Ice Flow Direction Change in Interior West Antarctica
Martin J. Siegert,1*
Brian Welch,2
David Morse,3
Andreas Vieli,1
Donald D. Blankenship,3
Ian Joughin,4
Edward C. King,5
Gwendolyn J.-M. C. Leysinger Vieli,1
Antony J. Payne,1
Robert Jacobel2
Upstream of Byrd Station (West Antarctica), ice-penetrating
radar data reveal a distinctive fold structure within the ice,
in which isochronous layers are unusually deep. The fold has
an axis more than 50 kilometers long, which is aligned up to
45° to the ice flow direction. Although explanations for
the fold's formation under the present flow are problematic,
it can be explained if flow was parallel to the fold axis
1500
years ago. This flow change may be associated with ice stream
alterations nearer the margin. If this is true, central West
Antarctica may respond to future alterations more than previously
thought.
2 Physics Department, St. Olaf College, Northfield, MN 55057, USA.
3 Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, The University of Texas, 4412 Spicewood Springs Road, Austin, TX 78759, USA.
4 Jet Propulsion Laboratory, Mail Stop 300-235, 4800 Oak Grove Drive, Pasadena, CA 91109, USA.
5 Physical Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK.
* To whom correspondence should be addressed. E-mail: m.j.siegert{at}bristol.ac.uk
