Exploring ionic content and behavior using a two-component mixing model to investigate groundwater delivery changes in an Alaskan glacial watershed during the summer melt season

Glacial meltwaters contribute unique nutrient loads into their watersheds. Glacial hydrological systems are distinctive and poorly understood. In particular, the changes in water chemistry and delivery are widely unrecognized. Wolverine Glacier in the Kenai Mountains of Alaska is just one of many glaciers that drain into Prince William Sound. My project involves exploration of the physio-chemical variables of its watershed, including ion chemistry, electrical conductivity, and discharge from both grab samples throughout the watershed and from a continuous USGS stream gauge at Wolverine Creek.

Thus far, my research shows that major ion concentrations are significantly different overall and some ions exhibit good linear trends with measured electric conductivity (EC). Of these, Calcium has the most robust linear relationship with EC. This relationship can be used to allow the estimation of Calcium concentration for the season, between April and October. Calcium is also the largest component of samples analyzed for ion content, with highest concentrations in ground water sampling sites throughout the watershed. This information will be used to estimate a baseline ground water delivery rate that can be used in various versions of a simple two component mixing model involving ground and surface water. The model also allows for the constraint of possible ranges of its inputs, such as the highest possible ground water concentration or ground water delivery rate. This would allow us to answer: how does this glacial hydrological system behave in terms of ground and surface water? Can certain regimes be identified? Preliminary results suggest that precipitation and possibly dilution might play a major role in the main component of water delivery to the watershed. I hope to continue to investigate the distinction of water sources, their behaviors, totals and meaning in this ever-changing glacial system while keeping in mind that global climate change might have significant effects on these sources into the future.