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

• Published in: Nature Communications
• Main Authors: Jeofry, H, Ross, N, Le Brocq, A, Graham, A, Li, J, Gogineni, P, Morlighem, M, Jordan, T, Siegert, MJ
• Other Authors: Natural Environment Research Council (NERC), British Council (UK)
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Publishing Group 2018
• Subjects: Science & Technology; Multidisciplinary Sciences; Science & Technology - Other Topics; WEDDELL SEA SECTOR; WEST ANTARCTICA; SUBGLACIAL BEDFORMS; STREAMLINED HARD; GROUNDING LINE; SHEET; BED; BENEATH; MODEL; ZONE; MD Multidisciplinary; Weddell Sea; West Antarctica; Weddell; Foundation Ice Stream; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: http://hdl.handle.net/10044/1/64959; https://doi.org/10.1038/s41467-018-06679-z

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.