We characterize the basal mass balance of the Ekstr ¨om Ice
Shelf, Dronning Maud Land, Antarctica, using interferometrically
derived surface velocities and ice thickness measurements from
radio-echo sounding (RES). The surface velocities are based on
data from European Remote-sensing Satellites-1 and -2 (ERS-1/2)
during 1994–97. The ice thickness grid consists of 136 RES
profiles acquired between 1996 and 2006. Mass fluxes are
calculated along selected RES profiles where possible, to reduce
uncertainties from ice thickness interpolation. Elsewhere large-
scale mass fluxes are calculated using interpolated ice
thickness data. Themass flux into the Ekstr ¨om Ice Shelf from
themain grounded drainage basins is estimated to be 3.19±0.4Gt
a−1. The mass flux near the ice shelf front is 2.67±0.3Gt a−1.
Assuming steady state, and based on the equation of continuity,
we interpret the residual mass flux as a combined effect of snow
accumulation and subglacial melting/refreezing. Using net snow
accumulation rates from pre