Mass-balance studies on Siachen Glacier in the Nubra valley, Karakoram Himalaya, India

Abstract

Abstract The hydrological method is used to compute the mass balance of Siachen Glacier in the Nubra Valley, Karakoram Himalaya, India. The method was chosen because of its suitability in rugged terrain. Analysis of precipitation data from the glacier as a function of altitude shows a power-law relationship. Accumulation estimates based on this relationship show good agreement with the recorded precipitation. The discharge data from the glacier show high runoff in the ablation seasons of 1986–87, 1987–88, 1989–90 and 1990–91. The mass-balance calculations for these years are negative, the lowest being in 1990–91 (–1084 mm). Positive mass balance in 1988–89 (+358 mm) is attributed to comparatively heavy winter snowfall amounts and comparatively low temperatures during the ablation season. Significantly lower runoff was measured during this season. Negative mass-balance values during 1989–90 and 1990–91 are a result of comparatively dry winters and comparatively warm ablation periods, with monthly mean air temperatures 1.4–5.1 °C higher at the beginning of the ablation season (June and July) than the mean of the last 5 years.