Mapping the grounding zone of the Amery Ice Shelf, East Antarctica using InSAR, MODIS and ICESat

• Published in: Antarctic Science
• Main Authors: Fricker, Helen Amanda, Coleman, Richard, Padman, Laurie, Scambos, Ted A., Bohlander, Jennifer, Brunt, Kelly M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2009
• Subjects: East Antarctica; Amery; Amery Ice Shelf; Antarc*; Antarctic Science; Antarctica; Ice Shelf
• Online Access: http://dx.doi.org/10.1017/s095410200999023x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410200999023X

Abstract 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 Amery Ice Shelf (AIS) grounding zone (GZ), including its islands and ice rises. The break-in-slope, as an indirect estimate of grounding line location, was mapped for the entire AIS. We have also mapped ∼55% of the landward 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-derived GZ in two regions. Our map redefines the extent of floating ice in the south-western AIS and identifies several previously unmapped grounded regions, improving our understanding of the stresses supporting the current dynamical state of the ice shelf. Finally, we identify three along-flow channels in the ice shelf basal topography, approximately 10 km apart, 1.5 km wide and 300–500 m deep, near the southern GZ. These channels, which form at the suture zones between ice streams, may represent zones of potential weakness in the ice shelf and may influence sub-ice-shelf ocean circulation.