Isotopic composition of ice cores and meltwater from upper fremont glacier and galena creek rock glacier, wyoming

AbstractMeltwater runoff from glaciers can result from various sources, including recent precipitation and melted glacial ice. Determining the origin of the meltwater from glaciers through isotopic analysis can provide information about such things as the character and distribution of ablation on glaciers.A 9.4 m ice core and meltwater were collected in 1995 and 1996 at the glacigenic Galena Creek rock glacier in Wyoming's Absaroka Mountains. Measurements of chlorine‐36 (36Cl), tritium (3H), sulphur‐35 (35S), and delta oxygen‐18 (δ18O) were compared to similar measurements from an ice core taken from the Upper Fremont Glacier in the Wind River Range of Wyoming collected in 1991–95. Meltwater samples from three sites on the rock glacier yielded 36Cl concentrations that ranged from 2.1±1.0×106 to 5.8±0.3×106 atoms/l. The ice‐core 36Cl concentrations from Galena Creek ranged from 3.4±0.3×105 to 1.0±0.1×106 atoms/l. Analysis of an ice core from the Upper Fremont Glacier yielded 36Cl concentrations of 1.2±0.2×...