Mapping the grounding zone of the Amery Ice Shelf

• Published in: Antarctic Science
• Main Authors: Fricker, HA, Coleman, R, Padman, L, Scambos, TA, Bohlander, J, Brunt, KM
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge Univ Press 2009
• Subjects: Earth Sciences; Physical Geography and Environmental Geoscience; Glaciology; Amery; Amery Ice Shelf; Antarctic Science; Ice Shelf
• Online Access: https://doi.org/10.1017/S095410200999023X; http://ecite.utas.edu.au/62105

We use a combination of satellite techniques (interferometric synthetic aperture radar (InSAR),visible-band imagery, and repeat-track laser altimetry) to develop a benchmark map for the AmeryIce Shelf (AIS) grounding zone (GZ), including its islands and ice rises. The break-in-slope, as an indirectestimate of grounding line location, was mapped for the entire AIS. We have also mapped ,55% of thelandward edge and ,30% of the seaward edge of the ice shelf flexure boundary for the AIS perimeter.Vertical ice motion from Global Positioning System receivers confirms the location of the satellite-derivedGZ in two regions. Our map redefines the extent of floating ice in the south-western AIS and identifiesseveral previously unmapped grounded regions, improving our understanding of the stresses supporting thecurrent dynamical state of the ice shelf. Finally, we identify three along-flow channels in the ice shelf basaltopography, approximately 10 km apart, 1.5 km wide and 300500m deep, near the southern GZ. Thesechannels, which form at the suture zones between ice streams, may represent zones of potential weakness inthe ice shelf and may influence sub-ice-shelf ocean circulation.