A 14 year mass-balance record of a blue-ice area in Antarctica

Accumulation and ablation rates over an Antarctic blue-ice area spanning the 14 year period 1988-2002 are presented. Data were obtained by direct stake measurements. Large spatial and temporal variations in the net balance were observed without any clear trend over the entire period. There are marginally significant increases in snow accumulation, and in ablation in the blue-ice area farthest from the equilibrium zone (both at the 95% confidence level). The snow/blue-ice transition zone shows no change over the entire period of observation, and the blue-ice area near the zone shows no change in ablation rate over the 14 year period. The mass-balance gradient in Scharffenbergbotnen may have increased during the period 1988-2002. However, the changes are small, especially when compared with the changes observed elsewhere in Antarctica even relatively close to the blue-ice area. This may indicate that the blue-ice areas are relatively stable to changes in accumulation rate, and possibly temperature.