Glaciological observations of Yala Glacier in Langtang Valley, Nepal Himalayas, 1994 and 1996

Abstract

A glaciological survey was carried out to clarify the variation of Yala Glacier in Langtang Valley, Nepal Himalayas, 1994 and 1996. It was clarified that the glacier terminus retreated drastically in 1990s rather than 1980s. The surface profile of the glacier also showed the rapid lowering in recent two years (1994 - 1996). The flow velocities of the glacier surface have decreased since 1982. These results mean that the shrinkage tendency of the glacier has been accelerated in 1990s. Areal averages of mass balance, accumulation and ablation for a central drainage area along flow lines during the monsoon season in 1996 were obtained as -357, 588 and -945 mm w.e., respectively. It was confirmed that an empirical relation between air temperature and ablation, which was derived from the observation at another glacier in east Nepal in the previous study, could not be applied directly to Yala Glacier.