Groundwater flow patterns of glacial moraine features in an alpine environment

Recent studies suggest that talus slopes and moraines can be key contributors to groundwater flow in alpine environments. The objectives of this study were: (a) to investigate the variability in groundwater properties of a large moraine-talus field using measurements at an area of groundwater discharge, and (b) to derive insight from this variability into the groundwater source area(s) and flow path(s). Electrical conductivity at 25°C displayed substantial temporal and, especially, spatial variability, increasing from less than 50 to over 250 μS cm^-1 over a 20-m length of the discharge area. Chemical trends suggest the spatio-temporal variability reflects mixing of two distinct groundwater end-members, rather than a single groundwater system with a range of residence times or mineralogical heterogeneity. One end-member is likely associated with moraines in contact with a nearby lake, while the other may indicate flow through fresh talus materials or buried ice. Based on the findings from this first full field season, we also suspect that the end-member flow paths remain relatively isolated, either by physical barriers or rapid flow. Copyright © 2009 IAHS Press.