Date of Award
Andrew G. Fountain
Nisqually Glacier (Wash.), Glaciers -- Washington (State) -- Mount Rainier National Park, Kinematics, Glaciers -- Hydrologic models, Glaciers -- Mass budget (Geophysics) -- Mathematical models
The Nisqually Glacier is one of the best studied glaciers on Mt. Rainier. Data was first collected on the glacier in 1857 and since then a number of kinematic waves have been observed but not extensively studied. The purpose of the thesis is to numerically model the conditions that favor or restrict kinematic wave propagation/initiation and subsequently model the relationship between kinematic wave behavior and the Nisqually Glacier. The numerical models used in this study are 2-D and use bedrock elevation, mass balance, basal sliding, and other equations to simulate alpine glaciers. A perturbation is added instantaneously for a specified time interval to the mass balance of the model glacier to allow for possible kinematic wave formation, and parameters such as ice velocity, ice thickness changes, and time elapsed are subsequently recorded. Through the use of the model, the principal research findings include 1) both magnitude and duration of a mass balance perturbation affect kinematic wave behavior, 2) glaciers on steeper slopes show a greater response to small mass balance perturbations of ~0.5 m. w.e. for 1 year compared to glaciers on less steep slopes, 3) a 6 m. w.e. perturbation for 3 years creates a Nisqually Glacier response similar to those seen from its historical waves, suggesting that there are other factors contributing to kinematic wave formation, and 4) the Nisqually Glacier has prominent advances with all mass balance perturbations, leading to the conclusion that even small increases in the mass balance can show significant length change.
Horlings, Brita I., "The Nature of Kinematic Waves in Glaciers and Their Application to Understanding the Nisqually Glacier, Mt. Rainier, Washington" (2016). University Honors Theses. Paper 248.