%0 Journal Article %J Journal of Glaciology %D 2012 %T Using surface velocities to calculate ice thickness and bed topography: a case study at Columbia Glacier, Alaska, USA %A R  W McNabb %A Regine Hock %A Shad OʼNeel %A L  A Rasmussen %A Ahn, Y. %A M Braun %A H Conway %A Herreid, S. %A Ian Joughin %A W. Tad Pfeffer %A B  E Smith %A Martin Truffer %B Journal of Glaciology %V 58 %P 1151-1164 %G eng %N 212 %R 10.3189/2012JoG11J249