TY - JOUR T1 - Using surface velocities to calculate ice thickness and bed topography: a case study at Columbia Glacier, Alaska, USA JF - Journal of Glaciology Y1 - 2012 A1 - R  W McNabb A1 - Regine Hock A1 - Shad OʼNeel A1 - L  A Rasmussen A1 - Ahn, Y. A1 - M Braun A1 - H Conway A1 - Herreid, S. A1 - Ian Joughin A1 - W. Tad Pfeffer A1 - B  E Smith A1 - Martin Truffer VL - 58 IS - 212 ER -