01821nas a2200157 4500008004100000245008000041210006900121300001200190490000700202520128600209100001801495700002501513700002201538700001901560856008401579 2013 eng d00aThe propagation of a surge front on Bering Glacier, Alaska, 2001–20110 apropagation of a surge front on Bering Glacier Alaska 2001821120 a221-2280 v543 aBering Glacier, Alaska, USA, has a ∼20 year surge cycle, with its most recent surge reaching the terminus in 2011. To study this most recent activity a time series of ice velocity maps was produced by applying optical feature-tracking methods to Landsat-7 ETM+ imagery spanning 2001–11. The velocity maps show a yearly increase in ice surface velocity associated with the down-glacier movement of a surge front. In 2008/09 the maximum ice surface velocity was 1.5 ± 0.017 km a–1 in the mid-ablation zone, which decreased to 1.2 ± 0.015 km a–1 in 2009/10 in the lower ablation zone, and then increased to nearly 4.4 ± 0.03 km a–1 in summer 2011 when the surge front reached the glacier terminus. The surge front propagated down-glacier as a kinematic wave at an average rate of 4.4 ± 2.0 km a–1 between September 2002 and April 2009, then accelerated to 13.9 ± 2.0 km a–1 as it entered the piedmont lobe between April 2009 and September 2010. The wave seems to have initiated near the confluence of Bering Glacier and Bagley Ice Valley as early as 2001, and the surge was triggered in 2008 further down-glacier in the mid-ablation zone after the wave passed an ice reservoir area.1 aTurrin, James1 aForster, Richard, R.1 aLarsen, Chris, F.1 aSauber, Jeanne uhttp://www.ingentaconnect.com/content/igsoc/agl/2013/00000054/00000063/art00024