The Cryosphere Discuss., 6, 1181-1204, 2012
www.the-cryosphere-discuss.net/6/1181/2012/
doi:10.5194/tcd-6-1181-2012
© Author(s) 2012. This work is distributed
under the Creative Commons Attribution 3.0 License.
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This discussion paper has been under review for the journal The Cryosphere (TC). Please refer to the corresponding final paper in TC.
Surge dynamics on Bering Glacier, Alaska, in 2008–2011
E. W. Burgess1, R. R. Forster1, C. F. Larsen2, and M. Braun3
1Department of Geography, University of Utah, Salt Lake City, Utah, USA
2Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska, USA
3Department of Geography, Friedrich-Alexander-University Erlangen-Nürnberg, Germany

Abstract. A 2008–2011 surge of Bering Glacier, Alaska is examined using observations of surface velocity and surface elevation change. Velocity measurements are obtained using synthetic aperture radar (SAR) offset tracking and elevation data are obtained from the University of Alaska Fairbanks LiDAR altimetry program. Bering Glacier began to surge in May 2008 and had two phases of accelerated flow. The first phase accelerated progressively for at least 10 months and reached peak observed velocities of ~7 m d−1. Results suggest that during the quiescent phase, prior to the surge, periods of accelerated flow increased driving stresses up to 70% in a ~10 km-long section of the Lower Bering. When the first phase of the surge initiated, synchronous acceleration occurred throughout much of the glacier length, indicating widespread pressurization of the bed, but the largest accelerations initiated at the location where driving stress built up during quiescence. From there, rapid flow velocities propagated upstream and downstream across much of the glacier length and transpired as small, transient and unorganized propagation fronts. The second phase occurred in 2011 and was of comparable scale to the surge in 1993–1995, with velocities exceeding 9 m d−1 or ~18 times quiescent velocities.

Citation: Burgess, E. W., Forster, R. R., Larsen, C. F., and Braun, M.: Surge dynamics on Bering Glacier, Alaska, in 2008–2011, The Cryosphere Discuss., 6, 1181-1204, doi:10.5194/tcd-6-1181-2012, 2012.
 
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