Antarctic Science

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Antarctic Science (2009), 21:515-532 Cambridge University Press
Copyright © Antarctic Science Ltd 2009
doi:10.1017/S095410200999023X

Physical Sciences

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


Helen Amanda Frickera1 c1, Richard Colemana2a3a4, Laurie Padmana5, Ted A. Scambosa6, Jennifer Bohlandera6 and Kelly M. Brunta1

a1 Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0225, USA
a2 Centre for Marine Science, University of Tasmania, Private Bag 115, Hobart, TAS 7001, Australia
a3 Antarctic Climate and Ecosystems CRC, Hobart, Australia
a4 CSIRO Marine and Atmospheric Research, Hobart, Australia
a5 Earth & Space Research, 3350 SW Cascade Ave, Corvallis, OR 97333-1536, USA
a6 National Snow and Ice Data Center, CIRES, Campus Box 449, 1540 30th St, University of Colorado, Boulder, CO 80309-0449, USA
Article author query
fricker ha [PubMed]  [Google Scholar]
coleman r [PubMed]  [Google Scholar]
padman l [PubMed]  [Google Scholar]
scambos ta [PubMed]  [Google Scholar]
bohlander j [PubMed]  [Google Scholar]
brunt km [PubMed]  [Google Scholar]

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 xs223C55% of the landward edge and xs223C30% 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.

(Received November 03 2008)

(Accepted April 27 2009)

Key wordsgrounding lines; ice shelves; remote sensing; tides

Correspondence:

c1 hafricker@ucsd.edu


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