Spatial and temporal variability in isotope composition of recent snow in the vicinity of Vostok station, Antarctica: implications for ice-core record interpretation

Continuous, detailed isotope (deltaD and delta(18)O) profiles were obtained from eight snow pits dug in the vicinity of Vostok station, Antarctica, during the period 1984-2000. In addition, snow samples taken along the 1 km long accumulation-stake profile were measured to determine spatial variability in isotope composition of recent snow. The stacked deltaD time series spanning the last 55 years shows only weak correlation with the mean annual air temperature recorded at Vostok station. Significant oscillations of both snow accumulation and snow isotope composition with the periods 2.5, 5, 20 and, possibly, similar to10(2) years observed at single points are interpreted in terms of drift of snow-accumulation waves of various scales on the surface of the ice sheet.