Hard rock landforms generate 130 km ice shelf channels through water focusing in basal corrugations

• Published in: Nature Communications
• Main Authors: Jeofry, Hafeez, Ross, Neil, Le Brocq, Anne, Graham, Alastair G.C., Li, Jilu, Gogineni, Prasad, Morlighem, Mathieu, Jordan, Thomas, Siegert, Martin J.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Research 2020
• Subjects: Foundation Ice Stream; Ice Sheet; Ice Shelf
• Online Access: http://hdl.handle.net/1808/30944; https://doi.org/10.1038/s41467-018-06679-z

This work is licensed under a Creative Commons Attribution 4.0 International License. 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. NASA grant # NNX10AT68G ANT # NT-0424589 University of Kansas UK NERC AFI grant NE/G013071/1