Mass Balance Studies on McCall Glacier Brooks Range, Alaska

Mass balance results are given for the 1968/69 and 1969/70 hydrological years. The year was arbitrarily divided into 'winter' (1 October to 30 April) and 'summer' (1 May to 30 September). Balances were relatively small: mean winter balances were 152 mm (water equivalent) in 1968/69 and 221 mm in 1969/70, and mean annual balances were -326 mm in 1968/69and -177 mm in 1969/70. Mean annual balances of 'Hanging' Glacier, a smaller glacier adjacent to McCall Glacier and within the same basin, were -168 mm in 1968/69 and 36 mm in 1969/70. Preliminary analysis shows that the mean balance of McCall for the preceding 11 years was -265 mm yr 1. Photographic studies on two other glaciers in the Brooks Range indicate recession for the past 60 years.