Isotopic characteristics of cryospheric waters in parts of Western Himalayas, India

Abstract

Present study has analysed stable isotopic composition (d18O and d2H) of cryospheric waters of Ladakh and Kashmir regions, located in Western Himalayas, India. The samples of glacier ice (11) and melt water stream (10) collected altitude ranging between 3168 and 5465 m a.s.l. have been analysed for d18O and d2H. The measured d18O values of glacier ice varied between -16.5 and -13.8 % in Ladakh, and between -12.8 and -9.6 % in Kashmir region. Study shows that isotopic characteristics of ice samples collected from snout of glaciers in Ladakh and Kashmir region are distinctly different from each other. Melt water samples collected from streams near the snout during September have shown good resemblance with the glacier ice melt of respective region. The d-excess of glaciers and melt water of Kashmir region varied from 21.0 to 25.6 % and from 18.0 to 21.5 % respectively. The d-excess of glaciers of Ladakh region have been found between 13.5 and 16.7 % and of the melt water between 11.6 and 12.6 %. Depleted d18O signature and low d-excess value of glaciers of Ladakh in comparison with that of Kashmir region may be attributed to sublimation process triggered by cold arid climatic conditions. The present study of Kashmir and Ladakh region suggest that isotopic composition of glacier ice is influenced by post depositional alteration, such as sublimation, during snow to glacier ice transformation.