Preliminary study of stable isotope in Chhota Shigri glacier (H.P) India

English Abstract:

To infer the variation in isotopic composition, stable – water isotope data (δ¹⁸O and δD) from five groups of samples (Fresh snow, old snow, snow core, rain water and melt water samples) collected from Chhota Shigri glacier during summer (2013) were presented. Snow core sample traces the variation of δ¹⁸O with depth. Fresh snow, old snow and melt water collected at different altitude has been focused to explore the altitudinal effect on isotopic composition of these samples. Altitude effect on the variation of isotopic composition is best marked by fresh and old snow while melt water did not encounter such effect. Different pattern of δ¹⁸O variation is observed with altitude for the fresh and old snow. Different trend in the depletion of δ¹⁸O of fresh snow and old snow with altitude shows clear demarcation of changes for winter and summer snow fall. This study shows that large variation of d-excess (-1.14‰ to 24.9‰) of all rain water events reflects the influence of local climatic factors as well as south-west monsoon precipitation. Deuterium excess (d-excess) value (1.92‰ to 7.41‰) of fresh snow confirms influence of south-west monsoonal precipitation. Linear regression analysis was applied to stable hydrogen and oxygen isotope data sets for snow core, precipitation and melt water samples in order to establish the local meteoric water line (LMWL) for Chhota Shigri glacier (HP) India. The LMWL was derived with a regression value of 0.99. The LMWL shows an equation δD = 8.5 δ¹⁸O+12.9.