating the corrugation downstream. Hard-bedded landforms influence both subglacial hydrology and ice-shelf structure and, as they are known to be widespread on formerly glaciated terrain, their influence on the ice-sheet-shelf transition could be more widespread than thought previously.
Description
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Citation
Jeofry, H., Ross, N., Le Brocq, A., Graham, A., Li, J., Gogineni, P., Morlighem, M., Jordan, T., & Siegert, M. J. (2018). Hard rock landforms generate 130 km ice shelf channels through water focusing in basal corrugations. Nature communications, 9(1), 4576. https://doi.org/10.1038/s41467-018-06679-z