IVSS 2024 Reports

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Brought together on the Gulkana Glacier through the Inspiring Girls* Expeditions: Girls* on Ice Alaska, three students examined how the physical location of glacial meltwater affects water temperature and pH. Their objective: to measure and compare the pH and water temperature of glacial meltwater in various locations on and near the Gulkana Glacier. Four locations on the Gulkana Glacier and one on Phelan Creek were sampled over two days with a Hanna Meter probe utilizing GLOBE Hydrosphere water temperature and pH protocols. It was hypothesized that the water temperatures would be highest at a pond at the glacier's base and lowest at the most elevated site. A higher pH further up the glacier and a lower pH towards the bottom were also hypothesized. The highest elevation sites recorded the lowest temperatures. The single, standing water site (Glacier Pond) recorded the highest temperature and lowest pH. Measurements suggest that downstream flow and aquifer recharge for local Coho Salmon habitat are mostly within the preferred salmon range for pH (7-8). Physical location (elevation, ice formation, type of sediment/rock) affected the pH and water temperature of the meltwater sample. Exposure to solar radiation, friction, and kinetic energy from flow are also possible factors. Measuring pH in glacial meltwaters is challenging due to the cold, slow response of equipment and the remoteness of fieldwork. Continued and additional research is needed to determine the effect of Gulkana Glacier's meltwater on salmon dependent on the rivers and aquifers it replenishes. Keywords: Gulkana Glacier, water temperature, pH