On the Characteristics of Nepal Himalayan Glaciers and Their Recent Variation

Abstract

The glaciological investigations were carried out in the Mount Everest region, the Gaurisankar region and the Langtang region of the Nepal Himalaya in 1970 and 1971. Nepal Himalayan glaciers were classified into two types; debris-free glacier and debris-covered one. It is proposed in this paper to call the former the “Clean-type glacier” (C-type glacier) and the latter the “Dirty-type glacier” (D-type glacier).The present termini of all C-type glaciers are located far from the fresh terminal moraines which can be assumed as corresponding to the moraine of the Little Ice Age in the Alps (1750-1850), but those of most of the D-type glaciers are not separate from the terminal moraines.One of the characteristics of Nepal Himalayan glaciers is that the main contribution to the accumulation is snowfalls during the monsoon period (June-Sep.). Therefore, the height of snowline of such glaciers depends on air temperature during the monsoon period which may determine whether precipitation falls on glacier as snow or rain.From the difference of height between the present terminus and the terminal moraine of C-type glaciers, it is conjectured that the air temperature during the monsoon period at the most recent advance of glaciers in the Nepal Himalaya was about 2°C lower than that of the present time.