Combined geodetic, geophysical and glaciological in situ measurements are interpreted regarding surface height changes over subglacial Lake Vostok and the local mass balance of the ice sheet at Vostok station. Repeated GPS observations spanning 5 years and long-term surface accumulation data show that the height of the lake surface has not changed over the observation period. The application of the mass conservation equation to purely observational data yields an ice mass balance for Vostok station close to equilibrium.

Supplement to: Richter, Andreas; Popov, Sergey V; Dietrich, Reinhard; Lukin, Valeriy V; Fritsche, Mathias; Lipenkov, Vladimir Ya; Matveev, Alexey Y; Wendt, Jenny; Yuskevich, A V; Masolov, Valery N (2008): Observational evidence on the stability of the hydro-glaciological regime of subglacial Lake Vostok. Geophysical Research Letters, 35(11)