SUSPENDED SEDIMENT TRANSPORT IN MOUNT RAINIER NATIONAL PARK, WASHINGTON

Rapid aggradation of sediment within a glaciated watershed can lead to an increased risk of flooding and may also impact hydroelectric facilities. In order to characterize geographic and temporal variation in sediment transport by glacial meltwater, we collected meltwater samples from four streams at or near glacier termini on Mount Rainier. Preliminary results indicate that meltwater discharge and suspended sediment transport as much as doubled between July and August. Analysis of meltwater samples collected every 2 hours for a 24-hour period shows that suspended sediment transport mirrors changes in stream discharge, decreasing by ~ 25% between diurnal maximum and minimum discharge. Future work will include continued sample collection during fall to shed light on geographic and diurnal variations in suspended sediment transport; these results will extend our documentation of seasonal changes in sediment transport through the end of the ablation season. We will also measure cation concentrations in meltwater to provide additional information about glacial erosion on Mount Rainier.