Variations of δ18O in precipitation from the Muztagata Glacier, East Pamirs

Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of 2002 and 2003 collected precipitation samples and measured their oxygen isotopes. The δ18O in precipitation displays a wide range, varying from -17.40‰ to +1.33‰ in June-September 2002 and from -22.31‰ to +4.59‰ in May-August 2003. The δ18O in precipitation correlates with the initial temperature of precipitation during the observing periods. The positive correlation between δ18O and tem- perature suggests that δ18O can be used as an indicator of temperature in this region. The δ18O values in fresh-snow samples collected from two snow events at different elevations on the Muztagata Glacier show a strong "altitude effect", with a ratio of nearly -0.40‰ per 100 m from 5500 m to 7450 m.